Death by ebike battery.

[Andy McNish]

Pretty nasty story.

Daily Post: Woman died after electric bike battery exploded while charging in her motorhome.

Woman died after electric bike battery exploded while charging in her motorhome

Christabel Timmins died in hospital weeks after the incident in Dwygyfylchi

www.dailypost.co.uk

 

[Nealh]

Yes it is nasty and certainly charging in very small enclosed space is not good, I for one would never charge in a caravan type vehicle.
It only takes one cell to go thermal and cause an incident, the battery if the same one had previous history and shouldn't have been repaired.
Which is why a lot of batteries are recycled instead of being repaired.

Incidents are fairly rare though.

 

[Deleted member 25121]

It would be rather irresponsible to re-cell a battery pack and not fully test it afterwards, the very thought of that makes me shiver.

 

[Nealh]

The re - celling of a pack is often not the issue, the replacement of a few cells may well be esp if none of the others are fully tested, which is why in most cases we advise posters not to replace cells. There was one recent post where someone had cells that were really bad and I think read 0v or certainly below 2v, at that stage they need chucking and battery is better recycled or the cells used as single use cells.

 

[Deleted member 25121]

A big risk in re-celling a pack is in introducing a short circuit somewhere in the battery pack, maybe a sliver of metal that bridges across a cell or cells when the pack is hot.

I remember hearing a long long time ago that the energy density inside a mobile phone battery was greater than that in a hand grenade and ebike battery packs are an awful lot larger.

 

[flecc]

Fortunately for the industry this appeared in a local news source. In a national newspaper it could have had a serious effect on sales. Nonetheless, appearing shortly after an e-bike killed a woman in an accident it is damaging.

These coming at a time when covid-19 is seriously damaging the economy is especially unfortunate.
.

 

[Nealh]

A decent construction will use added protection on the v+ end, I always use another card ring to prevent the short risk and cell spacers.

 

[Deleted member 25121]

It doesn't need much to bridge across, a strand of wire loose in the box can do all sorts of damage.

Anyway, it would be awful to re-cell a pack and not even test that it can be charged and discharged. That alone should put people off getting them re-celled.

 

[mike killay]

Worrying,
When you think of all the lithium cells I recharge in the house.
Shaver, toothbrush, vapes, phone, tablet.
With the ubiquity of usb recharging, more and more things are re-chargeable.

 

[Deleted member 25121]

Worrying,
When you think of all the lithium cells I recharge in the house.
Shaver, toothbrush, vapes, phone, tablet.
With the ubiquity of usb recharging, more and more things are re-chargeable.

The lithium batteries in those things are safe enough nowadays, problems start when people dismantle packs of cells and replace the cells without taking meticulous care, as I'm sure Nealh does.

Here's something to think about though - I remember flying to China over 10 years ago and taking some of those little battery powered fans in my suitcase. They used AA NiMh batteries which I'd left in the fans, when I got to my hotel and started to unpack I saw that the on/off switch on one of the fans had been knocked on, the plastic fan case had melted and surrounding items in the case were still warm.

That was very scary, it could have caught fire in the hold. Airlines have since introduced regulations about dealing with batteries.

Since them I always remove whatever batteries I can when flying and wrap them up so that they couldn't touch each other. I also take care with all batteries.

 

[flecc]

When you think of all the lithium cells I recharge in the house.
Shaver, toothbrush, vapes, phone, tablet.

The lithium batteries in those things are safe enough nowadays,

I only ever do any lithium battery charging when I'm in and wide awake, because even those small ones are not unconditionally safe. I've had two swelling up with internal shorts, one of them a Canon camera battery that I caught just in time. It was actively swelling and I had to use a small screwdriver to lever it out of the camera.

The other was a Nokia phone battery that had swollen, stable but no longer any use.
.

 

[UrbanPuma]

I've heard there are companies that recondition old batteries, eliminating the need to pay huge prices for a new one. How safe is this process and is it better to always buy a new battery rather than using one of these firms?

 

[Woosh]

I've heard there are companies that recondition old batteries, eliminating the need to pay huge prices for a new one. How safe is this process and is it better to always buy a new battery rather than using one of these firms?

Lithium batteries are improving all the time but they should be binned after 7 years, much less if they are left unused for long period, a year or more.
It's really a case of use it or lose it.

When they are left unused, dendrites form on the surface of the electrodes causing short circuit when you put them back on charge.

This is what happens to the electrodes:

If you want to revive a battery after a very long storage, check the voltage first.
If it's less than 33V (for a 36V battery), contact your suppliers for advice.
If it's above 33V then charge it back to full where the fire risk is prevented (like outdoors).

 

[flecc]

Lithium batteries are improving all the time but they should be binned after 7 years, much less if they are left unused for long period, a year or more.
It's really a case of use it or lose it.

Used or not, to keep them in good condition I recharge all my small lithium batteries and a couple of lead acid batteries every two months and have a card recording every charge date. Coincidentally I did that this morning 17/3/20, the previous charge being on 12/1/20.

I started this routine on 14/2/1999 with a minidisc lithium battery which was still working well with two thirds capacity when I scrapped the unit in 2016 at 17 years old.

So looking after them does pay off.
.

 

[UrbanPuma]

Lithium batteries are improving all the time but they should be binned after 7 years, much less if they are left unused for long period, a year or more.
It's really a case of use it or lose it.

When they are left unused, dendrites form on the surface of the electrodes causing short circuit when you put them back on charge.

This is what happens to the electrodes:

If you want to revive a battery after a very long storage, check the voltage first.
If it's less than 33V (for a 36V battery), contact your suppliers for advice.
If it's above 33V then charge it back to full where the fire risk is prevented (like outdoors).

I've had mine for 8-years now and think I'm down to about 10-12-miles per charge. I was thinking of reconditioning it, but after receiving this information, I'll definitely opt for a new battery when ready. Thank you for your comprehensive response.

 

[Michael Price]

I have not heard of this before with an ebike battery but I have seen the aftermath when an much smaller ecig battery blew up - and having worked with computers for many years I have heard of a lot of laptop batteries catching fire
The normal reason for these things happening seems to be using the wrong charger.
In this case it seems like the company that did the recell were to say the least negligent!
I had a battery from my old ebike recelled and the company claimed to have fully tested it before returning it - and I have never heard any complaints about them.

feel sorry for them though - must have been terrible

 

[Nealh]

The re - celling done professionally should pose very few issues, Jimmy is an expert at this.

I build my own but would never do so for anyone else mainly for legal reasons.

 

[Woosh]

In this case it seems like the company that did the recell were to say the least negligent!

replacing the cell pack with a new factory made cell pack is easy and relatively safe because the only difference with a new battery is the casing and the sockets but that is not what he did.

What he did was repairing two faulty batteries. Their cells are well old. If the cells developped dendrites, then the fate of the repaired batteries was sealed.

Since 2 years ago, manufacturers made their batteries unrepairable and unrecellable to stop this sort of accidents. The inside of the battery is all gunked up with silicon rubber.

 

[Deleted member 25121]

The re - celling done professionally should pose very few issues, Jimmy is an expert at this.

I build my own but would never do so for anyone else mainly for legal reasons.

Even professionals can make mistakes and unfortunately in the case of re-celling a battery pack they can be fatal to life.

Do you know if Jimmy tests out the re-celled battery packs under load for prolonged periods of time and also being charged from low to full using the charger that came with the pack?

Also, does he have full insurance I wonder.

I'm a professional electronics engineer and I wouldn't trust anybody with re-celling one of my packs.

 

[sjpt]

I'll definitely opt for a new battery when ready.

Or as Nealh says, have it recelled by an expert (such as Jimmy)