If you lose a cell - you lose the power from both batteries. With dual 6V batteries in series - when they’re dead, they’re dead. Also - if a cell ever goes bad (in one battery) - I still have a 12V battery to rely on. When one is dead - I know I have one in reserve. I prefer running 12V batteries because I can run them independently, one at a time. Don’t leave them in parallel when they’re not charging. I have a marine style dual battery switch to connect them in parallel when charging and run one at a time when discharging. With a 12V battery - you add the two AH ratings together (the batteries are in parallel) to get the total capacity. Two of these are very close to the AH rating of two 6V golf cart batteries. I like the true deep cycle Costco 12V batteries - NOT the ones that mention “starting” (those are hybrid batteries and not TRUE deep cycle). If you get the Trojan T-105 for ~$150ea, you will spend $600 on lead acid. This is especially true if you don’t exceed the 50% discharge rule for longevity. My point is you really need 4 x 6v ~225Ah batteries to match the performance of a single 100Ah lithium. Taking temperatures and degradation into effect that capacity will drop. This assumes it’s a brand new battery in 80+ degree temperatures starting at a full state of charge and willing to use full capacity. Hookup a inverter and pull 75 amps and usable capacity is closer to ~135Ah. That rating is based on 20H rating, means you can’t draw more then ~11 amps/h. Same is not true with lead acid, take a standard Trojan T-105 rated 225Ah. Perkert's law makes lithium 99% efficient. Point taken, just want to be clear that people should’ve fear they must upgrade to use lithium batteries.ġ00Ah of lithium have more usable capacity as ~200Ah of lead acid. Same is true for a charge controller, but many MPPT have user selectable voltages so it may not be a issue. You don’t need to upgrade the charger with lithium with a BMS but it helps to get the most out of them, especially if you want to charge at the best rate.
0 Comments
Leave a Reply. |