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Some time ago there was a thread about "open source BMS" this led to what is now a proprietary BMS offered by Clean Power Auto. An issue with nearly all proprietary stuff is that secrecy masks deficiencies I'm not saying there are any deficiencies in the MiniBMS being marketed today. Is there interest here in continuing the open source development, right through a group buy? If so we can restart the activity. I have taken the last posted schematic as a conceptual start and fixed the many problems I found in it. I have also laid out a PCB. I chose a DC rated fuse rated at 300 volts and added a large TVS to guarantee no fires. I added hysteresis to the HVC and tightened tolerances on it and the onset of shunting. I changed the inductive shunt resistor to an array of SMD resistors to avoid long term issues with the shunt transistor. The design I've done is focused on CALB batteries. It assures that HVC of all cell modules is 3.6volts +/- 1%, that shunting begins at 3.46 volts +/-1%, that any cell that reaches HVC must fall about 70 millivolts to reset the HVC status. LVC is temperature sensitive and 2.5 volts +/-2% at zero degrees C and 2.7 volts +/-2% at 50 degrees C and once LVC is set the cell voltage must rise about 100 millivolts to reset it. The cell module is 1.225" x 1.875". The current loop conects to the cell module through " 250 Faston " connectors.
OPEN SOURCE MEANS NO SECRETS.
Regards
Jerry Liebler
OPEN SOURCE MEANS NO SECRETS.
Regards
Jerry Liebler