Another BMS question - using on a parallel bank

[oldmaninsaline]

Logic says this should work but reality says this is probably a really stupid question. I got a million of them. I'm in the middle of doing the R&D testing of the power station design and am looking to save weight, even a few pounds (and less components) might make a difference. Not to mention if I switch both batteries to a smart BMS, that's another 2 Bluetooth devices to keep track of.


2 12 volt lifepo4 batteries (I do not want to tear the cells apart to do this, they did a fine job of building the batteries), each with their own BMS. My question is this: Is it possible to use an 8s BMS on a paralleled pair of batteries?

I would think that the balancing would take longer to achieve if this setup were used but logically, I would think the BMS doesn't care provided the batteries charge at the same rate.

The manufacturer (seller) assures me that the two batteries were both from the same batch, made from the same lot of cells. In the end, it seems that good smart BMSs will cost (if I have to use one for each battery in the 2 battery bank) the same as another entire battery since I'm paying $260 for these batteries which for some reason really frustrates me.

 

[sunshine_eggo]

No.

An 8S BMS is for 8 cells in series.

BMS lead expected voltage:
1 to 2: 2.5-3.65 (cell 1)
2 to 3: 2.5-3.65 (cell 2)
3 to 4: 2.5-3.65 (cell 3)
4 to 5: 2.5-3.65 (cell 4)
5 to 6: 2.5-3.65 (cell 5)
6 to 7: 2.5-3.65 (cell 6)
7 to 8: 2.5-3.65 (cell 7)
8 to 9: 2.5-3.65 (cell 8)

You can clearly see that most if not all of your readings would be 0V because the BMS leads are not connected to the prior series cell.

 

[oldmaninsaline]

Thanks for clearing that up!