LiFePO4 Battery behavior

[Efried www.hyperbike.cc/register]

Hello,

even I see most of the communication here is spam - one serous
question:

I received a 50Ah LiFEPO4 battery two year ago from China. The charger
connects to every cell so I assumed its save when charging. After
discharging too much at one specific trip the first cells connected to
the + and - cables to the controller for discharging got hot and
ceased life. Two new cells of the same make were ordered and
installed. After reconnecting the charger after charging they inflated
and look funny now. So I had to go for another replacement. In between
I found out how to deflate the cells, by turning a sealed screw at the
top of the cells. So I put the ex-inflated ones back into the pack
because they still show voltage. Before trying out the brand new ones
allow me ask whether you have some explanation of the whole
experience? Unfortunately the seller was not very supportive they even
send me a fast charger now connecting to the pack but not on cell
level (assuming a BMS which I still did not get)

many thanks in advance

Gefried