LifePo4 Charge Performance
Thinking seriously about replacing our two GC2's with a pair of 100ah LifePo4's. Hearing a lot of chatter about how lithiums accept a charge much quicker than lead cells. Very familiar with how ou...
Forum Discussion
StirCrazy wrote:
for your charging LFP I would assume at 41 they will take a 1C rate, but I will look into it for you some more. My thinking is the actualy charg rate is 4 to 5C and the 1C is an artificial limit put in place by the BMS to prevent us people from overcharging and making to much heat in them which can distort the plates and wreck the battery. there is a drop off in cold but its not as extream as lead acid and such and I am not sure if it would affect them for 99% of the people with a big bank and lower 45-70 amp chargers. at any rate you are not going to dammage the cell as your BMS will control the charge rate as it is monitoring both the voltage of each cell and the tempature of the pack. this is why if you build one dont get a 20 buck BMS, it will work but will not have cold charging cutoff and such. a good BMS will cost 100-150 cdn but will protect your cells properly.
Steve
I believe it may be more about dendrites growing than plate warpage. The dendrites grow, penetrate the cell separators, and short out. The higher the voltage, the faster they grow. That is why the bms limits charging rate. That results in catastrophic failure, which is why I will NEVER have any house bank in my warm living quarters.
In the bad old days of nickel cadmium and nickel metal hydride, sometimes a LARGE voltage could be used to "burn off" the dendrites, allowing for a little more lifespan, but at reduced total capacity.
