E-bike battery fires

[axel_knutt]

presumably you can still buy CE marked batteries

In an era when you can buy anything from anywhere on Amazon, I wonder just how much use safety standards are anymore. If a backstreet manufacturer in the far east chooses to print a safety logo on a non-compliant or untested product, who's policing it? I wonder how long it would take Trading Standards to test every product on the internet.

It seems to be issues with third party batteries

It was costing me thick end of £100 for kosher Samsung batteries for my old laptop. Or £16 off Amazon.

Best way to nutrilise them is to chuck them in a bucket of water for safety.

Lithium is one of the alkali metals, which burn spontanously on contact with water.

[Cugel]

It's the difference between cheap dumb and expensive smart batteries. If you have a genuine branded product (established brand) from a reputable retailer and look after it according to the manual (and only use genuine replacement parts) chances of you having a battery fire are small. However, if you use non-branded non-genuine replacement batteries you are taking a chance. Maybe they are good, maybe not.

Overall, it's not so much about standards as about the widespread on-line market and a bunch of people who don't understand/care about battery risk and want very cheap prices. Standards are basically irrelevant when there are so many knock-offs available on-line, what we lack is Trading Standards checks and/or other controls.

TPO

P.S. Lipo batteries don't like being drained below 20% or so and fast chargers will hurt them quicker, charge rate is important and even if a battery will "take" a faster rate, a slower charge rate prolongs battery life. And they like to be stored around 50% charge. Doesn't really work too well with a user who wants their battery always ready at 100%, drains it to get most miles out of it then fast-charges it. Old-fashioned pedal bikes have a lot to recommend them!

In some domains, manufacturers still care about the quality of their goods and their good reputation. Elsewhere .....

We have three Fazua-equipped e-bikes, for which the batteries and chargers seem high quality. The oldest is 4 years old and has been charged from 4 to 1 time each week, in the hours just before a ride; and typically from 20 - 40% charge remaining (according to the ten-light display).

We have thought of part charging when the remaining charge following a ride is 20% but advice seems to say that 20% is a safe storage charge - for a week or less, at least; and that less charging cycles overall will prolong the life of such a battery.

According to Fazua, the battery management system never charges up to 100%, controls things like the max temperature during charging and won't trickle-charge if left plugged in once charged. (The charger switches off and goes cool). We never leave the charger unattended in use, though. Similarly, the BMS never lets the battery fully discharge in the bike as its ridden, making the motor unavailable if the battery gets anywhere near empty.

As you say, the better batteries, chargers and BMS do a lot of the safety care for the user. The batteries may cost more (it's £480 for a new 250wh Fazua battery) but their quality means they're less likely to become a safety hazard and likely to last a lot longer than cheaper but poorly-managed batteries. Cost per hour of use is likely to be much better for the expensive batteries than for the cheapies.

Cugel

[Dingdong]

Unfortunately, cheap Chinese batteries, made from recycled cells from only laptop batteries are becoming the norm. They do work, but I worry about their safety aspects.

[mattheus]

Best way to nutrilise them is to chuck them in a bucket of water for safety.

Lithium is one of the alkali metals, which burn spontanously on contact with water.

I think hemo is correct - not based on any chemical knowledge, but from a conversation I overheard here in Battery Manufacture Land [n.b. we make a different flavour of battery]. The water is useful because it conducts adequately for the batteries to discharge through it harmlessly (warming it up, but not boiling if it's a big tank), without needing to attach any complicated/bespoke wiring.

Perhaps Lithium only burns in water in the pure form? So Li salts, or electrolytes of the kind in batteries are safe? This is pure speculation!

[the snail]

Perhaps Lithium only burns in water in the pure form? So Li salts, or electrolytes of the kind in batteries are safe? This is pure speculation!

I think the cells contain Li foil, the cells are safe as long as the cell remains sealed. If they split then they can catch fire, that's the problem.

[hemo]

All my old cells (can type) I disasemble and use the cells for torch's or other small battery projects, end of life cells or lipo I simply lob into a bucket of saline water to kill them off. Saline or water will render them dead after a few days and voltage will be 0v.

[Tangled Metal]

Just up on the departures board at my little station a note that due to safety reasons escooters and ebikes will not be allowed on northern trains from 1st December.

There's a guy with a tiny wheeled ebike and occasionally an escooterist on the train I get in the morning. I wonder what solution they'll come up with?

[hemo]

Simple take the battery off and put in a back pack, no different to a cell phone, notebook or laptop. All have a lithium type battery.

[Bonzo Banana]

I think its important to factor in human error into some maybe most of these fires. I've read of one person riding his ebike into a river by mistake and pulling it out and continuing to use it and the battery ignited I think a day or so later. There have been people have jerry-rigged the wrong charger to work with their battery because they lost or broke the original charger and the charger has been the wrong voltage. Home made battery packs can be poorly made of course and unsafe which has already been discussed but also there is the issue of personal imports where you buy a battery pack or whole ebike from aliexpress or maybe a Chinese seller on ebay. These products may not be certified and tested to be sold in Europe but you bypass that by making it a personal import. I know from experience that products sold within China which look identical to commercially imported products from the same factory can contain different components. The certification may have a set of critical components that must be used in the manufacture for the certification to be valid but sold within China that same product may contain different cheaper components. Even very basic products can be different. Poundland used to sell a very basic bicycle front headlight for £1 and it had zinc plated or stainless steel contacts for the battery contacts but bought from China directly it was basic steel strips and so would corrode very easily even on the water from China so you were always cleaning the contacts. It looked to be the same product from the same factory but just a minor component change meant one was a good quality product and one was poor quality. On an ebike there are probably 100s maybe 1000s of components that can be changed. What is actually a battery pack containing Samsung cells on the commercially imported product may simply be stated to be Samsung on the product from Aliexpress but in fact is cheaper cells that mimic the performance of Samsung cells fairly well but don't quite have the same level of safety or number of charge cycles typically.

I'm in no way pushing to buy the much higher cost commercially imported product as I'm a cheapskate myself but as a past job was a compliance officer I know these issues. Some of the component changes maybe necessary due to radio interference legislation or chemical properties but others are purely quality and safety. I seem to remember from some factories you had to pay extra for copper based electrical cabling over aluminium cabling for the products we were importing and extra for thicker insulation if you wanted it. There were larger heatsinks available if you wanted to improve long term reliability and reduce stress on the components. Also you had to pay for Quality checks if you wanted their frequency increased but I don't think the company I worked for was convinced they would do such checks if you paid for them so they never bothered as far as I remember.

However that is not to say all Chinese companies are always trying to decrease their production costs, they all vary and some Chinese companies nowadays are quality obsessed and produce very high quality products but I personally would say that is a minority of companies over there. In the past I've seen some images of manufacturing conditions in China and its like an old barn with very rough people working in appalling dirty conditions using very basic equipment. They were making basic products like hand tools. I'm sure some batteries are also made in very basic factories with a high turnover of staff, aliexpress sellers for sure.