It’s been 4 months on this setup so far.
Monday night I tore the battery apart and balanced it. The cells were out only .03v total. My tools only go down to .01v, so I can see .005v by measuring two cells ie 3.54+3.54=7.09 which means both those cells are actually 3.545v. Got it down to where all the cells showed the same so probably .01v total with errors. Using a little RC charger plugged into the battery’s balance plugs.
The “up” button on my primary high power charger broke; I can still adjust a setting up by sticking a piece of metal where the button used to be. To charge 110v it turns the amps down to 35a but that’s too much for a 110v plug anyway, so if I turn it down more I risk not being able to turn it back up for 50 amp level 2 charging. So I had to come up with a 110v home charging setup.
Enter boost charging. The controller has a special feature that allows me to boost voltage from any PSU by using the motor coils as a DC-DC step-up converter. Any power supply from 24v up to the minimum batt voltage will work.
So I built this 60v 20a 2s charger to boost charge, using 2x 24v 20a 500w power supplies. I’ve seen them do 700w in the past. Currently only doing 15a but I need to fix one of the PSUs to allow current up to 30 amps. In this case the PSU is giving 60v 16a which is stepped up to 77-90v 10 amps automatically by the controller.
The boost charger power supply negative connects to controller/battery ground, and the positive connects to one of the motor phase wires. The controller auto-detects the PSU and begins the charge.
