I have been bulk charging lithium type packs using a lab switching 5A/60V PS for going on 6 months now....for 12 years before that I used a linear 3A/30V lab PS without issue.
However yesterday my 5A/60V bench power supply shot up to maximum pre-regulated DC voltage output @maximum amps without warning.
Fortunately I had just connected up my battery and noticed voltage was climbing fast due higher charge current....as soon as I disconnected the pack, the PS voltage reading shot up to over 80V (and climbing). Within seconds an output capacitor exploded before I could pull the plug.
Repairs involved failure of final-stage MOSFET (gate/source/drain short) and capacitor...the pair of primary transformer winding switching MOSFETS were fine.
Power supply is working again....will not use it anymore though. Will invest in better quality one (suggestions that wont break bank?).
Anyway, if failure had occurred while I was not there I would probably be talking to my insurance agent regarding fire right now.
PS: Pack being charged at time did have BMS, but my other pack does not have BMS.....this could have been very bad outcome.
v/r,
P
However yesterday my 5A/60V bench power supply shot up to maximum pre-regulated DC voltage output @maximum amps without warning.
Fortunately I had just connected up my battery and noticed voltage was climbing fast due higher charge current....as soon as I disconnected the pack, the PS voltage reading shot up to over 80V (and climbing). Within seconds an output capacitor exploded before I could pull the plug.
Repairs involved failure of final-stage MOSFET (gate/source/drain short) and capacitor...the pair of primary transformer winding switching MOSFETS were fine.
Power supply is working again....will not use it anymore though. Will invest in better quality one (suggestions that wont break bank?).
Anyway, if failure had occurred while I was not there I would probably be talking to my insurance agent regarding fire right now.
PS: Pack being charged at time did have BMS, but my other pack does not have BMS.....this could have been very bad outcome.
v/r,
P