tmalcolm· Premium Member
2021 Crew Van AWD, EcoBoost, 148, HR, Adventure Package
Discussion Starter · #21 ·
Yea, too bad I can't select actual values. Though I suppose these are close enough. Per this chart, I think I would go with 12.0v low cutoff for the BP, restart at 13.0V. Agreed, it seems a long time between cutoff and restart.I think many (most?) BMS's have a low voltage disconnect. Based on the specs for my SOK's it does seem that it is intended as a failsafe and not as a normal operation control "Recommend low voltage disconnect: 11.2V - BMS discharge cut-off voltage: Around 10.4V - Reconnect Voltage:>11.6V " Probably not good for the battery to go below 11.2V often. So I guess some sort of cut off for the 12V loads might be a good idea if that was becomes a frequent event. Of course one would need some sort of data logging to know how oten the batteries were in that 10.4>111.2 range.
Looking at the specs, it does not look like the BP , it is sort of disappointing that there is just a choice of fixed settings where disconnect and reconnect are paired. None of which seem to play very well with the spes for SOK's.
If I was t chose 11.25V cut off, then it won't reconnect until 13.8V whereas the BMS is good to go at 11.6V
There is a 11.5V setting that reconnects at 12.8V so give up a little capacity to reduce reconnect voltage.
Where charging is by alternator (or shore power) it would seem these settings are leaving the system off muche longer that necessary. Never thought about any of this stuff before. Always good to RTFM.
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I'll use the Cerbo to also track and activate a buzzer before the cutoff to eliminate that period altogether.