Joined
·
4,326 Posts
I am wondering why the LiFePO4 cells are irrecoverable after over-discharge. I've had a few fail (all my fault for not stopping when pack voltage started dropping).
Both times I've had a cell fail, it has been just one cell in the whole pack, but once its dead, its really dead and cannot be charged, or kickstarted with a power supply or even a completely dumb external power source like a 12v battery with no controls.
any guesses as to what happens inside the cell? makes me want to take it apart to see, but not enough to actually do it.
It does beg the question though as to how low a voltage a cell can be run until it becomes irrecoverable. and why? i.e does it make a difference if it happens under moderate load while driving, or very gradually due to self discharge or parasitic discharge from controllers while sitting in a garage without periodic charging?
Both times I've had a cell fail, it has been just one cell in the whole pack, but once its dead, its really dead and cannot be charged, or kickstarted with a power supply or even a completely dumb external power source like a 12v battery with no controls.
any guesses as to what happens inside the cell? makes me want to take it apart to see, but not enough to actually do it.
It does beg the question though as to how low a voltage a cell can be run until it becomes irrecoverable. and why? i.e does it make a difference if it happens under moderate load while driving, or very gradually due to self discharge or parasitic discharge from controllers while sitting in a garage without periodic charging?