Party Vibe

@cheeseweasel 702416 wrote:

After speaking to a couple of local e-bike shops, I’m still oned to think the BMS needs replacing. The BMS is a piece of circuitry that balances the 16 groups of cells to ensure that they charge and discharge at the same rate, as well as doing other clever stuff to protect the cells (I learnt this yesterday). The measured voltage across each group of cells is roughly the same, suggesting that none of the cells have failed. I don’t want to get into replacing cells if possible as they are all hot-glued into the enclosure and will be a PITA to remove, and also I don’t have the welding tool needed to connect them together with aluminium ribbon. I’ve also been warned that they’re prone to explode violently if you mess around with them, e.g. heating them up too much with a soldering iron. So I think I’m just going to order the new BMS (hopefully ~£20) and hope for the best.

Currently trying to source another one from China.

apologies for delay in replying but you had diagnosed the problem correctly; there is always a risk of Fire with these sorts of accus (any parcel which might contain one has all sorts of warning labels) and other than replacing the accu (which isn’t cheap and gives up the ghost anyway after 3-5 years same as with laptops and other devices which run their batteries hard) that is by far the best idea.

a few words of caution – a 48V e-bike is unusual in Europe as it normally has enough power to exceed the legal speed limit of 25 km/h unassisted.

After that it becomes a “speed pedelec” which often requires a similar license (and helmet, reg plates etc) to riding a small moped. if someone rides such a machine in a manner that attracts the attention of traffic cops; they are likely to get hauled up and points on their driving license (whether it is full or provisional) for “otherwise than in accordance with a license”.

they would normally have to be riding particularly badly or agressively (like 30 km/h + in a pedestrian area) to get caught like that (its always been possible to get a fine for riding a pushbike dangerously) but it can happen. There is CCTV which can be matched up with reports of “anti social behaviour”.

Traffic cops start to look at you oddly when you are going 18 km/h uphill (there are hills in East Anglia, though not as steep as in the West) with a full set of panniers anyway (even though that is legal).

@cheeseweasel 702421 wrote:

Yeah, bombing up the hill at 20mph overtaking other cyclists puffing and panting their way up was pretty fun, until the thing conked out and I was left having to pedal something that weighs twice as much as a normal bike. [/quote]

On mine the connections to the motor can shake loose (if not inspected every so often); this happened to me shortly after riding into the grounds of a local Catholic school slightly too fast than I should have (thought they were 10 mph speed bumps, but they were 5 mph and the signs only appeared after the speed bumps) as I was returning one of the sixth formers ID cards she had dropped in the street. In spite of being noticed by half the kids (before the teacher, who was looking up prayers on his smartphone for chapel) I didn’t trigger the “stranger danger” alert; they probably thought I was a new teacher….

Quote:

I’m tempted to get one for myself, but they do seem quite expensive for what they do (compared with, say a 2nd hand motorbike), and I’d be worried about it getting nicked if I left it in public.

A decent well built push bike (either an MTB or the kind you would try and win races with if fit enough) costs as much or more than a modern e-bike and is equally at risk from theft if parked anywhere sketchy; unless you use a lock that adds as much weight to the bike as the accu. Most homes, shops and businesses in UK frequented by cyclists find some space for bikes to be brought inside and stored, in other European countries (and even Swindon) they have indoor bike parks with security.

Riding one is less dangerous than a motorcycle (I considered getting one myself; but decided against it after a friend who had disappeared for a few weeks and reappeared on crutches for some weeks – at least he wasn’t too badly injured) the running costs (even after considering replacing accus etc) way less than a car. The electricity required to charge one is less than would be used by a desktop computer and sound system for processing real time audio or playing modern computer games / watching videos/TV for the same amount of hours.

With a “European” rear rack and panniers you can easily haul around 25 kilos as well as yourself (which is not as easy to do on a push bike even if you are relatively fit).