Lithium batteries and new solar charger
I am replacing my 4 6V batteries I think 2 lithium, have never been impressed by the 30A PWM charger for my 600W solar, probably my fault for using 8 avg wire on a 9m run. Thinking if I get a Victron ...
Forum Discussion
Slownsy wrote:
Ok the speech from manufacturer is charge to 14.4-14.6 then float at 13.3-13.8V.
The BMS is set to cut out at 11.6V and above 15.0V the 11.6 threshold equates to about 2-5% remaining battery capacity.
The manufacturer recommended to connect loads and charging with 00 cable but my 3000W Magnum hybrid inverter charger specs is for 0000 which is what I currently have but may not be able to fit to batteries and BMS. I have never used over 200A as per my display running microwave fridge etc not HW or air conditioner and according to cable chards 00 can handle 200A for quite some distance.
I would not float at 13.8V. This is what 100% full LFP would have after you've finished charging it at 14.6V, it doesn't need any more current at this point, unless you begin discharging it right then. There is a "knee" at the beginning of discharge, at 5% DOD it drops quickly to 13.1V, then the curve becomes almost flat for a while. You might want to set Float to 13.2-13.3V.
I am also skeptical about 1C charging current (i.e. 200A in your case). My LFP suggests 0.2C as "optimal" charging/discharging, 1C max continuous current <=5 minutes, and max instant current 2.5C <= 5 sec (the latter is for discharge only). It might handle currents higher than 1C for longer but at the expense of the lifespan.
