Poly Battery Blew Up Into Flames Today
- Thread starter Jaffasoft
- Start date
http://www.endless-sphere.com/w/index.php/Fires
Jaffasoft
10 mW
- Joined
- Nov 24, 2010
- Messages
- 27
The reason must have been (with hindsight), the battery was left on the bike at a house for 12 months, previously it was a brand new kit and battery had been charged every time, topped up each night after riding during the day.
Since it not being in use I finally got back to pick up my bike. I was travelling and had to leave it thousands of miles away after my car blow up. Long story.
On charging the battery after this long break between charges, I heard a load thud like explosion and ran to find it all burning.
BMS? well no, but the charger was one that auto cut off when the battery was full. I have also got a little connection thing I could put on it to discharge equalise each cell. I never had to use it once.
More details: I was running a 2000 watt Petrol Generator, running a 240 volt power drill, the Polly 240 volt charger and charging 12 volt batteries from the DC that the same generater puts out.
I have charged this pack with inverters out of car ciggarette lighters before and never had a problem. But the only one thing that has done different here is the battery being left for close a year without being charged and or used at all.
Since it not being in use I finally got back to pick up my bike. I was travelling and had to leave it thousands of miles away after my car blow up. Long story.
On charging the battery after this long break between charges, I heard a load thud like explosion and ran to find it all burning.
BMS? well no, but the charger was one that auto cut off when the battery was full. I have also got a little connection thing I could put on it to discharge equalise each cell. I never had to use it once.
More details: I was running a 2000 watt Petrol Generator, running a 240 volt power drill, the Polly 240 volt charger and charging 12 volt batteries from the DC that the same generater puts out.
I have charged this pack with inverters out of car ciggarette lighters before and never had a problem. But the only one thing that has done different here is the battery being left for close a year without being charged and or used at all.
SamTexas
1 MW
Sorry for your loss. What's a Poly battery? Do you have a picture and/or a link?
Jaffasoft
10 mW
- Joined
- Nov 24, 2010
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- 27
Yep it's a bit sad. Lot of money goes in 
but hell it was fun riding in the breeze.
http://en.wikipedia.org/wiki/Lithium_polymer_battery
but hell it was fun riding in the breeze.http://en.wikipedia.org/wiki/Lithium_polymer_battery
Jaffasoft said:
Did you check the pack or cell voltages at all before charging, after having left it so long without charging?
If not, then we have no way to know for sure, but i would expect one or more cells were below the safe cutoff level, and had become dangerous to charge again, causing a fire once they reached some particular charge level or temperature.
Or just as likely (maybe moreso), one or more cells were much lower in voltage than others, so that probably when you "bulk-charged" the pack with no way for it to sense a cell had gone too high and shut off the charge at that point, it overcharged one or more cells and those cells then started the fire.
The charger can only know to cut off the cells when "full" if there is both a monitoring system on the pack that checks each cell's state of charge (at least by voltage), and also a way for that monitoring system to tell the charger that each cell is full, and also a way for the charger or the monitoring system to charge individual cells that are low back up to match the high ones, or to drain the high ones down to match the low ones, and then continue charging or terminate charging if all are equally full.
If the charger does not have all of that, it can only terminate charge at a preset pack voltage (and/or a preset charge current level), which does not mean the cells are all equally full, and may mean some are too full and others are nowhere near full.
Also, I presume your comment of not having to use the balance plug even once means you did not check them with it either. If you never used the balance plug even to check the cells, how would you even know if you needed to balance them? :?
I presume this is the same battery pack?
http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=30362
I found no decision made here:
http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=23140
so I don't know which stuff you actually went for, or what it might have included or been capable of.
http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=30362
I found no decision made here:
http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=23140
so I don't know which stuff you actually went for, or what it might have included or been capable of.
Jaffasoft said:
What page does it load? It should load a list of links to ES threads discussing battery fires.
Jeremy Harris
100 MW
My guess is the same as AWs. One or more cells died duringthe prolonged period of storage, perhaps due to teh small discharge from the BMS, perhaps due to the pack not having been charged before storage.
Charging is when a defective battery is most likely to go up in flames. In fact I'd say 99% of battery fires happen during charging and are almost always the result of a defective cell or defective charger.
There is a strong moral here, NEVER charge a battery unless you are confident that it doesn't have a defective cell. If you're faced with an uncertain condition battery, like this one after a long period of storage, then before you charge it check each cell with a meter to see if it is still within the range where it will accept a charge. If you find one or more cells that are well below normal cut off voltage, then don't charge the pack, fix the defective cells first.
Charging is when a defective battery is most likely to go up in flames. In fact I'd say 99% of battery fires happen during charging and are almost always the result of a defective cell or defective charger.
There is a strong moral here, NEVER charge a battery unless you are confident that it doesn't have a defective cell. If you're faced with an uncertain condition battery, like this one after a long period of storage, then before you charge it check each cell with a meter to see if it is still within the range where it will accept a charge. If you find one or more cells that are well below normal cut off voltage, then don't charge the pack, fix the defective cells first.
No BMS, according to Jaffasoft (and having an unused balance connector lends credence to that).Jeremy Harris said:
Jaffasoft
10 mW
- Joined
- Nov 24, 2010
- Messages
- 27
I had given the pack a couple of little attempts to charge in the last couple weeks through a 12volt car battery and inverter but the car battery was weak and it did not charge fully. I did this about three other times until today. It was on the 200 watt generater way bout an hour last night.
Yes in hindsight if I'd known better I should have connected the little gadget that came with the system to balance it, had I done that it might have charged.
I can clearly see that it have been one cell that has exploded into a few peaces, the others appear to be victims on the flames.
Yes in hindsight if I'd known better I should have connected the little gadget that came with the system to balance it, had I done that it might have charged.
I can clearly see that it have been one cell that has exploded into a few peaces, the others appear to be victims on the flames.
Jaffasoft
10 mW
- Joined
- Nov 24, 2010
- Messages
- 27
Went with a 2000Watt Kit from Hyena and a custom made 36v, think was 15amp hr pack, because he is here in Australia. Now that it is revealed in fire i can see that it appears to be six cells pack about 2.5 x 2 x 6 inches in size each.amberwolf said:
Jaffasoft
10 mW
- Joined
- Nov 24, 2010
- Messages
- 27
Oh, ok so they're link posts. On first quick look thought it was a bunch of data dribble.
You have put my link on there now! Good to see you're using it as an example. Cause i MUST WARN these things are dangerous, if that was in a house today or someone else's house even worse unattended. That would be "house burnt to the ground". I have charged this thing while driving along if it happened then it could killed me easily by startling you or distracting you and driving off the road. Last week I was charging it in my bed on the Matress in a brand new second hand $10000 Campervan. I wasn't in the Van at the time but still I wouldn't want it to burn down.
When properly monitored and used they're not nearly as dangerous.
If the balance connector is used to at least check the voltages before and during charging, this kind of failure is much less likely to happen.
It is of course still possible for a defect in a cell to cause a fire, regardless of monitoring (automatic or manual).
If the balance connector is used to at least check the voltages before and during charging, this kind of failure is much less likely to happen.
It is of course still possible for a defect in a cell to cause a fire, regardless of monitoring (automatic or manual).
dogman dan
1 PW
Good example of a few things I wouldn't recomend. Thanks for posting about it.
Any chemistry, left for a year, ought to have been looked at closer before charging.
Any chemistry, shouldn't be put on a very flamable surface to charge. Luky you it didn't go off while on the bed.
Any chemistry, left for a year, ought to have been looked at closer before charging.
Any chemistry, shouldn't be put on a very flamable surface to charge. Luky you it didn't go off while on the bed.
Jaffasoft
10 mW
- Joined
- Nov 24, 2010
- Messages
- 27
I'm hearing ya! And copping a wrap over the nuckles! Some big lessons learnt here. I just didn't have much knowledge of this stuff but I'm up to pa now! Least I will put some better preventative measures in place next time.
Notice I said next time it hasn't scared me off the horse I mean bike yet.
It's getting late here I just walked past and slightly moved one of the burnt batteries, it shorted started hissing and away it went again, these things are alive, I stood a good 20 meter back in the dark and it was spraying sparkes like fireworks. Good thing it's all on a big area of dirt. I have got an acre here. All the wires are shorting and reacting on any movement so I'm going to have to be carefull with making sure this thing releases all its energy.
Definitely, kiddies at home DON'T be following my example here. These LiPos are NOT a fool proof system for the layman and or uninitiated and I am the FOOL.
Notice I said next time
it hasn't scared me off the horse I mean bike yet. It's getting late here I just walked past and slightly moved one of the burnt batteries, it shorted started hissing and away it went again, these things are alive, I stood a good 20 meter back in the dark and it was spraying sparkes like fireworks. Good thing it's all on a big area of dirt. I have got an acre here. All the wires are shorting and reacting on any movement so I'm going to have to be carefull with making sure this thing releases all its energy.
Definitely, kiddies at home DON'T be following my example here. These LiPos are NOT a fool proof system for the layman and or uninitiated and I am the FOOL.
SamTexas
1 MW
So what type of lithium battery is it? RC/HobbyKing LiPo/LiCo, RC/Hobbyking LiFePO4, LiMn? And what cell format? Pouch, cylindrical or rectangular?Jaffasoft said:
migueralliart
10 kW
Part of the reasons I charge my pack to 3.85v per cell if I store them. Also checking all cells before a ride or charge with a celllog and disconnect everything that might draw current of a pack for long periods of time.
etriker
100 kW
amberwolf said:When properly monitored and used they're not nearly as dangerous.
If the balance connector is used to at least check the voltages before and during charging, this kind of failure is much less likely to happen.
It is of course still possible for a defect in a cell to cause a fire, regardless of monitoring (automatic or manual).
That is true.
Here is how they should be used.
http://media.hyperion.hk/dn/g3lipo/default.htm
melodious
100 kW
Sorry for your loss.
Here's my opinion. These bikes are meant to be used. Whether you use it once or twice a week for groceries. Or if you use it as your primary means of transportation. Otherwise, it's just a toy. You let it sit for months unattended. Your better off with a regular bike.
Here's my opinion. These bikes are meant to be used. Whether you use it once or twice a week for groceries. Or if you use it as your primary means of transportation. Otherwise, it's just a toy. You let it sit for months unattended. Your better off with a regular bike.
Ykick
1 GW
RC Lipo isn't for everybody....
Hyena
10 GW
Whoa, bummer mate.
I agree with the others, it was likely a cell that went bad or low and resulted in the others being overcharged. Thats a good lesson to others if they leave their packs for a long time. That's the longest I've actually heard of anyone leaving a pack unused.
BMSs are well documented to kill packs (mainly lifepo4) when left unattended for months at a time but in the absence of one it must have just been self discharge. Unless you left the LVC buzzers connected, that'll certainly do it but I always tell people to disconnect those when not in use.
Re: the balancer - I think you were saying that it's not that you weren't checking the balance when in regular use (as instructed) rather that the packs never needed balancing. This is usually the case as these polymer packs are usually quite well behaved.
Did it get wet at any stage ? From memory you left the bike at some random strangers house for a long period of time didn't you ? I'm not suggesting they did anything to it but if it was left laying around in the weather that could be a contributing factor.
Anyway good to hear the experience hasn't deterred you from ebike use. Lithium fires are pretty rare and as I always tell people, petrol is highly explosive too but everyone drives around in a metal container full or that, or leaves it in the garage while sleeping without a second thought. There's usually a good explanation when it does blow up and it sounds like yours was the long period of sitting followed by an attempt to rapidly charge it without checking the balance.
You just woke a guy from a 12 month coma and threw him straight on a treadmill on flat out :lol:
I agree with the others, it was likely a cell that went bad or low and resulted in the others being overcharged. Thats a good lesson to others if they leave their packs for a long time. That's the longest I've actually heard of anyone leaving a pack unused.
BMSs are well documented to kill packs (mainly lifepo4) when left unattended for months at a time but in the absence of one it must have just been self discharge. Unless you left the LVC buzzers connected, that'll certainly do it but I always tell people to disconnect those when not in use.
Re: the balancer - I think you were saying that it's not that you weren't checking the balance when in regular use (as instructed) rather that the packs never needed balancing. This is usually the case as these polymer packs are usually quite well behaved.
Did it get wet at any stage ? From memory you left the bike at some random strangers house for a long period of time didn't you ? I'm not suggesting they did anything to it but if it was left laying around in the weather that could be a contributing factor.
Anyway good to hear the experience hasn't deterred you from ebike use. Lithium fires are pretty rare and as I always tell people, petrol is highly explosive too but everyone drives around in a metal container full or that, or leaves it in the garage while sleeping without a second thought. There's usually a good explanation when it does blow up and it sounds like yours was the long period of sitting followed by an attempt to rapidly charge it without checking the balance.
You just woke a guy from a 12 month coma and threw him straight on a treadmill on flat out :lol:
