Based on over 10 years experience，Temank have become popular among customers all over the world. Up to now, our customer also have come up with many queries, advice and suggestion about Solar Controllers, Micro Grid Tie Inverters, Solar Lamps, MC4 Connectors and other Solar Related Products. There are some regular queries and solution for you to reference. If you have any questions or advice, please contact us via email: email@example.com.
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Q: What's the difference Temank and PowMr?
A: The brand Temank and PowMr are all our company brand. They are all belong to our company.
Q: How long i receive the product when i pay for your product?
A: You receive the product(s) according to your address. We have six warehouses in five conutries including Australia, United Kingdom, Germany, America, China. please visit the page as below:
Q: How many product category are your company launch?
A: We have Solar Controllers, Micro Grid Tie Inverters, MC4 Connectors, Solar Panel, Solar System and other solar products.
Q: Are all your items in stock on your website?
A: Generally speaking, all of our items on the website are available. But some items may be out of stock because of strong demand. If you place an order for it, in any case it is not available, we will contact you ASAP, process either suggest you to choose the other similar item or process a promptly refund to your account according to your demand.
Q: What is a solar charge controller?
A: A solar charge controller is a device that acts as the interface between solar PV modules and batteries. It does the following:
Limits the rate at which current is added to batteries. If batteries are charged at rates higher than their recommended rates, it reduces battery life.
Prevents the battery from over-charging, which reduces battery life drastically. Over-charging or charging abusively can also lead to emission of gases, both in the case of FLA batteries as well as VRLA batteries.
Limits the rate at which current is drawn from the batteries. If batteries are discharged at rates higher than their recommended rates, it reduces battery life.
Prevents the battery from over-discharging, which reduces battery life drastically, especially if the batteries are not designed to handle deep discharge conditions. Overcharging or charging abusively can also lead to emission of gases, both in the case of FLA batteries as well as VRLA batteries.
Essentially, a solar charge controller does the job of increasing the life of batteries to the extent possible.
Q: What does “rated voltage” mean in the context of a solar charge controller?
A: Rated voltage is the battery voltage that a solar charge controller is designed to work with. It is usually 12V, 24V, or 48V.
For a 12V solar charge controller, you can use one 12V battery, or two 6V batteries in series, or six 2V batteries in series.
For a 24V solar charge controller, you can use two 12V batteries, or four 6V batteries in series, or twelve 2V batteries in series.
For a 48V solar charge controller, you can use four 12V battery, or eight 6V batteries in series, or twenty four 2V batteries in series.
Q: What does “full charge cut-off” mean in the context of a solar charge controller?
A: Full charge cut-off is the voltage to which the battery has to be charged. It is also the voltage at which battery charging stops. It varies from battery to battery. Read the battery specifications properly and set the full charge cut-off accordingly.
Q: What does “low voltage cut-off” mean in the context of a solar charge controller?
A: Low voltage cut-off is the voltage at which the battery discharging stops. It varies from battery to battery. Read the battery specifications properly and set the low voltage cut-off accordingly.
Q: What does “reconnect voltage” mean in the context of a solar charge controller?
A: When the low voltage cut-off is reached, battery stops discharging and starts charging again, which leads to increase in its terminal voltage. Reconnect voltage is the voltage at which the solar charge controller allows the battery to be discharged again.
Q: What are the two types of solar charge controllers?
A: The two types of solar charge controllers are: PWM solar charge controller and MPPT solar charge controller.
Q: What does PWM stand for?
A: PWM stands for Pulse Width Modulation.
Q: What is a PWM solar charge controller?
A: A PWM solar charge controller uses pulse width modulation to slowly lower the amount of power added to the batteries as they get closer to getting fully charged. This technique allows the battery to be more fully charged, while putting minimal stress on the battery. Therefore, the battery life is extended quite a bit.
A PWM solar charge controller can also keep the battery in a fully charged state (called “float”) indefinitely.
Q: What does MPPT stand for?
A: MPPT stands for Maximum Power Point Tracking.
Q: What is an MPPT solar charge controller?
A: An MPPT solar charge controller is more advanced compared to a PWM solar charge controller. So it does everything that a PWM solar charge controller does. Additionally, the most important thing that it does is extract maximum power from the solar PV modules, which is why it gets its name.
Q: What is an Inverter?
A: An inverter is a device which a DC (Direct Current) input and produces an AC (Alternating Current) output.
More often than not, the DC input is taken from a battery. However it can also be from solar PV modules in the case of solar applications.
The AC output is for running household appliances like tubes, fans, air conditioners, refrigerators, TVs, computers, etc. and also for industrial appliances.
Q: Why is an Inverter so called?
A: The inverter has got its name from a commutator which originally were large rotating electromechanical devices. They combined a synchronous ac motor with a commutator so that the commutator reversed its connections to the ac line exactly twice per cycle resulting in “AC-in DC-out”. However, if one inverted the connections to a converter,one could put DC in and get AC out. Hence an inverter was an “inverted” converter and that is how they got their name.
Q: What are the two types of Inverters?
A: The two main types of inverters are: pure sine wave inverters and modified sine wave inverters.
Pure sine wave inverters, as their name suggests, produce a pure sine wave output which is identical to the power that we get from the grid. Many household appliances like digital clocks, battery chargers, light dimmers, variable speed motors, and audio/visual equipment require a pure sine wave, and therefore it is advisable to power them with pure sine wave inverters. If you do that, it will ensure that all these “sensitive” loads will work properly and last a long time.
Modified sine wave inverters, as their name suggests, do not produce a pure sine wave output; their output is a “stepped wave” which is obviously not as smooth as a pure sine wave. They achieve voltage regulation by varying the pulse width according to the battery voltage and the load. The stepped wave output is not good for “sensitive” loads and can damage them. It also causes a buzzing sound in stereos and ceiling fans. However, modified sine wave inverters should not be underestimated; they are highly capable and by narrowing the waveform they save energy when running only small loads, as happens during most of the day in a typical home. Modified sine wave inverters were successful at one point, and still are to a large extent. However, more and more companies are not coming out with only pure sine wave inverters as the incremental cost to produce pure sine wave inverters reduces with advances in technology.
Q: What is a solar Inverter?
A: A solar inverter is a device that converts the (constantly varying) DC output of a solar PV module – the input to the solar inverter –into AC. A solar inverter is necessarily a part of a solar PV installation or a solar PV power plant.
Q: What are the types of solar Inverters?
A: There are three main types of solar inverters: off-grid solar inverters, grid-tied solar inverters, and hybrid solar inverters.
Q: What are off-grid solar Inverters?
A: Off-grid, as their name suggests, work “off the grid” which means that they are not connected to the grid. Off-grid solar inverters are also called standalone solar inverters.
Q: What are other components that are typically used along with off-grid solar inverters?
A: The other components that are typically used along with off-grid solar inverters are:
Solar PV modules
Solar charge controller
Q: What does an off-grid solar PV system look like?
The figure above shows what an off-grid system looks like.
Solar PV modules generate DC electricity which is the input to the solar charge controller.
The solar charge controller takes the DC electricity generated by the solar PV modules and stores it in the batteries. Typically, the solar charge controllers also do one other job which is Maximum Power Point Tracking, or MPPT in short. More information on maximum power point tracking can be obtained in the solar charge controller FAQssection.
The batteries convert the electricity (or electric energy) into chemical energy and store it in them. Normally, batteries used along with inverters are called into action (or come into play) only there is grid failure. However, in case of solar applications, these batteries are called into action every single day. Also, they are discharged quite a bit, by as much as 80%, which is the maximum that you can discharge them without impacting their lifetime adversely. This is done so that the batteries are in a fully discharged condition when the sun rises again so that all the electricity generated by the solar PV modules can be stored in them again.
That is why the batteries used in solar applications are deep discharge batteries, or batteries that can withstand daily deep discharges.
The inverter converts the chemical energy stored in the batteries into electricity (or electric energy). The input to the inverter (energy stored in the batteries) is DC whereas its output is AC. This off-grid solar inverter is very much like a normal inverter, but is called a solar inverter because it is used in a solar application.
The loads are household appliances like fluorescent lamp, tube light, fan, refrigerator, TV, computer, pumps, among others.
Q: What are the different types of off-grid solar PV systems?
A: The different types of off-grid solar PV systems are:
Solar power packs: They can vary from small to large size. The small ones have only a DC output and are used to charge mobile phones and run other DC applications. The larger ones have an inverter as well and are used to AC appliances.
Solar home lighting systems: These can vary from small to large sizes. The small ones can be used to power 1 lamp while the larger ones can be used to power multiple lamps. Typically, solar home lighting systems have only a DC output. So the lights that they power should necessarily be DC powered.
Solar lanterns: These can have the solar PV module and battery integrated into the product, or have the battery integrated into the product but have a separate solar PV module in case of higher capacity lanterns. Typically, solar lanterns allow the users to select the luminosity level; lanterns run for fewer hours on higher luminosity levels and for longer hours on lower luminosity levels. Solar lanterns are always DC powered.
Solar street lights: Solar street lights comprise of pole, luminaire, solar PV module, solar charge controller, and battery. The luminaire is always DC powered. It almost always has an IP65 environmental rating since it is exposed to the elements. In many cases, the charge controller is embedded inside it. In some cases, even the battery is embedded inside it. If that is the case, then the batteries are invariably Li-ion batteries since they have to be compact.
Solar signage’s (or signboards): Solar signage’s or signboards are very much like solar street lights and have the same components as compared to solar street lights.
Solar pumps: Solar pumps have solar PV modules and a three-phase inverter which drives the pumps. Solar pumps do not have batteries since there is no need to store the energy. Whenever the solar PV modules produce electricity, it is used to pump water from the well to the ground level (actually in storage tanks that are slightly above the ground level). And since solar pumping systems do not have batteries, they don’t have solar charge controllers as well.
Q: Is it a must to have solar inverters in an off-grid solar PV system?
A: No. An off-grid solar PV system is possible and can be functional without solar inverters. However, in that case the loads have to be DC loads. In other words, the loads should be capable of being powered by a DC source.
Solar charge controllers have a DC output which can be used to power DC loads. A 12V solar charge controller will have a 12V DC output, whereas a 24V solar charge controller will have a 24V DC output. In general, a solar charge controller will have a DC output which is the same as its voltage rating.
Solar power packs, solar home lighting systems, solar lanterns, solar street lights, and solar signages are systems which have DC outputs and therefore do not have/needinverters.
Q: What are the advantages of an off-grid solar PV system?
A: The main advantages of an off-grid solar PV system are:
It can generate power (and that too very reliably) in remote locations where no other source of power is available. There are many locations where the grid can be taken but it becomes prohibitively expensive, and therefore off-grid solar PV systems, despite their high upfront cost, are a better option.
Diesel Generators (DGs) are an alternative to off-grid solar PV systems in certain situations, but they have high running costs, and is getting costlier with every passing day. The supply chain – to supply diesel to these remote locations – can be a daunting task. And of course, DGs cause a lot of pollution and are harmful to the environment.
All the other advantages of solar power (free, unlimited, non-polluting, last for many years) apply to off-grid solar PV systems as well.
Q: What are the disadvantages of an off-grid solar PV system?
A: The main disadvantages of an off-grid solar PV system are:
Cost: Off-grid solar PV systems are quite costly. Solar PV modules are quite costly and contribute a god percentage of the overall system cost. Additionally, off-grid solar PV systems also require batteries, and that too deep cycle batteries, which are quite costly too. That increases the system cost as well.
Maintenance: Since off-grid solar PV systems need batteries, it automatically means that they need to be maintained properly. This mainly involves adding distilled water to the batteries (or “topping up” as it is popularly called) if they are of the flooded lead acid type, which they are in many cases. Although flooded lead acid batteries have advanced quite a bit in the recent years and don’t require frequent topping up, it still needs to be done and can be cumbersome if the place of installation is not easily reachable.
Recurring expenses: Off-grid solar PV systems need batteries, and even if you maintain them well, they will wear out in anywhere from 300 to 1000 cycles. (In most cases, these are typical cycle numbers. Batteries that last longer are prohibitively expensive in which case it is what the first disadvantage talks about.) So off-grid solar PV systems necessarily have recurring expenses associated with them.
Q: What is a grid-tied solar Inverter?
A: A grid-tied solar inverter, as its name suggests, is a solar inverter that is connected to the grid or “tied” to the grid. A grid-tied solar inverter is also called grid-connected solar inverter.
Q: Which other components are used along with grid-tied solar Inverters?
A: The main other components used along with grid-tied solar inverters are solar PV modules and metering equipment (to measure the electricity generated by the solar inverters).
Q: What does a grid-tied solar PV system look like?
The figure above shows what a grid-tied solar PV system looks like.
Solar PV modules generate DC electricity.
The grid-tied solar inverter converts the DC electricity generated by the solar PV modules and into AC and feeds it into the grid.
The sell meter (or the export meter) measures the electricity fed by the grid-tied solar inverter into the grid.
The purchase mater (or the import meter) measures the electricity drawn from the grid.
Q: Does a grid-tied solar PV system shown in the figure above need support from the state electricity boards?
A: Yes, the grid-tied solar PV system shown in the figure above needs support from the state electricity boards in two ways:
The state electricity boards need to give you permission to feed electricity into the grid.
The state electricity boards need to pay you and pay you well for the electricity fed into the grid. Otherwise, it is not economically viable/feasible/attractive.
Q: What are the advantages of a grid-tied solar PV system?
A: The advantages of a grid-tied solar PV system are:
Simple: A grid-tied solar system is simple with fewer components.
Cost-effective: Since there are no batteries in a grid-tied solar system, it is cost-effective since batteries cost quite a lot. A solar system with batteries can cost anywhere from 50% to 100% higher compared to a solar system without batteries.
Easy to maintain: Batteries need regular maintenance to ensure that they work properly and last long. However, since a grid-tied solar system does not have batteries, it is a lot easier to maintain. The solar PV modules need to be cleaned periodically. And the inverters need to undergo preventive maintenance every once in a while.
Apart from the advantages stated above, grid-tied solar PV systems have all the advantages of solar power (free, unlimited, non-polluting, last for many years).
Q: What are the disadvantages of a grid-tied solar PV system?
A: The main disadvantage of a grid-tied solar PV system is that it can’t be implemented without support from the state electricity boards.
Q: What is a grid-connected solar Inverter?
A: A grid-connected solar inverter is the same as a grid-tied solar inverter.
Q: What is a grid-paralleled solar Inverter?
A: A grid-paralleled solar inverter is the same as a grid-tied solar inverter. It is also “tied”or “connected” to the grid. However, there is a slight difference in semantics of it. Grid-paralleled solar inverters imply a “behind the meter” connection and feed the loads in parallel to the grid.
Q: What are the typical capacities of grid-tied Inverters?
A: The capacities of grid-tied inverters vary greatly, from 1 kW all the way up to 1 MW. The smaller capacity inverters are called string inverters, whereas the higher capacity inverters are called central inverters.
Q: What are string Inverters?
A: Small capacity grid-tied inverters are called string inverters. Their capacities vary from 1 kW all the way up to 50 kW.
They are so called because they take “strings” of solar PV modules as inputs.A string of solar PV modules is nothing but many solar PV modules connected in series.
Q: What is the maximum number of solar PV modules that I can connect in a string?
A: The number of PV modules in a string is determined by the open circuit voltage (VOC) of the PV module and the maximum voltage that the inverter can safely withstand at its input. For example, if the VOC ofa module is 44.68V and the maximum voltage that the inverter can safely withstand is 1000V, then the maximum number of PV modules that can be connected is 22.38. Since we have to take the maximum integer less than this number, we can connect a maximum of 22 PV modules in series.
Q: Do String Inverters have multiple MPPT inputs? If yes, why?
A: Yes, string inverters typically have multiple MPPT inputs. This allows the inverter to do maximum power point tracking of different sets of strings differently and independently.
For example, if the string inverter allows 6 strings to be connected to it and if it has 2 MPPT inputs, then it will internally divide the strings in two groups and track them independently. How the string inverter groups the 6 strings depends on the inverter: it could put 3 in one group and 3 in another; it could put 5 in one group and one in the second group (SMA inverter actually does that).
This feature comes in handy where the two sets of strings are expected to have a different maximum power point. Let’s say you have one part of the roof pointing in the south-east direction and the other part pointing in the south-west direction. Then these two sets of strings will have different maximum power points; they have a different azimuth and therefore the angle of incidence of sun’s rays will be different.
Q: What are the advantages of string Inverters?
A: The advantage of string inverters are:
Flexibility: String inverters offer the highest design flexibility which is one of their main advantages.
High efficiency: String inverters have very high efficiency. The state-of-the-art string inverters have >98% efficiency. Also, since string inverters optimize only a few strings together, that leads to higher system efficiencies, especially if there is shading on some modules, or some modules are faulty or underperforming compared to the other modules, or if the orientation/slope is different areas.
Robust: String inverters are quite robust, which leads to low total cost of ownership.
Redundancy: String inverter based designs have a high redundancy by definition. If one inverter goes down, the output of only that inverter is lost; all the inverters are not affected in any way and continue to function.
Fewer BoS components: If big solar PV power plants are constructed using string inverters, they require fewer Balance of System (BoS) components compared to when a central inverter is used.
Lesser DC wiring:If big solar PV power plants are constructed using string inverters, they require lesser DC wiring compared to when a central inverter is used.
Cost effective: String inverters represent a very good value for money, especially for capacities from 10 kW to 30 kW.
3-phase variations: String inverters come in 3-phase variations which is desirable and required in many cases.
Well-supported: String inverters, if bought from reputed companies, are backed up with very good after-sales support, which is essential for resolving issues, if and when they crop up.
Q: What are central Inverters?
A: Central inverters are essentially string inverters except they have very high capacities. The smaller central inverters have a capacity of 100 kW and the bigger ones might have a capacity as high as 1 MW or even more.
Q: What are the advantages of central Inverters?
A: The main advantages of central inverters are:
Optimal when generation is uniform: If central inverters are used in places where the solar power generation is fairly uniform, then central inverters are quite optimal when it comes to energy production.
Highly reliable: Although central inverters, by design, do not have any redundancy built into the system – if they fail, the entire system goes down – they are quite reliable, especially in recent times and if they are bought from Tier I and Tier II companies.
Cost effective:Central inverters are more cost effective in big utility-scale solar PV power plants as compared to when string inverters are used. And this is despite the fact that using string inverters requires fewer BoS components and lesser DC wiring which is expensive.
Q: What size inverter do I need?
A: When choosing an inverter, make sure it's properly rated for your appliance. Check your appliances power requirement specification in the manual and then choose a model that has a continuous power rating that exceeds your appliances requirement. A good rule of thumb is to choose one that exceeds the requirement by about 20%. If you do plan to power additional devices off your inverter, add the wattage of all devices again, add at least 20%, and size the inverter accordingly. When running a microwave make sure you read your microwave power rating properly, the rating of cooking power will be lower than the actual power rating. The actual power (wattage W) rating will be found on a label on the back. Fridge freezers are a little more trickier to size an inverter for, as they can draw up to ten times their power rating when the compressor kicks in.
The most important thing to remember when choosing your inverter is to look carefully at the continuous power rating in the power inverters specifications, the surge power rating can almost be ignored and should not be used for sizing purposes.
Our 150W Power Inverter will run continuously at 150 watts, with up to 300 watt surge
Our 300W Power Inverter will run continuously at 300 watts, with up to 600 watt surge
Our 1000W Power Inverter will run continuously at 1000 watts, with up to 2000 watt surge
Our 3000W Power Inverter will run continuously at 3000 watts, with up to 6000 watt surge
Please Note: Inverters will only operate at their surge capacity for a limited amount of time and then will shut down.
Q: How much power do inverters use?
A: To calculate an approximation of what power the inverter may use, first find the power (wattage) rating of the appliance that will be used with the inverter and divide this wattage by eleven. So a small TV taking 100W (watts at 240vac) will be taking approximately 9 amps an hour off the battery.
Running an inverter will discharge the batteries overtime, but most inverters have battery over discharge protection. Once your battery drops to a certain point the inverter will sound an alarm or shutdown to let the user know battery power is getting low.
It is important to remember that to get the best performance from an inverter a good battery source is needed.
Most inverters draw a continuous current when they are switched on, even when nothing is connected to the output. This residual standby current could be around 0.3-1A or more depending on the size of the inverter. This may not sound like a lot, but if the inverter is left switched on for 24 hours and has a standby current of 1Ah then it could drain 24Amps from the batteries so it is important to switch the inverter off when not in use to preserve battery life.
Q: What does FLA stand for?
A: FLA stands for Flooded Lead Acid batteries.
Q: Why are flooded batteries so called?
A: Flooded batteries are so called because they contain an excess of electrolytic fluid so that the plates are completely submerged.
As the batteries discharge, the chemical reaction produces oxygen and hydrogen which are released from the batteries. As a result, the electrolytic fluid starts reducing. But it should never be allowed to fall below the top part of the plates, thus exposing them. If that happens, the plates will get damaged and their life will reduce considerably. That is why they have to be periodically filled with distilled water to maintain the electrolytic fluid level above the top part of the plates.
Q: What are the advantages of flooded batteries?
A: Advantages of flooded batteries are:
Long proven history of use
High discharge rate capability
Perform better in hot climates
Perform better than VRLA batteries when regularly in a partial state of discharge
Lowest price of all the battery types
Q: What are the disadvantages of flooded batteries?
A: Disadvantages of flooded batteries are:
Have a higher self-discharge rate as compared to VRLA batteries
Need to be periodically refilled with distilled water
Can only be used in an upright position
Produce gas while charging and so require ventilation
Cannot be kept in the vicinity of any electrical equipment or any inflammable material
May emit acid spray if overcharged abusively
Cannot be shipped by air
Q: Do I have to periodically add distilled water to flooded batteries?
A: Yes, you have to periodically add distilled water to flooded batteries. The level of the electrolytic fluid in the battery must be maintained between the min and max levels at all times to ensure that the battery works properly and doesn’t become dry. If the battery becomes dry, its life reduces drastically.
Q: How often do I have to periodically add distilled water to flooded batteries?
A: Typically, you will have to add distilled water to flooded batteries once in 6 months, if the battery and its charger are in good condition. But it is better to check the electrolytic fluid levels once a month. If the level goes down earlier than 6 months, it means that there is some problem with the battery and/or its charger and needs to be looked into.
Q: What does “top up of flooded batteries” mean?
A: To “top up” means to add distilled water to flooded batteries. They are one and the same thing.
Q: Do flooded batteries give more current as compared to maintenance free batteries?
A: Yes. As a general rule, flooded batteries give more current compared to maintenance free batteries. So for applications that need high currents, flooded batteries are more suitable. However, they will need periodic maintenance.
But please check the technical specifications documents of the batteries that you are planning to use for the exact details.
Q: Do flooded batteries perform better than maintenance free batteries in hot climates?
A: Yes. As a general rule, flooded batteries perform better than maintenance free batteries in hot climates. But please check the technical specifications documents of the batteries that you are planning to use for the exact details.
Q: Are flooded batteries cheaper compared to maintenance free batteries?
A: Yes, flooded batteries are cheaper compared to maintenance free batteries, and significantly so in many cases.
Q: Do flooded batteries have a higher self-discharge rate as compared to maintenance free batteries?
A: Yes. As a general rule, flooded batteries do have a higher self-discharge rate as compared to maintenance free batteries. What that means is that you will be able to store them for lesser amount of time compared to maintenance free batteries, before they will need to be charged.
Q: Can flooded batteries be operated only in an upright position?
A: Yes, since flooded batteries are “flooded” with electrolytic fluid, they need to be operated in an upright position.
Q: Do flooded batteries produce gas while charging?
A: Yes, flooded batteries produce gas while charging. That is why need to be kept in a place which is properly ventilated.
Q: Can flooded batteries be kept in the vicinity of any electrical equipment or any inflammable material?
A: No. Since flooded batteries produce gas while charging, they cannot be kept in the vicinity of any electrical equipment or any inflammable material.
Q: Do flooded batteries emit acid spray?
A: Yes, flooded batteries can emit acid spray if overcharged abusively. Please follow the safety instructions while handling flooded batteries.
Q: Can flooded batteries be shipped by air?
A: No, flooded batteries cannot be shipped by air.
Q: Do you have flooded lead acid batteries?
A: Yes, we have flooded lead acid batteries.
Q: What different types of flooded lead acid batteries do you have?
A: Yes, we have flooded lead acid batteries. The range is called Tubular Eco. Please visit its web page for detailed technical specifications.
Q: What does VRLA stand for?
A: VRLA stands for Valve Regulated Lead Acid. VRLA batteries are maintenance free batteries and vice versa. They are one and the same.
Q: What does SMF stand for?
A: SMF stands for “Sealed Maintenance Free”. SMF batteries are maintenance free batteries and vice versa. So maintenance free batteries, SMF batteries, and VRLA batteries are all one and the same.
Q: Why are maintenance free batteries called VRLA batteries?
A: VRLA batteries work on the oxygen recombination principle. However, the recombination process is not 100% efficient. So over time, the internal pressure increases, and some amount of gases have to be released to maintain the ideal pressure. This is achieved with the help of one-way, pressure-sensitive valves which open when the internal pressure increases above a certain threshold and allow the excess gases to be vented. That is why these batteries are called VRLA or valve regulated lead acid batteries. Excess gases are also produced if these batteries are overcharged or discharged at rates higher than the recommended rate.
Q: What is the basic principle of operation of maintenance free batteries?
A: In flooded batteries, oxygen and hydrogen are produced when the batteries discharge. These gases escape from the battery, which leads to loss of water. That is why flooded batteries have to be periodically filled with distilled water.
However, in the case of maintenance free batteries, the oxygen and hydrogen combine to form water. That is why they remain moist and don’t have to be periodically filled with distilled water.
Q: What is the oxygen recombination principle?
A: Oxygen recombination principle is the main principle of operation of maintenance free batteries, and is what makes it possible to have maintenance free batteries.
In flooded batteries, oxygen and hydrogen are produced when the batteries discharge. These gases escape from the battery, which leads to loss of water. That is why flooded batteries have to be periodically filled with distilled water.
However, in maintenance free batteries, oxygen released from the +ve plate travels to the -ve plate where it combines with hydrogen to form water. It is because of this recombination that maintenance free batteries remain moist and don’t have to be periodically filled with distilled water.
Q: Is the recombination efficiency 100%?
A: No, the recombination efficiency is never 100%! It is always less than 100%. But how less is what separates the good batteries from the not so good ones.
EverExceed maintenance free batteries have a recombination efficiency of more than 99% for most batteries, and in some batteries it is even higher than that. And that is the main reason for their superior performance.
Q: If the recombination efficiency is not 100%, what happens to the gases that are emitted?
A: The gases that are emitted collect in the maintenance free batteries, which leads to a rise in the internal battery pressure. When the pressure exceeds a threshold, the one-way pressure sensitive valves open and release the gases bring the internal battery pressure back to the ideal levels.
That is why maintenance free batteries are called “valve regulated lead acid” batteries, or VRLA in short.
Q: What are the advantages of maintenance free batteries compared to flooded batteries?
A: The advantages of maintenance free batteries compared to flooded batteries are:
They do not produce gases during normal operation or while charging. Therefore, they can be kept in the vicinity of any electrical equipment or any inflammable material, unlike flooded lead acid batteries.
They do not emit acid spray even if charged abusively. Of course, charging abusively will have an adverse effect on battery life.
They are spill-proof and leak-proof.
They can be used in vertical or horizontal position (which is something that you can’t do with flooded lead acid batteries).
They can be transported without any restrictions:
Surface transport: Classified as non-hazardous material as per DOT-CFR Title 49 parts 171-189.
Marine transport: Classified as non-hazardous material as per IMDG amendment 27.
Air transport: Comply with IATA/ICAO, Special Provision A67.
Q: What are the disadvantages of maintenance free batteries compared to flooded batteries?
A: The disadvantages of maintenance free batteries compared to flooded batteries are:
They cannot provide the kind of discharge currents that flooded batteries can provide.
They are more expensive than flooded batteries.
Q: What are the two basic types of VRLA batteries?
A: The two basic types of VRLA batteries are VRLA AGM and VRLA Gel.
Q: What does AGM stand for?
A: AGM stands for Absorbed Glass Mat. It is a porous glass mat separator with the ability to absorb a large amount of electrolyte while still allowing some pores to be unfilled. These empty pores act as channels for oxygen to move from the +ve plate to the –ve plate. That is why these batteries are called VRLA AGM batteries.
Q: What are the advantages of VRLA AGM batteries?
A: Advantages of VRLA AGM batteries are:
Widest temperature range of all the battery types
Lowest self-discharge rate of all the battery types
Best shock/vibration resistance of all the battery types
Best performance for high power applications
Less expensive than VRLA Gel batteries
Q: What are the disadvantages of VRLA AGM batteries?
A: Disadvantages of VRLA AGM batteries are:
Don’t perform as good as flooded or VRLA Gel batteries in regular deep discharge (>80% DOD) applications
Don’t perform as good as VRLA Gel batteries in low power applications
Q: Do you have VRLA AGM batteries?
A: Yes, we have VRLA AGM batteries.
Q: What different types of VRLA AGM batteries do you have?
A: Please check the “By Technology Type” tab on the Batteries page for all the types of VRLA AGM batteries that we have.
Q: Why are VRLA Gel batteries so called?
A: VRLA Gel batteries are so called because they are VRLA (which is what makes them maintenance free) and they use gel.
Q: What does Gel or T Gel stand for?
A: Gel or T Gel stands for thixotropic gel. Gel batteries or T Gel batteries are the same as VRLA Gel batteries. They are one and the same.
VRLA Gel batteries use a composite separator made of a glass mat bonded to a porous polyethylene or polyvinylchloride sheet. The batteries are then filled with a thixotropic gel mixed with sulphuric acid.
Q: What are the advantages of VRLA Gel batteries?
A: Advantages of VRLA Gel batteries are:
Perform better than VRLA AGM batteries in regular deep discharge (>80% DOD) applications
Perform better than VRLA AGM batteries in low power applications
Q: What are the disadvantages of VRLA Gel batteries?
A: Disadvantages of VRLA Gel batteries are:
Higher self-discharge rate compared to VRLA AGM batteries
Don’t perform as well as flooded or VRLA AGM batteries in cold temperatures (<40° F)
Don’t perform as well as flooded or VRLA AGM batteries when they regularly reach a shallow depth of discharge (<20% DOD)
More expensive than flooded and VRLA AGM batteries
Q: Do you have VRLA Gel batteries?
A: Yes, we have VRLA AGM batteries.
Q: What are the different types of VRLA Gel batteries that you have?
A: Please check the “By Technology Type” tab on the Batteries page for all the types of VRLA Gel batteries that we have.
Q: What is the difference between Lithium batteries and Lithium Ion batteries?
A: There are several important differences. The practical difference between Lithium batteries and Lithium-ion (Li-ion) batteries is that most Lithium batteries are not rechargeable but Li-ion batteries are rechargeable. From a chemical standpoint Lithium batteries use lithium in its pure metallic form. Li-ion batteries use lithium compounds which are much more stable than the elemental lithium used in lithium batteries. A lithium battery should never be recharged while lithium-ion batteries are designed to be recharged hundreds of times.
Q: What are the advantages of Lithium Ion batteries compared to other rechargeable batteries?
A: Lithium-ion batteries have several advantages:
They have a higher energy density than most other types of rechargeables. This means that for their size or weight they can store more energy than other rechargeable batteries. They also operate at higher voltages than other rechargeables, typically about 3.7 volts for lithium-ion vs. 1.2 volts for NiMH or NiCd. This means a single cell can often be used rather than multiple NiMH or NiCd cells.
Lithium-ion batteries also have a lower self discharge rate than other types of rechargeable batteries. This means that once they are charged they will retain their charge for a longer time than other types of rechargeable batteries. NiMH and NiCd batteries can lose anywhere from 1-5% of their charge per day, (depending on the storage temperature) even if they are not installed in a device. Lithium-ion batteries will retain most of their charge even after months of storage.
So in summary; lithium-ion batteries can be smaller or lighter, have a higher voltage and hold a charge much longer than other types of batteries.
Q: What are the disadvantages of Lithium Ion batteries compared with other rechargeable batteries?
A: Lithium-ion batteries are more expensive than similar capacity NiMH or NiCd batteries. This is because they are much more complex to manufacture. Li-ion batteries actually include special circuitry to protect the battery from damage due to overcharging or undercharging. They are also more expensive because they are manufactured in much smaller numbers than NiMH or NiCd batteries. Li-ion batteries are becoming less expensive and over time we should see their price decrease significantly.
Lithium ion batteries are not available in standard cells sizes (AA, C and D) like NiMH and NiCd batteries.
Lithium-ion batteries also require sophisticated chargers that can carefully monitor the charge process. And because of their different shapes and sizes each type of Li-ion battery requires a charger designed to accommodate its particular size. This means lithium ion battery chargers are more expensive and more difficult to find than NiMH and NiCd battery chargers.
Q: Are Lithium Ion batteries available in standard sizes like AA , C or D cell size?
A: No, Lithium-ion batteries are not available in standard sizes. We believe this is because it would be too easy for users to inadvertently put them in a charger not designed for Lithium-ion batteries creating a potentially dangerous situation. (If an alkaline battery is put into the wrong charger it might leak or even burst, but a lithium-ion battery put into a NiCd or NiMH charger not designed for lithium-ion, might ignite. Also, because Li-ion batteries operate at much higher voltage (typically 3.7V per cell) than the 1.2 to 1.5V of most cell batteries, designing a 1.5V lithium-ion cell would be expensive.
Q: What is the difference between "name brand" (Canon, Nikon, Fuji, etc.) Lithium Ion batteries and the other types?
A: Like prescription drugs there is often very little difference between name brand lithium-ion batteries and generic lithium-ion batteries. Camera makers often make very little from the sale of the camera itself, but have high profit margins for the accessories, like batteries and flashes. Not all third party batteries are the same quality as the original battery, but many (including those which we sell) are virtually identical.
Q: What is the best way to store Lithium Ion batteries?
A: Lithium-ion batteries can hold a charge for many months. It is best to store a lithium-ion battery with a partial or full charge. Occasionally, a lithium-ion battery with a very low charge is stored for a long period of time (many months) and its voltage slowly drops to below the level at which its built in safety mechanism allows it to be charged again. If the battery is going to be stored for several months it's a good idea to take it out and recharge it after a few months. Better yet would be to actually use the battery every few months and then leave it partially or fully charged.
Q: If my camera (or other electronic device) uses alkaline batteries can I use Lithium Ion batteries?
A: The answer depends on the particular camera or device. But in many cases you can not. Because the size, shape and voltage of alkaline and lithium ion batteries are different they are not interchangeable. However, some camera makers have designed some of their cameras in a way that allows the camera to work with either AA size batteries or CRV3 type lithium batteries. If your camera or other device can use different types (chemistries) of batteries the User's Manual should mention it. Also check here to see if your camera can use the rechargeable CRV3 batteries that we carry. Important - There are several different kinds of rechargeable CRV3 lithium ion batteries now available under various brands and they cannot use each others chargers - they are designed as a set and have different charging requirements. This is one area, unlike NiCD and NiMH batteries that you need to get one brand of rechargeable battery, and its matching charger, and stick with it.
Another alternative would be to use an external battery pack of some sort. These are sometimes available with Lithium-ion batteries.
Q: If my camera (or other electronic device) uses NiMH or NiCd batteries can I use Lithium Ion batteries?
A: Normally you can not switch between a NiMH or NiCd battery and a lithium ion battery in a digital camera. There are some devices specifically designed to use either type of battery, cell phones are the most common example. If you can use either type of battery, it should say so in the User's Manual.
Q: How should I dispose of Lithium Ion batteries?
A: Lithium ion batteries, like all rechargeable batteries are recyclable and should be recycled. They should never be incinerated since they might explode. Most places that sell rechargeable batteries will also accept them back for recycling.
Q: How long will it take to charge a lithium battery?
A: Lithium iron phosphate batteries can be charged in as fast as 1 hour. We recommend using a rate that charges our batteries in 2-5 hours. Please refer to the data sheet for your particular model, to find the recommended charge rates. All of our data sheets are available on our website within the product section.
Q: What is a BMS? What does it do and where is it located?
A: BMS stands for Battery Management System. The BMS protects the cells from getting damaged — most commonly from over or under-voltage, over current, high temperature or external short-circuiting. The BMS will shut off the battery to protect the cells from unsafe operating conditions. All RELiON batteries have a built-in BMS to manage and protect them against these types of issues.
Q: Can you mount the batteries in any position?
A: Yes, because there is no fluid inside of LiFePO4 batteries. This gives you the flexibility to install the battery where it is best suited for your application.
Q: How do LiFePO4 batteries perform in hot temperatures?
A: LiFePO4 batteries will provide their full capacity and performance until they reach the Battery Management (BMS) protection level. The BMS maximum temperature ranges from 60-80°C (140-176°F).
Refer to the data sheet for your particular model to find the exact upper temperature limit. LiFePO4 batteries produce less heat than other lithium chemistries , but if they reach an upper limit, our BMS will protect the battery by shutting it off.
Q: How deep can a lithium iron phosphate battery be discharged?
A: LiFePO4 batteries can be discharged up to 100% without risk of damage. Make sure you charge your battery immediately after discharge. We recommend discharging be limited to 80-90% depth of discharge (DOD) to avoid the BMS disconnecting the battery.
Q: How does the rate of discharge effect capacity?
A: The rate of discharge for LiFePO4 batteries has virtually no effect on the delivered capacity. This is not the case with lead-acid batteries which have significantly reduced capacity of up to 50% as the rate of discharge increases.
Q: What’s the difference between parallel and series connections?
A: Parallel connections involve connecting 2 or more batteries together to increase the capacity of the battery bank. In this case, the positive terminals are connected together and the negative terminals are connected together of all the batteries until you reach your desired capacity.
Series connections involve connecting 2 or more batteries together to increase the voltage of the battery system. The positive of one battery is connected to the negative of another until the desired voltage is achieved. For example, if you connect 2 x 12V batteries in series, the battery system will be 24V.
Q: What type of solar charge controller do I need to charge my batteries with my solar panels?
A: There are two types of charge controllers. Both work with LiON batteries.
Pulse width modulation (PWM)
Maximum power point tracking (MPPT).
Q: Will a 12V, 100Ah lithium iron phosphate battery give a longer run time than a 12V, 100Ah lead-acid battery under the same conditions?
A: Yes. Lithium iron phosphate batteries provide more useable capacity than a lead-acid equivalently rated product. You can expect up to twice as much runtime.
Q: How are LiFePO4 batteries safer than other lithium batteries?
A: Phosphate-based batteries offer superior chemical and mechanical structure that does not overheat to unsafe levels. Thus, providing an increase in safety over lithium-ion batteries made with other cathode materials. This is because the charged and uncharged states of LiFePO4 are physically similar and highly robust, which lets the ions remain stable during the oxygen flux that happens alongside charge cycles or possible malfunctions. Overall, the iron phosphate-oxide bond is stronger than the cobalt-oxide bond, so when the battery is overcharged or subject to physical damage then the phosphate-oxide bond remains structurally stable; whereas in other lithium chemistries the bonds begin breaking down and releasing excessive heat, which eventually leads to thermal Runaway.
Lithium phosphate cells are incombustible, which is an important feature in the event of mishandling during charging or discharging. They can also withstand harsh conditions, be it freezing cold, scorching heat or rough terrain. When subjected to hazardous events, such as collision or short-circuiting, they won’t explode or catch fire, significantly reducing any chance of harm. If you’re selecting a lithium battery and anticipate use in hazardous or unstable environments, LiFePO4 is likely your best choice. It’s also worth mentioning, LiFePO4 batteries are non-toxic, non-contaminating and contain no rare earth metals, making them an environmentally conscious choice.
Q: What is a solar cell?
A: A solar cell is an electrical device that converts the energy of light directly into electricity by a phenomenon called the photovoltaic effect. It is a form of photoelectric cell (in that its electrical characteristics—e.g. current, voltage, or resistance—vary when light is incident upon it) which, when exposed to light, can generate and support an electric current without being attached to any external voltage source, but do require an external load for power consumption.
Q: What is a solar PV module?
A: A solar PV module consists of many solar cells that are connected together (typically in series) and packaged in a frame (typically made of aluminium). The wattageof solar PV modules varies from 3W to 400W.
Q: What is a solar PV panel?
A: A solar PV panel is a set of solar PV modules that are connected and mounted (either on rooftops or on the ground) with the help of mounting structures.
In small capacity installations, multiple solar PV modules are connected in series. When solar PV modules are connected in series, the voltage of the individual modules adds up. Therefore, the number of solar PV modules that can be connected in series depends on the maximum voltage that the inverter can take as input. It is typically in the 300V-1000V range. For example, ESM300-156 (which is our 300W polycrystalline solar PV module) has Voc of 44.68 and maximum system voltage of 1000V. So you cannot more than 22 of these panels in series. If you decide to connect 20 of these panels in series, you will form a panel of capacity 6000W.
In high capacity installations, multiple small capacity installations are connected in parallel. For example if you want to do a 30kW installation, you will connect 5 panels of 6000W (as described above) in parallel.
Q: What are the different types of solar PV modules?
A: There are two types of solar PV modules: crystalline solar PV modules and thin film solar PV modules.
There are two types of crystalline solar PV modules: polycrystalline solar PV modules and monocrystalline solar PV modules.
Thin film solar PV modules are usually categorized based on the photovoltaic material used. The four main types of materials used are: amorphous silicon and other types of silicon, cadmium telluride (CdTe), copper indium gallium selenide (CIS or CIGS), and dye-sensitized solar cells (DSC) or other organic solar cells.
Thin film solar PV modules are also be categorized in a completely different way: rigid thin film solar PV modules and flexible thin film solar PV modules. Rigid thin film solar PV modules are created by using a glass substrate, while flexible thin film solar PV modules are created on a flexible metallic or plastic substrate. Both, rigid and flexible, thin film solar PV modules can have any of the above mentioned four types of photovoltaic materials.
Q: What are the advantages of polycrystalline solar PV modules?
A: Advantages of polycrystalline solar PV modules are:
They contain silicon crystals of varying sizes and orientations. As a result, they can absorb light from various directions, and therefore they perform better in low-light and diffused-light conditions.
They occupy less space compared to thin film solar PV modules.
They are less expensive compared to monocrystalline solar PV modules.
Q: What are the disadvantages of polycrystalline solar PV modules?
A: Disadvantages of polycrystalline solar PV modules are:
They occupy more space compared monocrystalline solar PV modules.
They are more expensive compared to thin film solar PV modules.
Q: What are the advantages of monocrystalline solar PV modules?
A: Advantages of monocrystalline solar PV modules are:
They have the highest efficiency of all types of solar PV modules, with the exception of CdTe thin film solar PV modules which have higher efficiencies.
They occupy the least amount of space of all types of solar PV modules,with the exception of CdTe thin film solar PV modules.
Q: What are the disadvantages of monocrystalline solar PV modules?
A: Disadvantages of monocrystalline solar PV modules are:
They are expensive compared to almost all types of solar PV modules.
Q: What are the advantages of thin film solar PV modules?
A: Advantages of thin film solar PV modules are:
They are less expensive compared to polycrystalline and monocrystalline solar PV modules.
Q: What are the disadvantages of thin film solar PV modules?
A: Disadvantages of thin film solar PV modules are:
They occupy more space compared to polycrystalline and monocrystalline solar PV modules since their efficiency is 7% to 10%.
Q: Do solar PV modules produce DC electricity or AC electricity?
A: Solar PV modules, irrespective of their type, produce DC electricity. This DC electricity has to be inverted with the help of an inverter if you want AC electricity.
Q: What is the amount of electricity generated by solar PV modules dependent on?
A: The amount of electricity generated by solar PV modules is dependent on many factors. They are:
Solar radiation level: The amount of electricity generated by solar PV modules is directly proportional to the solar radiation level.
Conversion efficiency: The amount of electricity generated by solar PV modules is directly proportional to its conversion efficiency, which in turn is determined by the solar PV module technology.
Angle of incidence: The amount of electricity generated by solar PV modules is highest when the sunlight is perpendicular to the surface of the module. As the angle of incidence increases with respect to this reference, the electricity generated decreases.
Q: How much electricity does a PV panel produce in a day?
A: A 1kWp solar PV panel will produce around 5 units of electricity on a clear sunny day.
Q: How much electricity does a PV panel produce in a month?
A: A 1kWp solar PV panel will produce around 150 units of electricity in a month (5 units per day multiplied by 30 clear sunny days in a year). This amount will be significantly lower during the rainy season.
Q: How much electricity does a PV panel produce in a year?
A: A 1kWp solar PV panel will produce around 1500 units of electricity in a year (5 units per day multiplied by 300 clear sunny days in a year). Areas that get more clear sunny days will product more electricity in a year (up to 15%-20% higher).
Q: Do solar PV modules produce any electricity on cloudy/overcast days?
A: Yes, solar PV modules will produce some electricity on cloudy/overcast days, but it will be significantly less compared to what it will produce on a clear sunny day.
Q: Do solar PV modules produce any electricity on rainy days?
A: Yes, solar PV modules will produce some electricity on rainy days, but it will be significantly less compared to what it will produce on a clear sunny day.
Q: Do solar PV modules produce more electricity in summer?
A: Yes, solar PV modules will produce more electricity on clear sunny day because the solar radiation levels are higher and the sun shines for a lot longer compared to a rainy or cloudy/overcast day. Also, during summer, since the sun is closer to being directly overhead, the rays of the sun are less slanted, and that results in higher electricity generation as well.
Q: Do solar PV modules generate the same amount of electricity every year?
A: No, solar PV modules generate the most amount of electricity in the first year. Their electricity generation capacity goes on decreasing every year by roughly 0.5% per year.
Q: What is the typical life of solar PV modules?
A: The typical life of PV modules is 25 years. However, good quality PV modules can last for even as much as 35-40 years. However, their electricity generation capacity will have reduced considerably by then.
Q: What is the typical power warranty given by solar PV module manufacturers?
A: The typical power warranty given by good solar PV module manufacturers is as follows:
90% of the rated power for the first 10 years
80% of the rated power for the first 15 years
Our solar PV modules come with an even better power warranty:
95% of the rated power for the first 5 years
90% of the rated power for the first 5 years
80% of the rated power for the first 15 years
Q: Can I connect my loads directly to the solar PV module?
A: Yes, if your loads work on DC, then you can connect them directly to the solar PV module. However, the amount of electricity generated by the solar PV modules can vary significantly during a day. Ensure that your DC load is tolerant to these variations and will not get damaged by them.
Q: Will a solar panel produce electricity on a cloudy day?
A: Yes, a solar panel does produce electricity even when it is not placed in bright sunlight. On a normal cloudy day there is always enough so-called diffuse light, by which the panel will produce electricity. However, the production of electricity is not as high as when the panels are placed in bright sunlight.
Q: Will solar panels work in the winter?
A: Yes, solar panels work on light not heat. The amount of sun hours will be less in the winter, as the sun rises later and sets earlier.
Q: Will a solar panel supply electricity 24 hours a day?
A: No, solar panels convert light into electricity. So as the light reduces in the day so does the output of the solar panel.
Q: What size solar panel do I need?
A: This depends on the load you have connected to the battery. You will need to calculate the watt-hour or amp-hours you are using in a period of time (see FAQ How to calculate your solar panel needs), then having a rough idea of the amount of direct sunlight your solar panel will receive each day. The solar panel needs to supply approximately 20% more than your needs to compensate for variables, such as cloudy days etc. Obviously the winter will have shorter sunlight hours per day than the summer, but you can work on an average of approximately 4 hours sunshine a day in the UK over a year.
Q: How can the panels be connected?
A: Solar Panels can be connected in parallel or series.
Solar Panels Connected In Parallel
The diagram above shows 2 x 17 Volt 30 Watt Solar Panels connected in parallel each with a maximum current of 1.76A.
As you can see connecting the two solar panels together in parallel keeps the voltage the same, but doubles the wattage and current.
Solar Panels Connected In Series
The diagram above shows 2 x 17 Volt 30 Watt Solar Panels connected in series each with a maximum current of 1.76A.
As you can see connecting two solar panels in series will double the voltage and wattage, but the current will stay the same.
Q: What is the best orientation of a solar panel?
A: The sun rises in the East and sets in the West, but never goes North. Therefore if the Solar PV is facing South the more direct sunlight it will receive, which will produce more energy. To get the maximum benefit from the Solar Panel it needs to face between the South East and the South West otherwise its energy generation will be reduced. In the UK, the best angle is between 30 degrees and 45 degrees from horizontal.
Q: How to calculate your solar panel needs?
A: Battery Ampere Hour: The amp hour (ah) rating of a battery tells you how much amperage is available when discharged evenly over a period of time. The amp hour rating is cumulative, so in order to know how many constant amps the battery will output for a given period, you have to divide the amp hour rating by the amount of hours the load will be used.
Example: If a battery has an amp hour rating of 85, and it will be used for 20 hours dividing 85 (ah rating of battery) by 20 (hours of load) = 4.25. Such a battery can carry a 4.25 amp load for 20 hours before dropping to 10.5 volts. (10.5 volts is the fully discharged level, at which point the battery needs to be recharged.) Please be aware that it is not a good thing to discharge the battery fully. If the battery is fully discharged the solar panel may not be able to start the recharge, so add at least 20% more to your battery needs.
Please remember that these examples are for guidance only. The ratings of Solar panels are calculated in bright direct sunlight. Conditions such as indirect sunlight, cloudy, hazy conditions and partial shade will decrease the output. Also the length of daylight i.e.: summer vs. winter.
Calculating power using current and voltage
There are three ways of writing an equation for power, current and voltage:
Power = Current x Voltage so:
P = I x V
I = P divided by V
V = P divided by I
P = power in watts (W) P = power in milliwatts (mW)
V = voltage in volts (V) V = voltage in volts (V)
I = current in amps (A) I = current in milliamps (mA)
A milliwatt is a 1000th of 1 watt
A milliamp is a 1000th of 1 amp
Example: The Sunshine Solar Panels 80W - 12V Monocrystalline in peak light conditions will give approximately the following current using one of the above equations. We have the 2 variables, watts and volts so the following equation can be used. If the working voltage of the panel is 18 volts (to enable charging of the battery). I = P divided by V I = 80 divided by 18 = 4.44 amps So as the formula states that a 80 watt solar panel in peak light conditions will supply a current of 4.44 amps an hour.
Example: If we say that a 80 watt solar panel will supply 4.44 amps for a period of 5 hours (in the summer) it will replenish the battery with 22.2 amps in a day. If you have equipment which is connected to the battery that uses more than 22.2 amps per day then the solar panel you have may not be sufficient for your needs, as it will eventually drain your battery. Please remember that these examples are for guidance only. The ratings of Solar panels are calculated with light at 1000 w/m ² at a temperature of 25°. Conditions such as indirect sunlight, cloudy, hazy conditions and partial shade will decrease the output. Also the length of daylight i.e.: summer vs. winter.
Q: What is a blocking diode?
A: This is a component connected within the cable that prevents the solar panel discharging the battery when there is no sunlight.
Q: Can equipment be used directly from solar panels?
A: Yes, solar panels will run equipment direct, these could be loads such as fans and pumps, but make sure the load of the equipment is not equal to the output of the solar panel, as overcast or cloudy days will reduce the output. Solar panels with not run TV's or radio's (without battery backup), as they require a more stable voltage.
Q: Is maintenance required on solar panels?
A: Clean using a non-abrasive cleaner. In the long term check the sealing especially in marine use and reseal with a silicon sealant if damage is suspected. Check battery connections periodically when you check battery levels. Fuse holders and connections should be kept dry and clean.
Q: What are the possible problems?
A: Failure of a solar panel is normally due to water damage to the panel itself or the connections. Also damage to the sealant around the frame could cause failure. Mounting the panel incorrectly. If it is fixed horizontally it may be able to collect water. Not a sufficient air gap beneath the panel can also cause damage.
Q: What problems might there be with mounting a solar panel?
A: Ideally the solar panel should have an incline of 30-40°, but this will be impractical if permanently mounting on a motorhome caravan or boat. Make sure there is an air gap beneath the panel when using solar panels with aluminium frames.