To sum up, for long and happy LFP battery life, in order of importance, you should be mindful of the following:
- Keep the battery temperature under 45 Centigrade (under 30C if possible) – This is by far the most important!!
- Keep charge and discharge currents under 0.5C (0.2C preferred)
- Keep battery temperature above 0 Centigrade when discharging if possible – This, and everything below, is nowhere near as important as the first two
- Do not cycle below 10% – 15% SOC unless you really need to
- Do not float the battery at 100% SOC if possible
- Do not charge to 100% SOC if you do not need it
this was a DSL post I think, give
him the kudos for the above part.
the important thing is to use a BMS so you don't overcharge. The Electrodacus SBMS0 is the BMS.
the way the DSSR20 works is it gives all the current it can(amps) from the solar PV panels. the DSSR20 is designed to work with 60 and 72 cell PV panels but can also work with 30 and 36 cell panels for 12-volt setups.
I have a 24-volt stationary system.
the 2P8S 13,926.4 Wh battery routinely charges every day if there is enough sun with only 6 panels 1.5kw array. and I have it connected to a load all the time so it gets daily exercise. more at night for light in the barn for the baby critters.
I do not need to use any other external charger. I depend on the sun for charging by using the DSSR20 as the solar charge controllers.
I built an insulated solar power shed for all the batteries and electronics so freezing is not an issue.
I keep my batteries between 30 and 90 percent state of charge. I do not want to get every last possible watt nor do I need to (no reason to overstress the LiFEPO4 batteries.
the Lishen 272Ah cells are almost identical to the Eve brand (280Ah) in weight and appearance.
I was a bit worried/concerned that the cells could be overcharged by using the benchtop chargers initially during attempted top balancing, but the 272Ah cells take a lot of power to get to the higher voltage so I did not overcharge any on my 1st 16 cell 2P8S build or my subsequent builds.??
the Electrodacus SBMS0 has the setting you want to prevent overcharging and they also control the DSSR20's up to 30 of them I think but my current build is utilizing 20 of them for 10,000 Watt PV array.
you can get newer higher watt 60 cell panels or 72 cell panels for more money of course, but economy makes the most sense for my off-grid build on the country acreage -- mounting space is not an issue. every 6 panels are about 10 feet wide and 8 feet deep on the triangle 45-degree fixed angle ground mount array. so it will be 7 of those although I may use some as a roof structure/carport(70 feet x 8 feet ground footprint or 560 square feet). still, real estate for this 10,000-watt array is not an issue. The ruminants could sleep under them when it is time to re-digest the pasture!? easier than a lawnmower and/or tractor to maintain the pasture.
an acre = 43560 square feet;
1 acre is approximately 208.71 feet × 208.71 feet
43560sf /560sf/array = 77.785 so one could build 77.78 of these 10,000 watt arrays on an acre. (slightly less as you would need some maintenance access space)
I think one could solar PV power many homes/structures with some effort.
more later,
cheers all!