diy solar

diy solar

Cold Temp LiFePO4 Charging Test

So the question in my mind is how much of the loss from 176 Ah to 155 Ah is just the reduced capacity of using the batteries at a low temperature and how much is permanent degradation from the damaging effects of charging at low temperature.

This will be interesting.
That is on my mind as well.
As I use mine when outside on my mobility scooter.
 
So the question in my mind is how much of the loss from 176 Ah to 155 Ah is just the reduced capacity of using the batteries at a low temperature and how much is permanent degradation from the damaging effects of charging at low temperature.

This will be interesting.
Yes exactly. I need temp probe and capacity test at room temperature to know. Will repeat test with new cells.
 
Best price for loop tester was 12k$ so I'm doing it manually. I have inverter and charger in parallel so it takes seconds to switch over, but I need something better
 
Can I see that video? I would like to know the genesis of this thread, since I don't understand the discussion without the context. I cannot view the video. I posted another thread about something that might be similar:

 
Ok, so I did a first test charging at -17C. I had the battery hooked up (after it being outside for a few hours) for about an hour, but could only get 2 to 3A of current into the battery. In other words, the internal resistance got so high it was impossible to get power into the battery. After about an hour, I let the battery warm up for a few hours and then charged it fully at 0.5C. I did a 0.2C capacity test an hour after the battery was full and managed full capacity. My guess is that the time I kept the battery on the charger combined with the low power I was able to put in at this temperature prevented any significant damage.

My next step would be to leave the charger on the battery for a longer period of time, however the power supply does not like -17C either and starts acting up. Which brings up an important point: even if you could charge at -17C, would you trust the charge controller, BMS, etc. at those temperatures?
 
Keep the charger inside, and run slightly longer wires to the battery outside?
 
Back
Top