Battery Fire! What’s the latest News, Thoughts and Prevention

zipur

Active Member
Region
USA
E-Bike Fires
I came across this link from last year. This made me think, “I should think carefully about charging”. I guess, one good practice is to buy from reputable manufacturers, not a China Knock Off. And the the obvious, inspect for frayed wires on bike and charger. Try not to drop the battery causing internal damages.
Knowledge is power (Punn), what strategy do you follow to keep your bike from burning down the house.

 
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tomjasz

Well-Known Member
Region
USA
City
Minnesnowta
I charge in large ammo can with rubber grommets preventing wire damage and the gasket removed with lid latched.

Pictured with 2 20Ah triangle batteries.
ammo.jpg
 

Mr. Coffee

Well-Known Member
Region
USA
City
A Demented Corner of the North Cascades
This has been covered a lot here. Short answer is that battery fires seem to have three major causes:
  1. Damaged batteries
  2. Batteries modified by DIYers or operated out of spec
  3. Cheap batteries with poor quality control
So my advice is:
  1. If you drop a battery or have a serious wreck on your bike dispose of your batteries and purchase new ones
  2. Don't mess with batteries or the electronics on your bike unless you damned well know what you are doing, and even then do so very carefully.
  3. Spend the money and buy decent batteries from reputable manufacturers. I expect that bike manufacturers will do their own quality control on the cells before assembling a battery pack.
  4. Be mindful of where you charge. I've charged in a lot of places that were suboptimal but I am very fussy about the conditions of the battery (see above).
Think of it this way: that 500wh battery pack has the stored energy equivalent of about two sticks of dynamite. And in most bikes it is inches from your crotch.
 

PedalUma

Well-Known Member
Region
USA
City
Petaluma, CA
When charging I use a heavy rubber mat to lay the battery on and put the charger on a non-flammable heatsink.
 

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zipur

Active Member
Region
USA
This has been covered a lot here. Short answer is that battery fires seem to have three major causes:
  1. Damaged batteries
  2. Batteries modified by DIYers or operated out of spec
  3. Cheap batteries with poor quality control
So my advice is:
  1. If you drop a battery or have a serious wreck on your bike dispose of your batteries and purchase new ones
  2. Don't mess with batteries or the electronics on your bike unless you damned well know what you are doing, and even then do so very carefully.
  3. Spend the money and buy decent batteries from reputable manufacturers. I expect that bike manufacturers will do their own quality control on the cells before assembling a battery pack.
  4. Be mindful of where you charge. I've charged in a lot of places that were suboptimal but I am very fussy about the conditions of the battery (see above).
Think of it this way: that 500wh battery pack has the stored energy equivalent of about two sticks of dynamite. And in most bikes it is inches from your crotch.
Thanks good info for us newbies, I’ll search better next time.
 

indianajo

Well-Known Member
I charge outside.
I hung the battery off the front of my bike, instead of 6" from my crotch. Balances the bike better out there too, with groceries in the back.
I tried to buy a LiFePo4 battery that is less flammable, but both btrbattery of amazon & sun-ebike baldwin city CA warehouse were selling garbage, instead of batteries. Neither would produce more than 2 A before the voltage collapsed.
 

6zfshdb

Well-Known Member
Region
USA
City
Northeast Pennsylvania
In addition to charging in an open area with no flammables nearby, I use only batteries constructed with "quality" cells.
These batteries are heavy, awkward to carry and easily damaged. They are also expensive so I store and transport mine in rugged cases such as these padded models:
P1070664a.jpg P1070667a.jpg

 

m@Robertson

Well-Known Member
Region
USA
Great topic. Not enough attention gets paid to this.

Can't emphasize enough how important it is to buy a battery from a seller who has a known, sterling reputation in the marketplace. Lots of references available even if those are only from word-of-mouth across the online community. It drives me insane when I see people asking about buying cheap Chinese packs from small vendors who have absolutely zero accountability for their product's performance or safety. Even a 'spotty' reputation (looking at you: UPP) isn't good enough when it comes to the potential for consequences.

Some more stuff on charging:

1. I use a charger every day. Usually all day long at work and again on my return home. Used that frequently, cheap chargers tend die younger. I have had no less than three of the more expensive variety that lets you dial back amperage and charge percentage... fail to stop charging (it kept going). I caught one 52v battery where the charger - which was set to 80% - was reading 59v and climbing. That was the last time I trusted even that better grade of adjustable charger.

The ones that don't fail are all potted/fanless units that are not cheap to start with. That can be a $300 Cycle Satiator (I have one) or a much more reasonably priced LED power supply - a device that is essentially a Satiator, without the GUI. These units are rated for years of outdoor use, typically with MTBFs in the hundreds of thousands of hours. I have never had a single failure from this kind of charger. This is not something I figured out myself. They are a common thing in the DIY ebike community.


2. Charge SLOW. Really slow. If something goes wrong it takes longer for things to go bad, and the chargers stay cool since they are only sipping power. The chargers I use are adjustable and typically bottom out at 0.85a. I like to leave them there (but they can be dialed up if time is of the essence). I also have a couple of laboratory power supplies that are more easily adjustable and I run them at 0.20 amps often as not, where they are only eating about 11w. A nice slow charge rate is better for the battery too.
PXL_20210215_025251320.jpg
PXL_20210223_172616305.jpg


3. Know your volts-per-hour charge rate. As in: "on this battery I get an additional 1 volt per hour" or somesuch. It just takes a countdown alarm set for an hour to figure it out. On my adjustable chargers I set them to an even 1.0a and then I can use whatever number comes up for a quickee calculation on my phone that will figure out what rate I need to get charged in the time I have available.

4. Knowing 3. sets you up for this: Maybe the most important thing of all to add to your charging protocol... A mechanical (!) cutoff timer.

Knowing the volts/hour you are adding in, you can set the timer so it cuts off before anything can go wrong. If your layers of protection are the charger cutting off at the right voltage, and the BMS cutting off the current to the cells if the charger doesn't stop when it should, a physical, mechanical timed shutdown is another fail-safe layer to the onion.

Best $9.99 you will ever spend:


61KgD31CEnL._SL1500_[1].jpg
 

Ravi Kempaiah

Well-Known Member
Region
Canada
City
Halifax

m@Robertson

Well-Known Member
Region
USA
Trying to tell people not to skimp and to never even think about that battery from a Chinese company that cannot be held accountable seems to be an upstream swim. People just want to save money and don't believe that the $299 Chinese Special will bite them. For me, with antennae spread out over several internet groups, I see soooo many failures - not just the fires but the undercapacities and the customer service that goes dark once the seller gets busted - I NEVER have cause to regret staying miles away from a cheapass battery.
 

PedalUma

Well-Known Member
Region
USA
City
Petaluma, CA
Trying to tell people not to skimp and to never even think about that battery from a Chinese company that cannot be held accountable seems to be an upstream swim. People just want to save money and don't believe that the $299 Chinese Special will bite them. For me, with antennae spread out over several internet groups, I see soooo many failures - not just the fires but the undercapacities and the customer service that goes dark once the seller gets busted - I NEVER have cause to regret staying miles away from a cheapass battery.
Last year I assembled a $599 electric bike for a single mom who didn't know better. All I could do is give all the warnings. The BMS was minimal and located inside the display. The bike had to go on a Christmas tree timer to prevent overcharge. It was a Walmart folder with a HB bag battery. I hope she is okay. It seams like playing Russian roulette.
 

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m@Robertson

Well-Known Member
Region
USA
Last year I assembled a $599 electric bike for a single mom who didn't know better. All I could do is give all the warnings. The BMS was minimal and located inside the display. The bike had to go on a Christmas tree timer to prevent overcharge. It was a Walmart folder with a HB bag battery. I hope she is okay. It seams like playing Russian roulette.
An all too common story.

My fire prevention strategy in one sentence:

NEVER look for a cheap battery deal.
 

bexamous

Active Member
Region
USA
Last year I assembled a $599 electric bike for a single mom who didn't know better. All I could do is give all the warnings. The BMS was minimal and located inside the display. The bike had to go on a Christmas tree timer to prevent overcharge. It was a Walmart folder with a HB bag battery. I hope she is okay. It seams like playing Russian roulette.
That display is KD26E, it's not doing BMS.
 

Ravi Kempaiah

Well-Known Member
Region
Canada
City
Halifax
Great topic. Not enough attention gets paid to this.

Can't emphasize enough how important it is to buy a battery from a seller who has a known, sterling reputation in the marketplace. Lots of references available even if those are only from word-of-mouth across the online community. It drives me insane when I see people asking about buying cheap Chinese packs from small vendors who have absolutely zero accountability for their product's performance or safety. Even a 'spotty' reputation (looking at you: UPP) isn't good enough when it comes to the potential for consequences.

Some more stuff on charging:

1. I use a charger every day. Usually all day long at work and again on my return home. Used that frequently, cheap chargers tend die younger. I have had no less than three of the more expensive variety that lets you dial back amperage and charge percentage... fail to stop charging (it kept going). I caught one 52v battery where the charger - which was set to 80% - was reading 59v and climbing. That was the last time I trusted even that better grade of adjustable charger.

The ones that don't fail are all potted/fanless units that are not cheap to start with. That can be a $300 Cycle Satiator (I have one) or a much more reasonably priced LED power supply - a device that is essentially a Satiator, without the GUI. These units are rated for years of outdoor use, typically with MTBFs in the hundreds of thousands of hours. I have never had a single failure from this kind of charger. This is not something I figured out myself. They are a common thing in the DIY ebike community.


2. Charge SLOW. Really slow. If something goes wrong it takes longer for things to go bad, and the chargers stay cool since they are only sipping power. The chargers I use are adjustable and typically bottom out at 0.85a. I like to leave them there (but they can be dialed up if time is of the essence). I also have a couple of laboratory power supplies that are more easily adjustable and I run them at 0.20 amps often as not, where they are only eating about 11w. A nice slow charge rate is better for the battery too.
View attachment 89410View attachment 89411

3. Know your volts-per-hour charge rate. As in: "on this battery I get an additional 1 volt per hour" or somesuch. It just takes a countdown alarm set for an hour to figure it out. On my adjustable chargers I set them to an even 1.0a and then I can use whatever number comes up for a quickee calculation on my phone that will figure out what rate I need to get charged in the time I have available.

4. Knowing 3. sets you up for this: Maybe the most important thing of all to add to your charging protocol... A mechanical (!) cutoff timer.

Knowing the volts/hour you are adding in, you can set the timer so it cuts off before anything can go wrong. If your layers of protection are the charger cutting off at the right voltage, and the BMS cutting off the current to the cells if the charger doesn't stop when it should, a physical, mechanical timed shutdown is another fail-safe layer to the onion.

Best $9.99 you will ever spend:


View attachment 89428

Thanks for sharing your knowledge.
I enjoy reading quality posts from people like yourself.
 

Ravi Kempaiah

Well-Known Member
Region
Canada
City
Halifax
One more recent incident.
It is important customers pay extra attention when they purchase an E-bike battery.

 

BrianK

Well-Known Member
Simple idea - what about charging the battery inside an oven (not in use and no pilot light, of course)? I realize it would not contain smoke and toxic fumes. But would the average oven contain a fire that could erupt in an e bike battery?
 

fooferdoggie

Well-Known Member
Simple idea - what about charging the battery inside an oven (not in use and no pilot light, of course)? I realize it would not contain smoke and toxic fumes. But would the average oven contain a fire that could erupt in an e bike battery?
and if you forget a battery is in there and turn on the oven even more fun.
 

BrianK

Well-Known Member
and if you forget a battery is in there and turn on the oven even more fun.
I don’t use my oven much. When I do, I have to manually light a propane pilot light, which I physically couldn’t do if a battery was in it.

So in that situation, would a typical oven contain a battery fire?

I’m on limited income and bought a UPP shrink wrapped 20ah 48v battery. Now I’m questioning whether I should even use it.