i asked about the Cells and BMS etc, - more info. - lets see what i will get back in response - i dont think i will get all the info. but i asked - if a BMS goes haywire for some reason - it should trip the breaker and stop it in its tracks ? safely -
No. Thats the problem. Something goes wrong with the BMS mosfets as its balancing for eg, or at any time, and it shorts out a balance wire which melts insulation, across a couple more, and they all start shorting together and we have a fire. Its not common, but its just one reason that there are so many reports of fires with ev bikes and e cars etc. Or while charging it fails and allows it to over volt a cell, or a pack for hours and heats everything up until the electrolyte boils and its flammable. So any bms error can ignite the thing like a frying pan fire while unattended. Thats why that ev expert that builds EV cars for his customers wont let any vehicle with a BMS into his workshop. But as you say thats exactly what the manufacturers will do.
Thats why we get exploding laptops... And drills. And why all those kids hoverboard balance things were catching fire. The other thing that they will do is have inadequate capacity. So between the BMS charge issues, and the too low capacity on most products, the batteries get a hard time and are discharged heavily in C rate and depth of discharge so will give problems sooner rather than later. And then get an undesereved bad reputation. And none of the true benefits such as longevity and huge range that they promise will be realised. 100Ah is just about enough though even though its now possible to get 180Ah in that space. Just the bms to ruin the job!
You basically swap reliability and fire risk, and shorter a service life, and less range for the dubious convinience of a simple dumb charger. Which you have no means of monitoring or understanding if its working as it should. Seen too many BMS problems! Even my mower is always needing a new BMS... And battery.
Advantage of the PL8 is, as you know, information about whats actually happening. Rapid 1A balancing in smooth proportional way accurate to 3mV, starting at the point you tell it, and total user settings and custom control to ensure healthy cells stay healthy! And it allows you to see problems as they occur. For eg you know your cell 3 is low on capacity. And to be able charge at 40A if in a hurry, or charge from another chair, or a car. And charge anything else you may have! You need to plug both in. But the PL8 needs two presses...
But everyone KNOWS a bms is essential!!! Esp the battery EXPERTS that the manufacturers go to.
Heres a typical BMS for 180A so as long as it doesent fail it will work on a chair (by never actually tripping or doing ANYTHING! But this is typical. It bounces cells up to 3.800v before repeatedly disconnecting the charger... Over and over. Look at its specs.
https://www.aliexpress.com/item/8S-200A ... 75898.html