Mercane (single motor) new BMS

So I decided that I didn't like the way things were appearing on charging since I did my strip down - rebalance - tape back up, so I pulled the battery out and stripped it down again. The first thing I did was measure it.

so while no cells are down below 4V and none at 4.2 (which is safe but not ideal); one is close, and two are below 4.1V.,But given it was charged till it "would take no more" over night and in repeated phases with a timer to boot more should be at or nearer to 4.2.

So up on the ($20 folding) bench (in the kitchen, because I still haven't built my workshop!!) I pull the battery and reopen it after the last surgery.

and am able to plug the new BMS (red arrow) directly into the existing balance wiring harness (yeah), but will need to redo the input wires because the new BMS is a 3 wire BMS and the old is a two.

so this new BMS should be better. So it went in with some minor adjustment, where the charging, battery and power -ve each gets its own port.

Plugged in and working.

Seems good ... lets see

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But alas it was too good to be true, on the way to work this morning:
Speed dropped, voltage dropped and then everything went dark.
So either:

• my soldering failed
• the BMS failed
• something else

Either way, it was an Uber back to my accommodation, stuff it in my truck, and drive that to work.

Worth noting for anyone who thinks having only one scooter is a good solution.

More to follow,turns out it was "something else"; see here.