Posts: 1489
Joined: 10/7/2004 From: Temecula,
CA, USA Status: offline
Hey all...
We've been doing electrics for a little over a year now. Have quite a collection of various Lipolybatteries, and 4 different chargers. Today, I was charging all our batteries preparing for a day at the flying feild. Plugged in one of my 3S HD 2100 mAH 12C Dymond Modelsports on the Astroflight Model 109 Delux Li-Poly charger. Brought the current setting up from zero to 5 amps and specifically noted it was on a 3C1 (showing my son how it auto-detects the cell count). Left it to charge.
After maybe 8 minutes, hear a pffffssstttt hissing sound, and looked over at the battery laying on the workbench. The battery was all puffed up and swollen.... Holy Crap! I grabbed the lead, unplugged it an tossed it on the floor. Then I grabbed the little cake pan that I ususally put the batteries into and tossed the battery into it, took it outside to let it calm down.
I saw that it was smoking in the pan, and got out the digital camera to get a shot of it. Still hissing like a mad snake, there was a cool thick smoke collecting in the pan.
Posts: 1489
Joined: 10/7/2004 From: Temecula,
CA, USA Status: offline
Well, just after getting that shot, I backed away as the hissing became more violent... then WOOOF! It went off like a bomb, blowing a plume of flame up into the air 5-6 feet high... blasting like a blow-torch. My son, my Father-in-law and I were just watching in shock as if blasted like a booster engine on the space shuttle. I caught my wits, and took another shot as it began to die down.
Posts: 1489
Joined: 10/7/2004 From: Temecula,
CA, USA Status: offline
Trying to figure out what happened... still very concerned about this mishap. This charger auto-detects cell counts, as I said before. Looked at the display after it was all over, and noticed it said 4C2 . Somehow, during the charge, the charger decided to step it up to 4-Cell voltages (15.61 volts according to the display). It didn't show over the mAH that would be expected (1756 mAH), real weird.
Anyway, WARNING to ALL... these things can go off like a bomb. Had we not been sitting there, probably would have burned the garage down. We're buying one of those ceramic lipo charging pots ASAP. This is nothing to mess around with. I can't describe just how violent the flames were at first, like a huge blow-torch.
< Message edited by TManiaci -- 12/27/2005 2:39:27 AM >
Posts: 1489
Joined: 10/7/2004 From: Temecula,
CA, USA Status: offline
The battery was fine before the charge, and has maybe 30 cycles on it, never been crashed. We almost never run them down to LVC, so generally they are only 1/2 to 3/4 discharged after a flight. We've all seen the lipoly burns where they have done it intentionally. Never dreamed it could happen under "normal" conditions.
5 amps into a 2100 pack would scare me anyway! I realise that they are doing 80% charge in 30 min now on some packs but I still wouldn't have set the charger over 2.1 amps. I wouldn't feel safe.
Posts: 3348
Joined: 1/2/2005 From: Pass The Rolls Please,
CA, USA Status: offline
I think I should go buy a fire extinguiser; a c02 one or a foam one?
Glad no one was hurt. I usually charge my li-pos on a brick ontop of something flat inside the engine compartment. Maybe I should build a brick fort or something...
Posts: 166
Joined: 8/26/2002 From: Northridge,
CA, USA Status: offline
Sorry to hit you with the brutal facts, but you caused this by charging at a rate far beyond what is appropriate for Lithium Polymer cells. The important thing for all that read this is that the warning that you receive with the batteries, chargers and almost every product that deal with lithium polymer are real! Thanks for your honesty about the steps that led up to this unfortunate event. Most of the time, guys just post a picture of their garage after the fire and........"they have no idea what happened. Must be them darned Lipos"
I'm glad no one was hurt and really hope others that see this will avoid overcharging!
Posts: 8974
Joined: 3/7/2003 From: LaGrange,
OH, USA Status: offline
I am sorry this happened and thanks for posting the warning. I know it could happen to me. I have a couple of questions though and do not know this charger.
The questions are between post 1 and post 5.
You verified the auto cell count and then did it change? during the charge?
I realise some will blame the 5 amp rate or cell imbalance perhaps but I am wondering how it got from 8 minutes to 22 minutes as 5 amps at 8 minutes is only about 700 mah.?? the display shows 1756 and 22 minutes.
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All Forums >> Radios, Batteries, Clubhouse and more >> Batteries & Chargers >> The Lipo Burn - Pictures! Another WARNING 
The Lipo Burn - Pictures! Another WARNING - 
. Somehow, during the charge, the charger decided to step it up to 4-Cell voltages (15.61 volts according to the display). It didn't show over the mAH that would be expected (1756 mAH), real weird. 
