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Aftermarket battery burst into flames and burned for half hour - plus, our tips on how to avoid e-bike battery pitfalls

A cyclist in southwest London had a lucky escape when the battery powering a motor he’d had fixed to his mountain bike exploded and burst into flames.

A man who witnessed the incident from a nearby pub told the Sun that the battery continued to burn for half an hour, with several explosions sending debris into the air.

Video and pictures on the newspaper’s website suggest it was a Scott mountain bike fitted with an aftermarket rear-hub motor.

Hedge fund manager Peter Taylor, 57, was drinking with friends at the Royal Standard pub in Wandsworth on Friday evening when the dramatic episode unfolded.

He told the Sun: “There was smoke and flames coming from this pushbike under the rider. He hopped off, dumped the machine and sprinted to safety.

“We couldn’t believe how big the fire was.

"Flames were shooting into the air and there was popping and banging, like a fireworks display.

“Some of the exploded battery parts hit parked cars. Someone from The Alma pub down the road got a fire extinguisher but the blaze refused to go out. Eventually the fire brigade turned up.

"They even put ladders on rooftops to check for battery remnants.”

He added: “The rider — he was in his 30s — wasn’t hurt.”

> Bike lights explode, almost burn down cyclist's house

If you’re looking for an e-bike that won’t burst into flames, head over to our sister site ebiketips.co.uk where you’ll find everything you need to know about them.

Dave from ebiketips, said: “There are a lot of aftermarket e-bike kits readily available in the UK, some of which are legal for use on UK roads and some which are not: if it's over 250W, has a throttle instead of being pedal-assist, or doesn't have a speed sensor to cut the motor above 25km/h, it's not legal.

“Obviously when you're buying direct and cheap you're putting yourself at the mercy of a manufacturer's quality control, and it's often difficult to know what the build quality of a system is even after it arrives.

“Lithium-Ion e-bike batteries are generally made up of an array of smaller cells, usually 18650 cells of which you need around 40 for a standard e-bike battery.

e-bike battery cells.jpg

e-bike battery cells.jpg

“They're well-known for being flammable if they short-circuit or if there's a weak point in the system where heat can build up, and it's not only budget manufacturers that have issues: look at Samsung's problems the the Galaxy Note last year.

“But the lower the price, the more you can expect corners to have been cut.

“Our advice would be to choose carefully, and not just to go for the cheapest system you can find.

“If you do want an inexpensive e-bike then there are manufacturers of both full bikes (B'Twin, Cyclotricity, Powacycle) and retrofit kits (Panda, Dillinger, Woosh) that will back up their bikes or systems with a full UK warranty.”

Born in Scotland, Simon moved to London aged seven and now lives in the Oxfordshire Cotswolds with his miniature schnauzer, Elodie. He fell in love with cycling one Saturday morning in 1994 while living in Italy when Milan-San Remo went past his front door. A daily cycle commuter in London back before riding to work started to boom, he's been news editor at road.cc since 2009. Handily for work, he speaks French and Italian. He doesn't get to ride his Colnago as often as he'd like, and freely admits he's much more adept at cooking than fettling with bikes.

15 comments

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Yorkshire wallet [1710 posts] 8 months ago
2 likes

There was some bellend on Hotdeals the other day going on about his moped-like-speed on one of these 'aftermarket' motors. Hopefully his balls will get burned off.

Just get  moped and don't ride in cycle lanes at that speed.

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brooksby [2927 posts] 8 months ago
0 likes

Seems like, if you want an ebike then buy an ebike; don't just buy a motor and fit it to your normal bike.

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FatBoyW [248 posts] 8 months ago
0 likes

Yeah - its scary how so much aftermarket battery gear seems to be a lot dodgy puts me off buying lights of the internet.

Round our way these guys seem good:

http://www.velo-fix.co.uk/warwickshire-e-bikes

 

They are nothing to do with me but I might being getting an ebike for a friend!

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Peowpeowpeowlasers [572 posts] 8 months ago
10 likes

"I'm going to buy a large battery that can store a huge electrical charge, and I'm going to buy it from the cheapest source I can!"

Yep, great idea.

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StuInNorway [150 posts] 8 months ago
0 likes

I'm struck by 2 things here - WHY would you fit an e-bike motor to a MTB with full suspension ? (Why would you even have one in London and use it on the road, they're crap on road rides)
As the story is in the Sun, there are almost as many pictures as words, in fact some of the pictures feature several times.
The number of these Fleabay special motor kits i see going cheap online, something has to give. I often see the same battery packs offered with the "normal" 230w setups, and with the 500w (Illegal in Euro-land) versions, that pull twice the current and will almost certainly overoad the battery - but then once it's incinerated, you can't really send it back to China for a refund.

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Grahamd [872 posts] 8 months ago
7 likes

This is excellent news and should be widely circulated. Once car drivers become aware that the cyclist they are passing might be riding a bike ready to explode they will be guaranteed to give a wide berth for fear their tin box might be damaged.

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Yorkshire wallet [1710 posts] 8 months ago
0 likes
Grahamd wrote:

This is excellent news and should be widely circulated. Once car drivers become aware that the cyclist they are passing might be riding a bike ready to explode they will be guaranteed to give a wide berth for fear their tin box might be damaged.

Don't be giving ISIS any ideas.

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rkemb [57 posts] 8 months ago
4 likes
Peowpeowpeowlasers wrote:

"I'm going to buy a large battery that can store a huge electrical charge, and I'm going to buy it from the cheapest source I can!"

Yep, great idea.

This reminds me of the story that one of the Apollo astronauts had the thought, as the rocket motors started up, that every component had been supplied by the lowest bidder.

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WillRod [254 posts] 8 months ago
1 like

Lithium Polymer (LiPo) batteries are quite dodgy things if not treated properly.

They don't like getting too hot, being worked too hard, being hit or puncture and that's before you get into charging and discharging. Most of these cause fires that are self-sustaining.

If matched correctly to the electronic speed control and motor, as well as the charger, you will be fine. It seems to me that this is probably a cheap Chinese e-bike kit installed on a £200 pogo-stick full suss bike.

If you are interested in one that won't self combust, you can build a LiFePO4 battery pack, as these are more stable and will last for more charges. If you don't fancy that, then stick to official kits and accessories.

 

 

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Mungecrundle [866 posts] 8 months ago
3 likes

Who could have anticipated that a DIY bodge job involving a powerful battery cell of dubious provenance might end up causing a fire?

These things must be banned before someone who knows what they are doing creates a practical and safe transport alternative to the internal combustion engine.

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ConcordeCX [640 posts] 8 months ago
1 like
Mungecrundle wrote:

Who could have anticipated that a DIY bodge job involving a powerful battery cell of dubious provenance might end up causing a fire? These things must be banned before someone who knows what they are doing creates a practical and safe transport alternative to the internal combustion engine.

the external combustion engine?

the spontaneous combustion engine?

 

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timclarkih [13 posts] 8 months ago
0 likes

sorry, I can't delete this post

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timclarkih [13 posts] 8 months ago
2 likes

This was the bike . The other side of the frame had a big melt hole in it.

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Bob F [44 posts] 8 months ago
1 like

And still some companies ship these things - undeclared - by air........

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niico [9 posts] 8 months ago
1 like

Somethinkg I've learnt the hard way - never buy cheap batteries or chargers.

Only buy batteries & chargers from large brands you trust - not from dodgy backstreet chinese places on eBay who don't care if the battery explodes in your pocket (happened to me) or breaks your iPhone (also happened to me).