BATTERY FIRE

lovemybike

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BATTERY FIRE

Here’s the set up. 1000watt brushless motor. 48 volt. 20ah lithium iron battery pack. 20 inch bike wheels.
A great, powerful, sturdy bike. I love it to bits.
I’ve had the bike for 6 months.
My battery burst into flames yesterday. This was 5 mins after it was parked up, having competed a one mile journey. Last charged 48hrs ago. Not much used since then.
I did managed to remove it before bike destroyed. The battery however was wrecked. First question, what may have caused this?
Have now tried bike on another spare 48 volt battery but no action.
The question therefore is what additional damage did the burnout do and to which components? The motor? The 12 mosfet controller? The throttle?
What do folk recommend I do to unpick this problem?
Ideally, I'd love to have a systematic series of tests that verifies each component as good or as damaged.
I'll then replace accordingly. Are there other postings that address this problem? I haven't been able to find any.
Thanks Simon/Macclesfield/UK.
Please email me with thoughts as well as posting here. simonbridge26@gmail.com
 
Cheap, generic, chinese BMS is what probably did it.

Buy a battery from a reputable seller like Grintech at www.ebikes.ca and not some unknown seller.
Other good sellers are: Unit Pack Power, EM3EV, Luna, OSN Power.
 
The problem is that you bought such a poor battery there apparently isn't a brand or model worth mentioning. Also, battery management and stuff, but a good battery should make that aspect transparent and almost foolproof.

Don't cheap out on batteries. Buy reputable batteries that are professionally engineered from someone in a first world country, not only because third world engineers are less competent but because the companies that employ them aren't as concerned about liability. Good batteries all will use name-brand cells from companies you've heard of like LG Panasonic Sony Samsung etc.

If battery price sounds too good to be true, it is.

Oh also in addition to not burning up good batteries will give you better performance and last longer.

Finally, putting your email on a forum and asking people to contact you personally about anything other people would be interested in, especially a safety issue, defeats the purpose which is so everyone can learn.

Finally finally, there are no guarantees against an ebike fire and you should never bet your life or belongings you can't afford to lose on the bike not catching fire. So charge it somewhere isolated and open, or watch the entire time.

You can get special batteries that are almost impossible to catch on fire, but they weigh twice or more for the same capacity. Lithium iron phospate or LTO is probably the ticket there.
 
You're very lucky it didn't burn down your house. If nothing else got burned, then it should be OK other than the battery.

One problem with battery fires is they destroy the evidence so you will probably never know exactly why it failed. Most likely something shorted, either a wire or between cells. Most fires occur during charging, but I've seen a few that seemed to be triggered by vibration or impact during riding.

I agree you should look for a battery that is better constructed to minimize this risk.
 
Some signs to look for when buying a battery.

- They are vague about the battery

- They do not list what brand of cells they are using, for example Samsung 18650-25R 2500mAh 20A
*I like to see the full title listed as in the example above, even better a fuller description or even a spec sheet

- They do not list the format in which the cells are placed, for example 14S5P

- They over exaggerate the distance you can ride, like stating 36V 5Ah can go 100 miles
*That is way more common, good advertising but complete BS unless its a 100 miles downhill.

- They are selling on eBay, Amazon, Aliexpress, Alibaba without a normal website url

- Their online presence does not show exactly where their basement is, oh sorry I mean "factory" is
*Which is actually quite common. I like to then check out the address on Google Maps and see if its a real store front, a real basement in parents house, apartment, or factory. Sure they could give a bogus address, piggy back their address. Also, remember that Google Maps has old maps, say one street view could be from 2017, but you can also go further back to whatever previous years they have, say in 2015.

- Check out online forums to see if the seller has sold to other people before and see if there are any bad posts
 
It probably put the controller into a suicidal, self destruct mode, but that's just an armchair guess. Could be just about anything, but the controller is between the motor and battery, so........ You can ck the motor easily enough anyway w/o a controller or throttle.

A fire in an expensive battery is possible too, not just in the cheap ones, especially if it has unseen damage or the wrong or faulty charger. Fortunately, my place is adobe brick, so not much is going to burn up if the battery ignites. I'm going to use sealed lead acid batteries on my eTrike project, and may convert the eBike as well.

Even though my place isn't going to go up in flames if the battery does the same, I'm concerned about it being between my legs on the bike and flaming up and maybe exploding.
https://www.youtube.com/watch?v=0NnIjJaQ_gY
 
Any sort of bad wiring causing some type of short.
I saved my 14*6 by building with dime tubes as insulators, tightly wrapped the pack with Kapton tape, insulated under and over each wire run.
The SPS fuked up, the 3rd one, its a cheap knockoff of the original.

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https://endless-sphere.com/forums/viewtopic.php?f=14&t=106924

Take a new pack apart and inspect it, upgrade and insulate if necessary. The packs go through a shit load of vibrations and shock, you can never have too much insulation.
 
We need more info to even guess the cause of the fire.

What battery?
BMS?
Was it Charging?
How was it mounted?
Hard case?
 
No need to guess very much with Lipo

https://endless-sphere.com/forums/viewtopic.php?f=14&t=60169&p=1130932&hilit=lipo+satiator#p1130932

https://endless-sphere.com/forums/viewtopic.php?f=14&t=68896&p=1108547&hilit=lipo+safe#p1108547

https://endless-sphere.com/forums/viewtopic.php?f=2&t=67710&p=1021791&hilit=lipo+safe#p1021791
 
A handy tip for convenience.

Lots of folks have unused fireplaces in their homes. Makes a great place to charge batteries.

I have a cheap charlie China FDM 3d printer, it has a permanent home in my unused fireplace.

Works great for either, even better with glass doors. The glass doors make the printer noise go away mostly.

FIreplace is an excellent spot, and appropriate for the low quality packs.
 
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