Not really sure what board I need but we'll start here...

[NomoneyNohoney]

My son has an electric bike, which he parks and charges in the passageway inside the front door. Having seen some videos of Chinese cars gong up in flames, it occurs to me that I could perhaps take some defensive measures in case his battery pack goes up in flames.

I think it would be overkill (no pun intended) to get a foam fire extinguisher, instead I'm thinking a fire blanket might be enough, as the battery pack is approximately slung under the cross bar, so a blanket would hang well and might do the trick for covering a small bike battery compared with that powering a car. Economic ones are about 1 metre square, which might be ok. I think I'll also fit a fire alarm above, to get a quick warning out.

Anyone got any comments or experience of such happenings? Am I being over-dramatic, or prudent?
(Not an April Fools joke, for ending any doubt.)

[BullDog]

Maybe I'm mistaken. But I recall these are chemical fires and cannot be extinguished by conventional means. Essentially, they are allowed to burn themselves out?

[Lootman]

My son has an electric bike, which he parks and charges in the passageway inside the front door. Having seen some videos of Chinese cars gong up in flames, it occurs to me that I could perhaps take some defensive measures in case his battery pack goes up in flames.

Those remedies won't help if you are not home at the time of the conflagration.

Do you not have a side passageway with a gate, enabling him to park it in the rear yard or garden, a safe distance from the house? Or if terraced, is there a rear gate as there often is? I just would not want that in my house at all.

[Dod101]

I would have thought that a fire extinguisher was supposed to be installed there anyway, but it will not cost much to get one so I would have that as a priority. Then think about the other issues.
Dod
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[jfgw]

You can get fire extinguishers specifically for lithium battery fires. I suspect that very few people bother for a bike though.


Julian F. G. W.

[servodude]

Start by not having a cheap battery - a decent one will provide info on state (charge, balancing, temp, cycles) which should be used to control charging
After that don't use a cheap charger - if it's just supplying current to the battery it isn't checking temperature or charge point

Even if your charger is "smart" don't run it for longer than it needs
If you can't do that easily by being there use a timer in the power socket

Keep the charging port clean - if the comms can't get through it's no longer a smart charger, if the contacts are not good then it can be a literal hot spot as the resistance there is higher than it should be

Keep everything in good condition - don't use stuff if there's fraying etc

A fire blanket would be fine for slinging over the top tube and moving the bike outside - I'd have a plan in place for doing that
And for keeping any flamable stuff away from the bike

And remember that it is probably not going to happen

[Cornytiv34]

If the bike does catch fire do you still have a safe route out of the house. Stairs could be blocked and no way to rear door for escape from fumes or fire.
Mike

[bungeejumper]

Hallelujah to everything that's been said so far. As small-time landlords, we have to figure out what we'll say to our tenants when they decide to park their cheapo e-scooters in hallways and fire escapes. (A problem which is already current for pushbikes, although the risk there is obviously different.) I'm sure the pressure for indoor storage is a lot worse in cities than in our small market town?

A side issue, I know, but the same lithium batteries are used in many mobility scooters, which don't have a particularly bad reputation for catching fire. But which are widely stored and charged indoors, for obvious reasons. Part of the difference might be that the mobility scooters are built to certified standards, instead of being built down to a price like e-scooters and cheaper e-bikes?

Some guidance from Avon and Somerset fire brigade at https://www.dsfire.gov.uk/safety/busine ... heelchairs . We've just spent an eye-watering sum on a state-of-the-art integrated fire alarm system for our rentals. But the best solution would be if people just stopped buying ultra-cheap batteries made from dodgy ingredients.

Harrumph, I'm well wide of the OP's topic. Sorreeeeee!

BJ

[NomoneyNohoney]

Thanks for your suggestions and comments. We do have ways out of the property, but without being able to test, i was hoping that a fire blanket would inhibit any fire, allowing access to open the front door and fling the bike into the street!

I firmly believe that trying to stay one jump ahead of problems is the best way to be, so on my risk/cost benefits scale, a smoke alarm and fire blanket ought to suffice. I'm not paranoid enough for a direct auto-dial link to the fire - station, and a CO2 suppression system or suchlike! A blanket could be used for other fire problems as well.

I really hope all this is unwarranted but you never know...

Thanks all.

[Mike4]

As I understand it there are lots of types of lithium batteries, presenting widely varying fire risks so it might be worth finding out exactly what chemistry yours are. LiFePO4 lithium batteries are widely thought of as the safest and least likely to catch fire. I believe the most common cause of fires is over-charging. If there is one thing LiFePO4 batteries DON'T like, its float charging when already fully charged so I suggest you disconnect it from the charger once fully charged.

The bad thing is as previously said, a lithium battery on fire produces its own oxygen so to put one out you ether have to remove the fuel or remove the heat. Fiendishly difficult to do either so most are just left to burn out in a (hopefully) controlled manner.

IANAE.

[9873210]

Better yet get a proper smart charger designed to support the chemistry (and other properties) of the battery you are using. Turning off the floating charge mode for cells that don't tolerate floating charge is one of the things that smart chargers are supposed to do. This should be much more reliable than remembering to unplug it before you go to bed.

When lithium cells first came out the suppliers would not sell them to us until we'd proved we knew how to protect them and promised we would assemble them into batteries with proper protective circuits before we did anything else. The data sheets made numerous references to energetic self-disassembly and there was a video that prompted discussion of the difference between an actual explosion and merely getting very hot and gassy very fast. There was a test and declarations signed in bloodink.

[Mike4]

Better yet get a proper smart charger designed to support the chemistry (and other properties) of the battery you are using. Turning off the floating charge mode for cells that don't tolerate floating charge is one of the things that smart chargers are supposed to do. This should be much more reliable than remembering to unplug it before you go to bed.
.

Yes I'd expect any electric bike to come with its own dedicated charger that turns the charge off when the upper "knee" is detected. But can you always rely on all of them to always do that? Your faith in modern electronics never going wrong is rather touching!

[9873210]

Better yet get a proper smart charger designed to support the chemistry (and other properties) of the battery you are using. Turning off the floating charge mode for cells that don't tolerate floating charge is one of the things that smart chargers are supposed to do. This should be much more reliable than remembering to unplug it before you go to bed.
.

Yes I'd expect any electric bike to come with its own dedicated charger that turns the charge off when the upper "knee" is detected. But can you always rely on all of them to always do that? Your faith in modern electronics never going wrong is rather touching!

I don't rely on all of them, just the good ones from reliable companies. Far more reliable than depending on humans to implement folklore.

One of the problems is the proper treatment of batteries depends on the battery. Went from flooded lead-acid, to absorbed mat lead-acid, to nicad, to nickel metal hydride, to about three types of lithium. Each of these requires different treatment and some of the things that are good for one are dangerous on others. Customer support and field service spent a lot of time trying to get people to change what they did depending on the battery type. Manuals don't help, placards don't help, cattle prods are illegal.

Much easier once we got proper smart chargers and the rule for everything is plug it in and leave it alone.

[servodude]

Yes I'd expect any electric bike to come with its own dedicated charger that turns the charge off when the upper "knee" is detected. But can you always rely on all of them to always do that? Your faith in modern electronics never going wrong is rather touching!

I don't rely on all of them, just the good ones from reliable companies. Far more reliable than depending on humans to implement folklore.

One of the problems is the proper treatment of batteries depends on the battery. Went from flooded lead-acid, to absorbed mat lead-acid, to nicad, to nickel metal hydride, to about three types of lithium. Each of these requires different treatment and some of the things that are good for one are dangerous on others. Customer support and field service spent a lot of time trying to get people to change what they did depending on the battery type. Manuals don't help, placards don't help, cattle prods are illegal.

Much easier once we got proper smart chargers and the rule for everything is plug it in and leave it alone.

Indeed, and that works until someone messes up and you get a battery that isn't reporting correctly (dodgy cell contact or compromising the thermometer) or damaged in a way you can't easily detect - and you can get some magic smoke.

That said it's much better than it was - I previously lived through a product development where TI were just shoehorning L-Ion support in to gas gauging chips that were all together too concerned with floating LA cells (including one time when they "forgot" to handing timing in the comms code leaving the SMBus as likely to lock up as IIC )

Having recently got an E-bike myself I was a little bit surprised to see that there are a couple of "official" chargers available: https://www.giant-bicycles.com/global/chargers one which seems to just be a dumb 4A DC supply.
It came with the smart one; they still recommend disconnecting it when full (but then they would ).
I'll generally put it on for 4hrs at a time if I'm not going to be around (as it's never really charging from flat)

The thing that worries me most about it is the charging port could be better protected
- there's a dustcap towards the bottowm of the down tube that pulls down and out, rotating to exposed the socket
even with mudguards on this seems to be in the target zone for everything the front wheel goes over
I keep a brush and cloth next to where I charge the bike in the shed to try and keep stuff out

-sd