Hissing Cells

[chris burgess]

Bought some cells, 3700 Nosrams. As it happens they were Frank Noels, but that by the by.

Brand New, unused, not even built. Built 'em up, charged 'em up and one of the cells vented.......how impressed am I?

Any idea what caused it? None of them got particularly hot whilst soldering them up, I have a good iron etc., and have built up lots of packs without this ever happening.

Charged them on the Protrak, at the default setting and it was busy chucking in the mah, and on the stroke of 50minutes worth of charge (about 4300mah according to the charger) one went fizz.

I presume that cell is now goosed?

If I drop the delta volts on the protrak to say 4 0r 5 instead of 6, will I still get a full charge, and will this prevent the cells from going pop?

I am thinkning that it was just a duff cell, as none of my other packs have ever gone fizzzz fizzzz fizzz fizzz fizz fizz fiz fiz before.

[Northy]

It might not affect them. Did gas escape or any electrolyte (think I spelt it right)?

[chris burgess]

as far as I know, only gas escaped, there was nothing wet or sticky on the outside of the cell.

I am going to hook them upto the pro-trak with the remote leads to see whats going on.

[bigboss]

Like northy said, it may not effect the performance at all.
Had that happen to a brand new pack of GP3300 on the first charge after soldering it up, so far no ill effects.
I got a fright when it happened to me, I thought it meant the cell was dead now it had vented, but after reading a few treads on the subject it isn't that uncommon apparently IB cells do it quite often(according to the forum I was at), usually with no long lasting effects.
According to the US distributer of IB cells (Intellect) who graces that forum it has to do with a chemical imbalance with in the cell when produced.
That creates excess pressure which will cause the cell to vent under charge.usually though it will vent once and stop (i.e. shouldn't vent during the next charge).
hope this helps Chris.
Cliff

[chris burgess]

Thanks Cliff and Northy...I am going to charge them again tonight and see what happens...

preparing the Personal Protective Equipment just as we speak, having organised an exclusion zone around the cells!

[Northy]

Pressure increases exponentially (is that spelt right?) with the amount of charge you put in, so if you put a little less in , i.e. a lower delta, you'll be a bit safer.

Do you need 3700's? I'm still using 3300's.

[chris burgess]

don't need 37's at all, but they were a good price!