Obviously this was a (very stupid) mistake on my part.
I should have had implemented better controls to not use the wrong charger.
I have used color coded plugs to prevent this in the past...
However, this time I had a programmable charger that I had used at 58.8V all summer.
I reprogrammed it to 84V for another pack.
Inadvertently used it back on my 14S /58.8V pack and... puff! - a few hours later I had a fireball.
Questions: I'm surprised the the BMS did not cutoff charging once a cell hit 4.2V - what could have caused this overcharging?
Perhaps the FETs were not rated for higher voltages?
Should mention that I had two 14S packs/BMS plugged in parallel while charging - note that I've bulked charged BMS's in parallel for years (at proper voltage) with no issue.
I'd like to hear your thoughts.
PS. No one was hurt - just significant property damage.
I should have had implemented better controls to not use the wrong charger.
I have used color coded plugs to prevent this in the past...
However, this time I had a programmable charger that I had used at 58.8V all summer.
I reprogrammed it to 84V for another pack.
Inadvertently used it back on my 14S /58.8V pack and... puff! - a few hours later I had a fireball.
Questions: I'm surprised the the BMS did not cutoff charging once a cell hit 4.2V - what could have caused this overcharging?
Perhaps the FETs were not rated for higher voltages?
Should mention that I had two 14S packs/BMS plugged in parallel while charging - note that I've bulked charged BMS's in parallel for years (at proper voltage) with no issue.
I'd like to hear your thoughts.
PS. No one was hurt - just significant property damage.