Midwestdrifter
Engineer In Residence
A few notes as I wind down the testing.
The Orion BMS requires some cell taps to be attached to a specific cell when not in use. Failing to do so can cause the ASIC which reads cell voltages to pick up noise, creating a random fault code, which made me think the BMS was failing.
The Jr 2 also uses the current convention where positive current is discharge, and negative current is charge. I got them backwards, and it caused me an hour of fiddling.
For SOC calibration, I have decided to use only upwards drifts. Specifically at around 3.5Vpc it resets to full. Though I may add a down drift at the lower knee if I find myself spending a lot of time there.
I am only seeing about 30mv drift at 200A discharge, so the cells seem well matched. I will do a full discharge capacity test tomorrow, and log it all for a nice graph.
The Orion BMS requires some cell taps to be attached to a specific cell when not in use. Failing to do so can cause the ASIC which reads cell voltages to pick up noise, creating a random fault code, which made me think the BMS was failing.
The Jr 2 also uses the current convention where positive current is discharge, and negative current is charge. I got them backwards, and it caused me an hour of fiddling.
For SOC calibration, I have decided to use only upwards drifts. Specifically at around 3.5Vpc it resets to full. Though I may add a down drift at the lower knee if I find myself spending a lot of time there.
I am only seeing about 30mv drift at 200A discharge, so the cells seem well matched. I will do a full discharge capacity test tomorrow, and log it all for a nice graph.