Death by ebike battery.

Pretty nasty story.

 

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

 

https://www.dailypost.co.uk/news/north-wales-news/woman-died-after-electric-bike-17935702

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.

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.

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.

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. :eek:

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.

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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.

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.

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.

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.

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.

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Edited March 17, 20206 yr by flecc

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?

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).

 

Edited March 17, 20206 yr by Woosh

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.

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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.

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

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.

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.

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.

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

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

To my mind, please correct me if you can bring the relevant facts here, the problems lie with both the sellers of e-bikes and the battery manufacturers, seemingly leaving Joe Public in the dark about maintenance and safety.

Probably because many would be put off if they knew the truth, and would not buy a bike.

In Germany last year, a car delivery transporter trailer with 7 new cars onboard, caught fire due I believe to brakes overheating. There were 5 normal diesel/ petrol cars, which were quickly brought under control by a local, to the Autobahn, fire brigade.

The other two cars were electric and could not be put out. After about 10 hours of fighting the flames, they had to organise a huge tank, fill it with water, and dunk each car for an hour, to stop the chemical combustion - TWICE, once for each car.

Teslas have caught fire, and the time to get out of the vehicle is VERY short!

A Tesla driver was burnt to death last year.

I looked for the video and found dozens of electric car fires. These batteries can be very unsafe under certain conditions, and everyone needs to be fully informed and not kept in the dark:-

https://www.youtube.com/results?search_query=car+transporter+electric+car+fire+germany

regards

Andy

To my mind, please correct me if you can bring the relevant facts here, the problems lie with both the sellers of e-bikes and the battery manufacturers, seemingly leaving Joe Public in the dark about maintenance and safety.

Probably because many would be put off if they knew the truth, and would not buy a bike.

since last year, I affix this label to our bikes/batteries:

 

 

I also post frequently about fire risks, charging, storage of e-bike batteries and recommend members to pay a little more for Samsung and Panasonic 18650 cells.

they explode better if there fully charged and set on fire

The other two cars were electric and could not be put out. After about 10 hours of fighting the flames, they had to organise a huge tank, fill it with water, and dunk each car for an hour, to stop the chemical combustion - TWICE, once for each car.

Teslas have caught fire, and the time to get out of the vehicle is VERY short!

A Tesla driver was burnt to death last year.

I looked for the video and found dozens of electric car fires. These batteries can be very unsafe under certain conditions, and everyone needs to be fully informed and not kept in the dark:-

https://www.youtube.com/results?search_query=car+transporter+electric+car+fire+germany

regards

Andy

 

Agreed, but you'll find that all these fires started by the e-car lithium batteries are Teslas which have caught fire several more times than the twice you mentioned. To give themselves a power density and range advantage they use very large numbers of close packed high density cells of the types we use in our e-bike batteries which are very unsuitable for safe e-car use. One model has 6,200 cells!

 

The launch of their latest model 3 using 21700 type cells* was repeatedly delayed by three years due to lithium battery fires destroying them before the model was finally released to the public.

 

Other makes haven't had these problems. The largest selling one and earliest affordable e-car is the Nissan Leaf which with some third of a million on the road sold during the last ten years has never had a lithium traction battery fire.

 

I carefully specified that exactly since one Leaf had a conventional car fire in it's normal lead-acid battery circuit which some have wrongly said was the traction battery, which was not in any way involved.

 

For further clarity the Leaf's underslung lithium traction battery with its much smaller number of very different low density cells is exclusively used just for traction. For all the normal car electrical functions they use a normal car battery under the bonnet in conventional car battery circuitry. This as we know can cause under bonnet car fires in certain circumstances, but at least on an e-car there's no tank of fuel to add to the fire or ignite in a collision.

 

N.B.

 

* 21700 cells announced by Samsung and LG Chem in 2015 for use in electric bikes. By January 2017, was being produced at Tesla Gigafactory 1 for the Tesla Model 3, reaching an annual production rate of 1.8 billion cells annually (20 GWh per year) by mid-2018, with a July 2019 Tesla forecast that they would ship 2 GWh of batteries in 2019.

 

Alarmingly these batteries when at end of Tesla car life are used in home powerwalls, and they are also installed new in powerwalls.

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Edited March 17, 20206 yr by flecc