What Size Solar Panel to Charge 100ah Battery

Published on: May 27, 2022
Written by Liam Jaxon / Fact-checked by David Rowan

Calculating the right size solar panel is not that difficult if you know the solar size calculating method. But It’s not also easy for a person who just planning to buy solar panels for the first time. Basically, when we buy solar panels we buy it on the basis of battery power. If the solar panel is not compatible with the power of the battery then it will fail to provide the exact amount of charge that the battery needed.

So, at first, we should calculate the total amount of power we need and buy the battery on the basis of this amount and choose the solar panel according to the battery power. Most of the people have a common question about the solar panels that what size solar panel to charge 100ah battery? So here will try to figure out the answer to this common question and some other factors that we should know about solar panels.

Solar Panel Ratings

Normally the production house constructs each solar panel with a power rating of 250 watts. And the cells on each panel determined how much power it can generate from the sunlight. The panels we see on the rooftop either for the residential or commercial area are made of 62 to 72 cells. And the number of cells in a solar panel is increasing.

So, if you have four solar panels installed on your rooftop it can generate 250 watts×4 cells = 1000 kilowatts in an hour of full sunlight. So, this solar power rating will tell you how many panels do you need for your 100ah battery.

Calculating the Solar Panel Size

Think, you have a 12volt 100ah (AmpHr) battery Which is a really small size for your home appliance. Multiply the 12 volts with 100Ah and the result is 1200-amp hours. So how much power does your battery need from a solar panel? As you have four solar panels which are in total 1000 kilowatts.

So, it can produce 1 kilowatt of power an hour. But your 12-volt battery requires 1200 KW to get the full charge. So, you need more power-generating solar panels to charge the rest of the 200Ah. Therefore, you need solar panels that can produce in a total of 1.2 KW.

But your solar panels are not generating power for only 1 hour in a day. If your solar panels get a good amount of power from the total 5 hours of sunlight then they can produce 5 kilowatts a day. So, calculate the number of kilowatts your appliances need daily. If your daily needs are below 5 KW then a series of solar panels (4 panels) is enough to produce the full battery charge.

Even It is possible to charge a 2400AH battery with 1000 KW solar panels. Because the solar panels produce power for the whole day. But it’s not recommended to use 1000KW solar panels for 24 volts 100AH battery which means 2400Ah battery.

Why we are talking about the 5 hours because it’s the peak hour when the solar panels get the proper sunlight. But if we are using a 2400Ah battery with 1000KW solar panels it is not possible to get enough power for the same 5 hours of sunlight. It may be possible if our appliances consume less than 2 or 3 KW a day. But we buy our barriers based on the power consumption rate of our appliances. So, for a 2400Ah battery we should buy 2500KW solar panels.

What is the Minimum Size of the Solar Panel Required to Charge a 100-ah Battery?

The minimum size of the solar panel required to charge a 100-ah battery would depend on the amount of current required to charge the battery. Generally, a minimum of 100 watts of solar panel power is needed to charge a 100Ah battery. However, it is recommended to use a larger solar panel to increase charging efficiency and to ensure the battery is fully charged.

Special Requirements for Charging a 100-ah Battery With a Solar Panel

Yes, there are some special requirements when charging a 100-ah battery with a solar panel. It is important to ensure that the solar panel is rated to charge at least the same amount of current as the battery. For example, if the battery is rated at 100-ah, the solar panel should be rated to charge at least 100-amps. Additionally, it is important to ensure that the voltage of the solar panel is compatible with the voltage of the battery. For example, if the battery is a 24-volt battery, the solar panel should be rated to output at least 24 volts. Lastly, it is important to ensure that the solar panel has a high enough wattage to charge the battery in an efficient manner. The wattage of the solar panel should be at least two to three times the watt-hour rating of the battery.

Mistakes We Do After Calculation

When we are done with the calculation we think 2500KW solar panels are enough for a 2400Ah battery. Our calculation is right if our appliances consume less KW a day than the KW produces by the solar panels.

For instance, if our solar panels produce 20 KW a day and our appliances consume 5 KW a day then It is a good sign for the battery life. Because If we discharge our battery more than 50 percent daily then the battery will not last long.

But if our appliances consume 15KW a day then we should use the double size solar panel which is 5000KW. It will help to get a fast charge and produce more power even if the consumption rate is more than 15 KW.

So here we got the answer for the total solar panels normally we need for a 100Ah battery. For the 24-volt battery, we need 2500KW solar panels and for the 12-volt battery, we need 1205 KW solar panels.

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