batteries exploding

[Lowie]

I'm rather new in RC and got a bit curious when I read about exploding batteries in the report of the 2007 World Championship, day seven (http://www.oople.com/rc/photos/worldchampionships-2007/day7/).
How can this happen? And... why can this happens twice in one chamionship? I have seen some competitions, but never an element exploding. Does it has anything to do with the way these top-drivers use, load ... their batteries?

[JCJC]

Extensive thread on racechat a while ago:

http://www.rcracechat.com/vb/showthread.php?t=27232

Mostly cells charged at high amps in an effort to get high output or something.

[lazerboy]

more like an effort to charge the cells fast! LOL this will actually severely overheat your batteries. And, because a battery is a metal tube filled with acid, it's sorta like a bomb. Mostly if batteries explode they are older lipo batteries.

http://static.rcgroups.com/forums/attachments/4/3/5/6/t170959-67-thumb-liposetup2.jpg

http://static.rcgroups.com/forums/attachments/4/3/5/6/t122667-93-thumb-lipofire%20smoke.jpg (http://static.rcgroups.com/forums/attachments/4/3/5/6/t122667-93-thumb-lipofire%20smoke.jpg)

http://static.rcgroups.com/forums/attachments/4/3/5/6/a122668-25-lipofire%20ignition1.jpg



(http://rchomepage.com/%7Edna/LipoFire.wmv)

[DCM]

Batteries will explode for a number of reasons, over-charging, bad soldering or just a flaky cell. The incidences will get higher as the cell power gets higher, in effect, any cell is a little explosion waiting to happen.

[mark christopher]

more like an effort to charge the cells fast! LOL this will actually severely overheat your batteries. And, because a battery is a metal tube filled with acid, it's sorta like a bomb. Mostly if batteries explode they are older lipo batteries.

http://static.rcgroups.com/forums/attachments/4/3/5/6/t170959-67-thumb-liposetup2.jpg

http://static.rcgroups.com/forums/attachments/4/3/5/6/t122667-93-thumb-lipofire%20smoke.jpg

http://static.rcgroups.com/forums/attachments/4/3/5/6/a122668-25-lipofire%20ignition1.jpg



(http://rchomepage.com/%7Edna/LipoFire.wmv)
nah more nimh going bang than lipo

[terry.sc]

Mostly if batteries explode they are older lipo batteries.
http://static.rcgroups.com/forums/attachments/4/3/5/6/t170959-67-thumb-liposetup2.jpg

http://static.rcgroups.com/forums/attachments/4/3/5/6/t122667-93-thumb-lipofire%20smoke.jpg

http://static.rcgroups.com/forums/attachments/4/3/5/6/a122668-25-lipofire%20ignition1.jpg
(http://rchomepage.com/%7Edna/LipoFire.wmv)Those pictures just show what happens if you deliberately abuse a damaged LiPo pack, just like the videos on YouTube. Under normal use with a LiPo specific charger this will never happen. Also none of the LiPos explode, they just vent and catch fire. NiMhs, or more specifically IB4200s, really do explode properly and Jimmys photo of the damage caused to the Academy shows how damaging it is. This cell wasn't on charge, just sitting in the car.

It isn't just specific to modern NiMhs either, I remember an exploding 1400 nicad. IB4200s are at the limit of the technology which is why they are more susceptible to exploding. The Racechat thread covers everything, but remember the experiences there are from competitive racers who try to get the best performance possible from them. If you aren't using IB4200s, nor abusing the batteries like racers do then there is very little risk of you ever seeing an exploding battery.

[lazerboy]

this one was just over charged, but it was a lipo charger.

[Chris Doughty]

check out Jimmys report on day6 of the worlds.

a Nimh expoloded in a car while walking to praccy, BIG mess, bend centre shaft and it split the CF battery strap in half!

EDIT - seems thats what this thread is all about...

[bigred5765]

everyone i have been able to speak to that has had a cell go bang hasn't balanced them before they charged them,yes mark i know your going to say i haven't spoken to everyone thats posted, thats had a cell go bang, but all i have had the same answer balancing my cells how do u mean, or no not time,
if you don't equalise or balance your cells before you charge them, then one cell will over charge and go bang eventually,