Firstly, I'd had problems with the bike cutting out for a second or so while riding. I wanted to find a solution to that but it's very difficult to work out what might be wrong when I cannot replicate this in the garage. And it's very difficult to work out what the controller lights might be telling you when they're down on the fuel tank and you're supposed to be watching the road at 80km/hr.
Then I left it off the charger for a month or so and a couple of factors caused the battery to drain. Finding cells that are supposed to be 2.5V minimum at 0.7V is not a good sign. Basically, I don't disconnect the DC converter so it's constantly doing a small amount of work keeping the battery topped up. It then took a fair amount of work, not helped by going away for several weeks, to get the cells back to a state where the onboard BMS would consider charging it again.
So this afternoon after work I took it for a couple of laps around the block here, doing a few gradually increasing loops to see how it would go. I didn't hit the low battery alarm, but I'll keep gradually increasing the distance nearby to see if I can hit any problems and to exercise the battery more. It helps the BMS level out the cell differences.
I've probably lost about half the battery capacity or more. It's very difficult to say without proper testing equipment. But I'm up for a new battery, I fear.
Still, if I can find the cells I want I will get a battery with about 32% more kilowatt-hours (~10KWhr), 36*1.5, weighs 64% (54kg) and takes up 55% of the volume. Just got to hope that someone will sell them to me...
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