Originally Posted by Tskadberg
Comparing amp hour rating is tricky business. My rule of thumb is that 100 amp hour of lithium is worth 200 amp hour of flooded. Based on my usage, we run an inverter for fridge. Flooded loose a lot of capacity the higher the amp draw. See Peukert's law. The rating on the batteries is based on a 5 amp draw. So if all you use are LED lights your math might be different. You also have to factor in how far you want to discharge your batteries. I went with a 12 volt system so I can easily add a battery if my needs require it. Only way to know is to start somewhere and get YOUR real world usage out of it. If you do and need more then add more when you can.
Some of your statements are wrong .
The 20 hour rating on flooded batteries is based on 5 amps per 100 AH. 200 AH bank =10 amps and on up.
Flooded batteries can safely be cycled down to 30% SOC, so tha/gives you 70% usable capacity.
Lithium can be cycled to 0% but then they shut off. Now you have nothing. So with the proper charger that will bring them up to 100%, you will safely have about 90% usable capacity.
If your using a flooded battery charging system, then your batteries are only charging to 80%. Now you have 70% usable capacity.