Solar panel charging a 100Ah 12V lithium battery via the charge controller. Alright, let’s set up this task properly. Pretty much any solar panel will be able to charge a 100Ah battery. It just depends on how long it will take. Here are some examples we calculated along the way:
Technically, all you need to charge a 12v battery is a solar panel with a 12v rating. This can be any solar panel, although the bigger it’s, the quicker your battery will charge. Anything under 5–10 watts is not enough, as these will only “trickle charge” your battery very slowly.
As we can see, a 400-watt solar panel will need 2.7 peak sun hours to charge a 100Ah 12V lithium battery. If we presume that we get 5 peak sun hours per day, we can actually fully charge almost two 100Ah batteries (or one 200Ah battery).
A 10kW solar system will charge a 100Ah lithium battery in 6.48 peak sun minutes. That’s quick! To adequately calculate the size of the solar panel to fully charge any 100Ah battery, we have to take a 2-step approach.
12v Battery for Solar Panel (Best Charge for Each Amp) - Solar Panel Installation, Mounting, Settings, and Repair. 12-volt batteries and solar panels are both common items in any arsenal.
For a 12v battery, you’ll ideally need a panel of 200 watts to charge a 100ah battery — the most common 12v battery size. Given that a 200-watt panel can produce around 60 amp-hours per day — on a sunny day under ideal conditions — you should be able to fully charge a 100ah battery with a 200-watt panel in 5–8 hours.