Battery a Fire Hazard only when Charging and Discharging?
- Thread starter Samuel
- Start date
Usually, with most, it'd be "safe". But failures of various kinds can happen even "off". There's a post some time back by John in CR describing a hardcase RC LiPo pack that was new, unused, sitting on a desk, that just caught fire for no visible reason.
It's unlikely...but possible.
I don't store any of my RC LiPo or other batteries uncontained in the house or near it. They stay in an old oven outside in the shade between sheds.
Pack mounted on the bikes are in ammocans, vented enough to let out hot gases but hopefully not fire.
Paranoia doesn't hurt, even if it is unnecessary.
It's unlikely...but possible.
I don't store any of my RC LiPo or other batteries uncontained in the house or near it. They stay in an old oven outside in the shade between sheds.
Pack mounted on the bikes are in ammocans, vented enough to let out hot gases but hopefully not fire.
Paranoia doesn't hurt, even if it is unnecessary.
The fingers
10 TW
Trouble is I live in a cold climate, so, if I understand correctly, if I leave them outside they won't last long. I think I'm going to have to build some kind of a fireproof box using cinder blocks, etc... If anyone knows of any easy methods for building fireproof enclosures, please send me the link.
Thank you all kindly for your responses.
Sam
Thank you all kindly for your responses.
Sam
dogman dan
1 PW
My outside storage is an old fridge. Not exactly a fire proof container, but the cells are in metal boxes inside.
The main thing is, it's an insulated box, so they stay above freezing in a mild winter. If your climate is severe, then a reptile cage warmer or something like that can keep it above freezing in there.
Too hot is worse than too cold btw, storing cool is good. But warming it before use is good too.
Lastly, what kind of lithium battery? Some are much more notorious for starting fires than others. All can start a fire, by shorting out wires or metal connecting straps inside.
The main thing is, it's an insulated box, so they stay above freezing in a mild winter. If your climate is severe, then a reptile cage warmer or something like that can keep it above freezing in there.
Too hot is worse than too cold btw, storing cool is good. But warming it before use is good too.
Lastly, what kind of lithium battery? Some are much more notorious for starting fires than others. All can start a fire, by shorting out wires or metal connecting straps inside.
I think it's lithium magnezium, though not certain, got it from: http://calibike.com/?product=electric-bicycle-ebike-48v-15ah-lithium-li-ion-battery-and-charger, but they don't the one I have anymore.
I like the fridge idea, but I don't have the space (live downtown with a puny back yard). Still leaning towards a ammo box sitting inside an array of cinder blocks...
Thanks,
Sam
I like the fridge idea, but I don't have the space (live downtown with a puny back yard). Still leaning towards a ammo box sitting inside an array of cinder blocks...
Thanks,
Sam
Samuel said:
Dunno if any of htem are "easy" but:
http://www.google.com/search?q=building+fireproof+enclosures
and probably more useful:
http://www.google.com/search?q=How+to+build+a+fireproof+enclosure
dogman dan
1 PW
The cali battery is not the type likely to burst into flames. Inside the house, a sturdy metal box, but without seals should help in the rare event something did go wrong. If by some way it started to get all hot, it's not sitting on a pile of newspapers on a wood table, or lying on the carpet. Simple common sense precautions all you need for that battery. Others have used items like flower pots, turkey pans, even just put it inside your oven can work if you can rely on not baking the thing.
Again, it's just common sense, don't put it next to the curtains in the baby room, you know what I mean?
But like I was saying, any battery can short, if wired are damaged by dropping it, letting it rattle too much in a battery box, etc. I had a short burn a pickup truck once, just a bad short on a 12v battery.
So protect your battery with something. I like to make battery wrappers from political signs and tape. It gives some space between a battery box and the battery, and I put a nylon strap carry handle on them. So no dropping the pack. The main danger you have with that battery is if you do something that wrecks it, causing a short, which makes any battery get all hot as it discharges itself crazy fast.
If your yard is too small for an old fridge, which could even be the dorm room/ motel room size, another way to keep the pack warmer in winter would be a simple ice chest. Metal box inside, then the ice chest helps it keep unfroze overnight. In the am, bring it in to warm at least some before you use it.
Again, it's just common sense, don't put it next to the curtains in the baby room, you know what I mean?
But like I was saying, any battery can short, if wired are damaged by dropping it, letting it rattle too much in a battery box, etc. I had a short burn a pickup truck once, just a bad short on a 12v battery.
So protect your battery with something. I like to make battery wrappers from political signs and tape. It gives some space between a battery box and the battery, and I put a nylon strap carry handle on them. So no dropping the pack. The main danger you have with that battery is if you do something that wrecks it, causing a short, which makes any battery get all hot as it discharges itself crazy fast.
If your yard is too small for an old fridge, which could even be the dorm room/ motel room size, another way to keep the pack warmer in winter would be a simple ice chest. Metal box inside, then the ice chest helps it keep unfroze overnight. In the am, bring it in to warm at least some before you use it.
999zip999
100 TW
I have some stored in a barbeque or maybe a big flower pot. It also helps if you use the battery within specs. and don't use a 1,000 watt battery at 1,500 watts ect.
dnmun
1 PW
your battery is not gonna blow up or catch on fire. the risk of fire is from shorts in the wiring and not from your battery being charged or discharged if you have a BMS to protect it. if you have a BMS then it will prevent fires caused by shorts of the output so there is no risk at all in any case.
dogman dan
1 PW
Pretty strongly put, but I tend to agree. His pack is not made from a chemistry prone to burst into flames, and it does have a bms to protect it.
The main risk is doing something along the way that cuts a wire, or crushes a corner causing a short. Then it's sparks that start a fire. Not the battery spontaneously catching fire.
Common sense careful is all he really needs. I would not hesitate to store it inside, but inside a non flammable box of some kind is better than sitting on the carpet. Tool box, flower pot, turkey roaster, etc. Then if it should start to spark, it's not going to spread to the house. And none of that will happen unless you screw up first and damage the pack badly.
But like I said, don't put the box next to the curtains in the baby room.
Use some common sense.
The main risk is doing something along the way that cuts a wire, or crushes a corner causing a short. Then it's sparks that start a fire. Not the battery spontaneously catching fire.
Common sense careful is all he really needs. I would not hesitate to store it inside, but inside a non flammable box of some kind is better than sitting on the carpet. Tool box, flower pot, turkey roaster, etc. Then if it should start to spark, it's not going to spread to the house. And none of that will happen unless you screw up first and damage the pack badly.
But like I said, don't put the box next to the curtains in the baby room.
Use some common sense.dnmun
1 PW
the only pouches i have outside are the 8Ah nanotech lipo that had the hammerhead swelling and high self discharge. put them on the concrete sidewalk outside but under the overhang of the house so not too wet but i should just toss them since they have all split open and the white goop is showing.
Wow, thank you everybody, extremely helpful. I've made a kind of triangle bag and wasn't too concerned that it bumps the frame a lot, but now that I understand battery damage is a big culprit in fires, I will fix that right away. And I should be able to swing a cooler in my back yard with a toolbox in it.
Thank you all kindly, this has taken a load of my mind.
Sam
Thank you all kindly, this has taken a load of my mind.
Sam
dnmun
1 PW
no, battery damage does not cause fires. you do not need to put your batteries in a cooler. fires are caused by shorts in the wiring and when there is no BMS to turn off the current flow then the short causes the wires to overheat and catch the plastic bag around the battery on fire. you can look up chroot's headway pack fire which is the only fire we have had besides greg's fire which was caused by the balancing charger overcharging the one cell in the pack. there have not been any other fires reported. floont burned down his house by charging lipo with no BMS using the big meanwell power supplies but he never discussed it here.
dogman dan
1 PW
Damage that actually causes a short in the wiring is what I was talking about. Shorts, sparks, fire. Different from a cell thermal runaway, but it can ignite anything nearby. So I think wrapping your battery in some extra, protective material is wise. Dnmun likes to use Masonite, but lots of other materials are good. Adding a carry handle can prevent dropping it, which is not likely to start a fire, but it is likely to cause other problems that cost you money to fix.
I see no need whatsoever to keep it in the yard. But inside a fire resistant box, just in case of an accidental problem with the wiring on the pack is not a bad idea.
I see no need whatsoever to keep it in the yard. But inside a fire resistant box, just in case of an accidental problem with the wiring on the pack is not a bad idea.
dnmun
1 PW
it is wise to protect the pack from damage. i did not mean that dents or perforations of the pouches are not damaging, but the sources of fire are from shorts in the wiring which is unfused so the wires can overheat, and from the loss of control during charging when one cell can be overcharged to the point where it overheats and goes into thermal runaway. this is why the little RC charger or a BMS with bulk charger is needed to charge lipo to be safe.
that is what happened to chroot, his positive charging lead shorted out the battery to wires inside his BMS and that shorted wire caught the nylon bag on fire. his pack was all headway cans.
if your pouch is damaged enuff to short the electrodes together then they will short out internally in some cases but the most common failure mode is just self discharging at high rates until there is no voltage left on the pouch.
there is a thread just recently of a guy who lost one pouch in his HK pack to an internal short it appears. since he did not find the sense wires were shorted the short would have been internal, in the corners where the pack is most highly contorted by the swelling imo.
that is what happened to chroot, his positive charging lead shorted out the battery to wires inside his BMS and that shorted wire caught the nylon bag on fire. his pack was all headway cans.
if your pouch is damaged enuff to short the electrodes together then they will short out internally in some cases but the most common failure mode is just self discharging at high rates until there is no voltage left on the pouch.
there is a thread just recently of a guy who lost one pouch in his HK pack to an internal short it appears. since he did not find the sense wires were shorted the short would have been internal, in the corners where the pack is most highly contorted by the swelling imo.
I had a multistar lipo go bang fizz in the shed while I was out. It hadnt been touched for weeks at storage voltage but was supplied with a low/self discharging cell. It was slightly damp and my mum was in there. She swears she never touched it lol. But no flames. Had it been near paper or source of ignition who knows. Why risk it if you can make other arrangements.
999zip999
100 TW
I bought used Makita packs order 35, but only had 23. But by magic had found 12 more out back to make the sale. They arrived with 12 low voltage packs ???
I saw 5 or more cells shoot fire out the top.
350 cells some water damage. Remember used returned Makita tool packs. Garage fire not on charger, not charged ready for recycling just hadn't done it.
Profit first. Fire second. Don't use used cells unless stored in bbq.
I saw 5 or more cells shoot fire out the top.
350 cells some water damage. Remember used returned Makita tool packs. Garage fire not on charger, not charged ready for recycling just hadn't done it.
Profit first. Fire second. Don't use used cells unless stored in bbq.
I've been using rc Lipo packs for a very long time prior to eBikes and have treated them pretty harshly with high discharge and high g force crashes. I used them in RC 1/8th scale on-road cars, buggies and rc boats. No fuses. Had esc's short out and go up in flames. The treatment we put them through was pretty severe. In one of my onroad cars I ran off the track at full speed, the car decelerated in an instant when it hit a crash barrier, one cell crushed it's tip and failed with no explosions or combustion. There were plenty more dead cells over the course of about 8 years. Shorted out balance plugs tend to burn the pins or wire like a fuse. I had a NiMH aa cell short out once and damn that thing burnt like firecracker for a solid 3 minutes. It was intense. I imagine worst scenario for Lipo would be something similar so I always store them in a charging bag because that's handy but I'm not really fearful of them spontaneously combusting. Keep your wires in good condition. Box them and strap them down during usage so that they cannot be pierced or crushed or shorted. Use fuses and be smart. Charge them outside or away from combustibles if you want to be safe but just be around when they're on charge, if you gotta go out just pause the charge, it's not hard, just use common sense. Lipos can generally be charged in one hour so that's not a long time. Lipos have got a bit of a bad reputation for being unsafe when it's not exactly fair. They get abused pretty badly in RC applications by millions of users worldwide so there's more anecdotal evidence of fires and accidents. In my opinion a lot of that can be attributed to user ignorance, crashes and poor wiring.
999zip999
100 TW
What I don't understand is why a successful ebike company pendago have battery fires and recall and then you don't hear that many battery fires of victpower or cammy batteries. Most people fill ashamed I don't talk about their battery fires.
amberwolf said:
Exactly. MOST of the instances of failure happen during use (charge/discharge) or after immediate mechanical or environmental exposures, but there have also been many cases where lithium batteries appear to have caught fire for absolutely no reason, when sitting idle not being charged, discharged, or subject to any external forces. I've been party to 2 instances of this happening firsthand, once in someone's bedroom room here in Vancouver (he was lucky to be home and just waking up when the pack started to confalgrate and able to drag it outside before it turned into a fireball), and in another case one of our suppliers had a battery inside a pallet in their warehouse just go into spontaneous combustion. Both of these situations were with ebike grade ~10Ah LiPo cells.
We also had one of our own customers with a brand new 18650 based pack with samsung 22P cells, sitting in the cab of his truck neither charging nor discharging, which spontanously overnight went into a meltdown and completely filled the insides of his vehicle with smoke and soot, although there was no evidence of flames and fire. In that case as far as we could tell it appeared to have an electrical bms/wiring origin rather than a cell origin, but puts you on edge just the same.
So yes, sitting there, not charging, not discharging, not visibly doing anything, lithium packs can and have gone catastrophic, and if you're in this industry long enough it will come alarming close and personal, not just anecdotal. That's why I get a bit annoyed to see so many people on ES immediately jump to the safety defense of lithium (especially lipo) batteries and claim issues are always the result of user error. Just because you yourself haven't so far had any problems with your giant collection of hobby packs and carefully balance and baby them, doesn't mean that you'll always be so lucky.
My own feeling on the relative safety with 18650 packs is that's it's probably better than most consumer plug-in appliances at this stage. I've had CF lightbulbs from home depot melt down and drip molten glass on the floor, toasters that don't pop up and cook crumbs into smoke etc. But I still often leave the lights on when I'm not around the house, and I'll similarly leave an 18650 pack charging on the floor when I'm not around, as IMO are at similar risks of causing an incident. Others are sure to turn off everything plugged in the wall before they leave the house, and would never let a battery charge unattended, and I wouldn't fault them at all for having an abundance of caution either.
999zip999 said:
Do you think Cammy or Victpower would issue a massive public recall if one of their customers experienced a battery incident? Even if 10 or 50 customers had incidents? I don't think anyone would hear about it. There is such a night and day difference in responsibility and liability between what we expect from a reputable western based company vs what we tolerate from a china exporter.
Hillhater
100 TW
As best I can recall, all the reported lipo fires have occurred in multi cell packs, not in single cell units.
Now obviously, single cell use is not common for our aplications , so that in itself proves nothing......except that all packs have by definition multiple interconnects, wires, joins, etc etc, and a lot of human interference !
Even the A123 20Ahr pouches which were known to be made with internal defects, did not prove to be fire bombs !
I just suspect that the weight of evidence suggests that lipo pack fires are not initiated by internal cell faults, but by external "pack related" issues like poor assembly, bad connections, wiring shorts, BMS failures, physical damage, over charging, etc etc.
Many of these factors will be agrivated during charge/discharge, so to that extent I agree with the thread title, and also still accept that lipo packs should be respected and treated in a similar way to having a potentially leaky gas can in your house !...IE:, store them outside the house !
Now obviously, single cell use is not common for our aplications , so that in itself proves nothing......except that all packs have by definition multiple interconnects, wires, joins, etc etc, and a lot of human interference !
Even the A123 20Ahr pouches which were known to be made with internal defects, did not prove to be fire bombs !
I just suspect that the weight of evidence suggests that lipo pack fires are not initiated by internal cell faults, but by external "pack related" issues like poor assembly, bad connections, wiring shorts, BMS failures, physical damage, over charging, etc etc.
Many of these factors will be agrivated during charge/discharge, so to that extent I agree with the thread title, and also still accept that lipo packs should be respected and treated in a similar way to having a potentially leaky gas can in your house !...IE:, store them outside the house !
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