I ordered an Opus charger to test my cells and a $25 Chinese 58.8v 4 amp floor wart style charger.
I intend to carefully look over the charger for any issues and test the output.
At 15s, that's about 3.92v per cell and I bet there is a trim pot for voltage that I can tweak to bring that up a little higher. I need to do some research on cycle life and cell capacity because I want to live in that power wall spot where cycle life is in the thousands instead of hundreds so I still have good range after 6-7 years and 1,400 round trip commutes.
At 4A, I'm not concerned because it's only about 240 watts in to a 12p battery, that's almost a trickle charger for a 1.9 kwh battery.
If everything looks good and the BMS takes care of the battery, my $25 charger costs a lot less than the alternatives.
I know I can get a Cycle Satiator for $300 or so and there is probably some in between but most of it seems just as sleasy and Chinese so I would rather spend $25.
Sorry for the thread detour.
I saw your latest video yesterday.
If you do decide to redo your nickel-tin strip,I think you should explore the possibility of a deepened saddle bag .50 ammo can so that you can do an equal split side to side and maintain the original gasket seal surfaces. I don't know if the batteries stack well in that space but it shouldn't be too hard to figure out how deep you would need to go and decide if it makes sense.
Widening and messing with the gasket surface just seems like a lot more work.