Veleco mobility scooters

There's a VelecoEU eBay store on -er- eBay selling spare parts:

That's handy. It looks like many parts are from the Chinese e-bike ecosystem, so it shouldn't be difficult to find similar if not identical parts. Unlike Western e-bikes it's a pretty open ecosystem - rather than using software, communication is often with switches and basic DC voltages so you can easily swap out one electrical part for another.

(in China, there's no hard distinction between pedal e-bike and moped, so often the chunkier ebikes are built like mopeds. Once you have an electric moped you can use many of the same parts to make a mobility scooter)

Theo

Given the publicity that dodgy E-bike fires are receiving at the moment, maybe the DIY approach isn’t the best.

Tim

There is a UK version of that ebay site, parts seem not to be a problem.

My suspicion is that a good chunk of dodgy ebike fires are down to mismatched chargers. Many of them use a standard barrel jack, but if you plug a charger for a 48V battery into a 36V battery, it'll overcharge the cells and cause fireworks. The chargers are typically simple constant-voltage constant-current power supplies and the protection is in the BMS in the battery. But if you overvolt the BMS you may fry it enough to not be able to shut down safely, and then you overcharge the cells and they explode.

In the kind of places where there are fires there may be multiple e-bikes (eg the garages for blocks of flats where several people live who do food delivery) and it would be very easy to plug in the wrong charger. Really we need a bit more smarts to prevent that happening. It's not a problem if you own exactly one battery and use the charger that was shipped with it.

While there are some DIY e-bike builders who are obsessive about balancing and reckon (foolishly) they can live without a BMS, I've not seen anything problematic in commercial e-bikes. Not that I've seen them all of course, nor analysed failure modes, but from what I've seen 'dodgy e-bikes' seems to be a meme that doesn't actually a root cause analysis as to why they are dodgy and how they fail.

Theo