Cells venting on discharge

[minichamps11]

Anyone else experienced this?

Was discharging a pack of new 4600EP's on an Eagle CDC @20amps when the negative end cell started loudly venting. Now I've had old cells vent during charging, but these cells are only 3 charges old & were discharging.....are they screwed?

I take them down to 7.2v on the CDC before using my Novak equaliser to go down to 0.9v per cell.

[Rich D]

20A ?

My LRP Pulsar 3 can only discharge @ 10A max

Could this be anything to do with it ?

[Thomas P]

I Disc on 22A..no went on my cells at all..20A discharge aint much if you compare to what a TC can draw on 5 min..

New cells can do that, wenting..( my SMC IB manual, there was about 200 sec of charging, then tray down to 0.9 per cell..then charge about 5-6A...if the cells starting to went, abort, disch , tray and then reedo it..)

have ya read the manual for the pack?

[Jonathan]

Measure the voltage across each cell when the venting occurs. Could be that one cell has a problem ?

[neiloliver]

venting during discharge is not good. check to see if that cell still has a positive voltage during discharge; it may be that it has been driven negative and is now generating hydrogen gas. I would suggest swapping this cell out.

Neil

[dan_kitty]

i was discharging (10a) a new pack the other day, then one of the cells (end negative cell) made a loud pop noise followed by a fizzing sound. i took it off the charger and the cell continued to fizz for a good few minutes. extenally cell looks ok, checked the voltage on each cell, which was fine apart from the fizzing one. briefly popped the whole pack on charge to regain the voltage., then took it off.


is it safe for me to try and charge the pack up, or should i not risk it?

this was one of my 2008 legal packs so i want to rescue it, or im down to 2 packs for oswestry

ta