Changes to selling e-bikes, conversion kits and batteries on eBay.co.uk - No more private (personal) sales.

[Ghost1951]

In my own tribute to Flecc's "EAPCs/Pedelecs vs the rest" crusade (to get that distinction widely used and into the media), I want to propose that we call rubbish batteries Cell-packs. Any safe BMS protects against over-voltage, over-current in and out and over-temperature, plus other functions that can indirectly add to safety but are mainly about protecting the cells. When these limits are breached it cuts off.

So over-charging can only happen to an Under-Protected Cell-Pack, one with a BMS that's missing core safety functions or with no BMS at all. It's like having a leaky case; the cells need basic electrical and physical protection.

The distinction is vital to recognising that over-charging isn't a consumer misuse issue, it's a cost-cutting issue, whether responsibility lies with the buyer of a shrink-wrapped lump or with the supplier of a branded battery who tries to pass off a proprietary socket as adequate compensation for a cheap sub-standard BMS. There's no harm in having additional layers of protection: a matched charger and/or a timer, but only the BMS is an integral part of the battery.

Careless people aren't necessarily stupid either, they're just ignorant until 1) they've been warned what not to do and 2) they've been warned about the consequences, which the trade is naturally reluctant to do. Even then we all get an off day. Compare with petrol or domestic mains. Consumer misuse and reasonable consumer abuse - curiosity / kids / mild tampering - shouldn't be costing lives to this extent.

I'm not going to argue against what you are saying there in general, but this ebike demonisation pattern we now see is a storm in a tea-cup when you look at the power technologies we have taken for granted in the twentieth century and up to now, and have tolerated on open sale to every numpty in society.

Here's the core of what I am saying - how many people are hurt by petrol and other volatiles that are readily and everywhere available? Go to ANY garage with a can and fill it with petrol for lighting your barbecue (no - DON'T) - but you can and nobody turns a hair. How many people are electrocuted or injured by electric shock every year in this country? EVERY one of us here has probably had a nasty belt from the mains. We are the ones that lived to tell the tale. I've had several - the worst of which came from a big fat capacitor sitting at 800 volts in a radio transmitter I was fiddling with. I didn't know what had hit me. Banged my head badly. Touched the anode of an old transmitting valve with a metal screwdriver.

CCTV footage of Alloa explosion shows flames bursting from building #shorts

CCTV footage of Alloa explosion shows flames bursting from building

www.youtube.com

Why are we still piping methane gas into our houses?

 

[soundwave]

everything blows up if u set fire to it

 

[AntonyC]

I am not sure that the BMS is at fault in those situations. It could well be that one of the cells has gone bad, causing the charging process to continue until the bad cell starts to burn [...]

My advice is call and talk to your suppliers before you buy.

No the over-voltage sensing is at cell level (which I should have written) so I think you'd need 2 cells in a P group to fail simultaneously to go undetected. I think temperature sensing should always be at multiple points throughout the pack, as some batteries are, because both internal and external causes can heat one end of the battery.

Sound advice as ever.

 

[Woosh]

No the over-voltage sensing is at cell level (which I should have written) so I think you'd need 2 cells in a P group to fail simultaneously to go undetected. I think temperature sensing should always be at multiple points throughout the pack, as some batteries are, because both internal and external causes can heat one end of the battery.

Sound advice as ever.

when a cell goes bad, for example developing dendrites which act as micro-shorts, it usually causes the cell to heat up and the block to have a lower voltage than otherwise. There is no simple way for the BMS to detect this. Eventually, the shorts spread and start a fire.

 

[Ocsid]

We don't store cans of petrol within the habitated part of our homes, unless we have some cognative issue, nor do we store large quanties of mains gas in our homes, in ways directly comparible with storing the quantity of energy our ebikes or scooter batteries do.
Nor is much else with that potential energy stored up sitting there connected to a potential ingition source.

I don't see these arguable parallels, with anything else we are likely to store in a stair well or other part of our homes that clearly some do.

 

[AntonyC]

when a cell goes bad, for example developing dendrites which act as micro-shorts, it usually causes the cell to heat up and the block to have a lower voltage than otherwise. There is no simple way for the BMS to detect this. Eventually, the shorts spread and start a fire.

You're describing a fault within a cell, while I was saying a BMS is unfit if it can't prevent damage through over-charging, an external factor. The BMS controls the electrical interface to the outside world i.e. the battery ports; it doesn't have that control over physical events like cell breakdown, severe shock or water ingress.

We don't store cans of petrol within the habitated part of our homes, unless we have some cognative issue, nor do we store large quanties of mains gas in our homes, in ways directly comparible with storing the quantity of energy our ebikes or scooter batteries do.
Nor is much else with that potential energy stored up sitting there connected to a potential ingition source.

Agreed indoors multiplies the hazard but we've mains electricity that can easily kill but doesn't that often.

If by potential ignition source you mean a charger, then the problem is with the under-protected battery in my view: the energy store has to include its own protection. Relying on something separate like 'the right' charger is like a notice saying not to use phones at the pumps, what mainly keeps petrol comparatively safe is the design of the storage and transfer. Worse, whenever blame is shifted onto users for an 'over-charging' incident a seriously deficient product isn't getting talked about. The user might have bought a battery instead of an under-protected cell-pack had they heard of the distinction.

 

[saneagle]

when a cell goes bad, for example developing dendrites which act as micro-shorts, it usually causes the cell to heat up and the block to have a lower voltage than otherwise. There is no simple way for the BMS to detect this. Eventually, the shorts spread and start a fire.

If that were true, your customers' bikes would be catching fire. When you started selling ebikes, you didn't care what cells were in them. They used cheap batteries. None caught fire. You had racks of batteries on charge in your shop. None caught fire. I think you need to look at your theory again.

 

[Woosh]

If that were true, your customers' bikes would be catching fire. When you started selling ebikes, you didn't care what cells were in them. They used cheap batteries. None caught fire. You had racks of batteries on charge in your shop. None caught fire. I think you need to look at your theory again.

The cheap ebikes that I sold in the early years had lead acid batteries. The more expensive bikes of 14 years ago had 36V 10AH rack batteries and pouch cells. For the last 10 years, we use only Samsung and Panasonic cylindrical cells. We stopped top up charging ever since going for cylindrical cells. We wrote to all customers of batteries with pouch cells suggesting they upgrate their batteries to Samsung and Panasonic cylindrical cells. That was 7-8 years ago. There may be still one or two with 10-14 years old pouch cells in their shed but I doubt that they are still functional.

 

[kevsbike]

I'm not sure if the changes are a good or bad thing. I took a punt on a private sale Wisper 705 on eBay at the beginning of 2023 when I felt like I needed a bit of assistance after getting Covid in late 2022 but I think the seller was less than honest about the condition of the battery as the screws were missing from it when I belatedly took it out of the bike a year later to check the voltage!

In any case it ceased to be a problem when someone stole it earlier this year, which brings me to my main point.

It will reduce the opportunities for the disposal of complete stolen bikes which has to be a good thing, surely? I think the "battery fire risk" is a convenient scapegoat when you have 1000w-2000w kits being openly sold on eBay but a simple requirement to post the frame number on a listing, whether it's Gumtree or FB Market Place would also go a long way in reducing bike theft.

 

[saneagle]

The cheap ebikes that I sold in the early years had lead acid batteries. The more expensive bikes of 14 years ago had 36V 10AH rack batteries and pouch cells. For the last 10 years, we use only Samsung and Panasonic cylindrical cells. We stopped top up charging ever since going for cylindrical cells. We wrote to all customers of batteries with pouch cells suggesting they upgrate their batteries to Samsung and Panasonic cylindrical cells. That was 7-8 years ago. There may be still one or two with 10-14 years old pouch cells in their shed but I doubt that they are still functional.

How many caught fire?

 

[Woosh]

How many caught fire?

One of the pouch cells, none of the Panasonic and Samsung cells.

 

[saneagle]

One of the pouch cells, none of the Panasonic and Samsung cells.

You sold an ebike that caught fire?

 

[Woosh]

You sold an ebike that caught fire?

Yes, it was 9 years old when smoke came out of the battery.

 

[flecc]

Why are we still piping methane gas into our houses?

That's nothing.

When I first moved to my present home we still had so called Town Gas, gas baked from coal, converting it to coke,

That gas was just as capable of blowing the front wall from our buildings, it was also lethal to breathe and a very popular method of committing suicide:

"Coal Gas in the United Kingdom

Prior to the 1950s, domestic gas in the United Kingdom was derived from coal and contained about 10-20% carbon monoxide (CO). Poisoning by gas inhalation was the leading means of suicide in the UK."

Means Reduction Saves Lives

A number of studies have indicated that when lethal means are made less available or less deadly, suicide rates by that method decline, and frequently suicide rates overall decline. This has been d…

www.hsph.harvard.edu

.

 

[kevsbike]

Why are we still piping methane gas into our houses?

That's nothing.

When I first moved to my present home we still had so called Town Gas, gas baked from coal, converting it to coke,

That gas was just as capable of blowing the front wall from our buildings, it was also lethal to breathe and a very popular method of committing suicide:

"Coal Gas in the United Kingdom

Prior to the 1950s, domestic gas in the United Kingdom was derived from coal and contained about 10-20% carbon monoxide (CO). Poisoning by gas inhalation was the leading means of suicide in the UK."

Means Reduction Saves Lives

A number of studies have indicated that when lethal means are made less available or less deadly, suicide rates by that method decline, and frequently suicide rates overall decline. This has been d…

www.hsph.harvard.edu

.

Beat me to it! Ironically, "natural gas", methane was a danger in coal mines, being odourless, and with the risk of suffocation and/or explosion is why an odorant is added to it before it is piped into our homes, as it doesn't have a distinct smell, like coal or "town gas". I can just about remember the old gasholders coming down but Burton-on-Trent is famous for being the first place in the UK it was introduced!

https://www.itv.com/news/central/update/2012-07-18/45-years-of-natural-gas/

 

[flecc]

Beat me to it! Ironically, "natural gas", methane was a danger in coal mines, being odourless, and with the risk of suffocation and/or explosion is why an odorant is added to it before it is piped into our homes, as it doesn't have a distinct smell, like coal or "town gas". I can just about remember the old gasholders coming down but Burton-on-Trent is famous for being the first place in the UK it was introduced!

https://www.itv.com/news/central/update/2012-07-18/45-years-of-natural-gas/

And here in the London Borough of Croydon we were one of the last to convert.

But I didn't wait for it to happen. A year earlier in 1970 I put myself 55 years ahead of the government by converting entirely to electric and had the gas meter ripped out.
.

 

[Woosh]

And here in the London Borough of Croydon we were one of the last to convert.

But I didn't wait for it to happen. A year earlier in 1970 I put myself 55 years ahead of the government by converting entirely to electric and had the gas meter ripped out.
.

Don't you miss cooking with gas?

 

[flecc]

Don't you miss cooking with gas?

No. Cooking with an electric hob is just a different set of skills that I've been using for 56 years now, at first with radiant ring but soon changing to ceramic hob for the ease of cleaning.

If it really is found difficult, there's always the option of an induction hob with suitable pans which closely mimics gas advantages, but I've never felt the need.
.

 

[guerney]

No. Cooking with an electric hob is just a different set of skills that I've been using for 56 years now, at first with radiant ring but soon changing to ceramic hob for the ease of cleaning.

If it really is found difficult, there's always the option of an induction hob with suitable pans which closely mimics gas advantages, but I've never felt the need.
.

I may be heading in the opposite direction because in my experience, the elements of ceramic hobs don't as last long, are difficult and much more expensive (pricier than the hobs) to source, and my new one isn't even designed with repair in mind - although it's currently working ok (apart from a few months ago when one hob switched to full power by itself, and wouldn't switch off... suddenly incinerating slow cooked lamb to ash, I suspect because of a fault which originated from 3 hour-long use of a thick heavy cast iron pot at low level, the radiant heat from which terminally [possibly] confused the control board [I reckon it crashed, possibly due to overheating] via heat sensors being activated under other rings, despite those rings being off) case is RIVETED! With metal tough enough to completely resist genuine cobalt drill bits. Leaving it without power for 24 hours reset the control board, works ok again now, about six months and counting. Also, the glass surface of ceramic hobs crack easy. If water gets through those cracks, mixes with oil bult up over time with cooking to form droplets, they can explode - that's what happened with my previous ceramic hob. Fortunately, my face wasn't above the glass at the time, and it didn't send toughened glass shards through my head and body because most of the force expelled from holes in the case underneath with a loud WHUMP! And a bit of a jump. But most built-ins are usually easy to install yourself. Install them wrong by sticking the top glass down with silicone sealant or strong adhesive, which won't allow the glass top to expand, and you'll have the glass cracking problem leading to the explosion scenario - the glass sheet should glide over heat resistant foam tape, as it expands and shrinks with heat. Avoid scratching the "toughened" glass with heavy cookware or over-enthusiastic cleaning, because that can lead to cracks, which leads again to the explosion scenario. So much easier and cheaper to swap out normal electric cooker elements.

 

[saneagle]

Gas is cheaper, easier to control and virtually zero maintenance cost. It also still works when there's a power cut. I've never experienced a gas cut in my lifetime.