Voltage monitor for SOK batteries

[corn18]

I was drunk ordering stuff off of Amazon the other night and bought one of these to monitor individual cell voltages on my 2xSOK 12V 206Ah LiFePO4 batteries wired in parallel:

https://www.amazon.com/gp/product/B07797N9BG/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I figured I had 8 cells and this monitors 8 cells so good to go! Not sure it's that simple now that I am looking at the 8S connector.

So, any way to monitor all 8 cells with just this one monitor? I think I need one for each battery, but thought I would ask.

And I know someone will ask. I am just curious what my cell voltages are. No other reason. If the SOK had a better BMS, I wouldn't need these.

 

[sunshine_eggo]

You need one per battery. The unit expects the cells to be in series.

It has a manually selected balancing function, but be advised it doesn't pull power from all connected cells, just the first two. Leaving it in place and on for months might create an imbalance between cells 1-2 and 3-4.

Rather than leave it connected full time, you might want to get a second harness and attach to the second battery. Simply move the unit back and forth between the two batteries when you want to know the cell voltages.

 

[corn18]

I messed around with wiring one monitor. I could get it to monitor 7 cells but not 8. So I just bought a second one. Mounted to top of case. At this point, I might as well get a JBD 200A BMS and swap them out. Maybe later.

 

[sunshine_eggo]

I messed around with wiring one monitor. I could get it to monitor 7 cells but not 8. So I just bought a second one. Mounted to top of case. At this point, I might as well get a JBD 200A BMS and swap them out. Maybe later.

Yep. If they were in series, it would work. Since they're in parallel, only 3 of the 4 cells in the second battery will show a proper voltage differential.

Remember to periodically activate the battery balance function.