Power fades away very quickly - with New Batteries

[nnmsgst]

Originally Posted by Sergio

Are you tapping the 2 batteries on the driver's side for accessories/lights?

If so that creates an imbalance that is hard for the charging system to overcome.

They are both the ones on the drivers side.... but I'm just now starting to learn about how the wiring for lighting and accessories work.

[Sergio]

The SOC of the entire pack is equal to the lowest SOC of any individual battery.

When You discharge a couple of batteries more than the others, You create a charging imbalance.

Since the charging system charges a single 48v pack (not individual batteries), the batteries that had a higher SOC will literally boil while the batteries with a lower SOC might not reach their full charge.

You need to discontinue using those 2 batteries for accessories and get a 48v->12v reducer.

You can also try to do a few dV/dT charging cycles by forcing an OBC reset.

All You have to do is disconnect the pack negative for more than 10 minutes.

The next time You charge the batteries, the OBC will run another "baseline" analysis which uses a different algorithm.

Let that charging cycle finish and check the voltages on the batteries again, if they are still far apart, disconnect the pack negative for more than 10 minutes and repeat the process.

[nnmsgst]

Originally Posted by Sergio

The SOC of the entire pack is equal to the lowest SOC of any individual battery.

When You discharge a couple of batteries more than the others, You create a charging imbalance.

Since the charging system charges a single 48v pack (not individual batteries), the batteries that had a higher SOC will literally boil while the batteries with a lower SOC might not reach their full charge.

You need to discontinue using those 2 batteries for accessories and get a 48v->12v reducer.

You can also try to do a few dV/dT charging cycles by forcing an OBC reset.

All You have to do is disconnect the pack negative for more than 10 minutes.

The next time You charge the batteries, the OBC will run another "baseline" analysis which uses a different algorithm.

Let that charging cycle finish and check the voltages on the batteries again, if they are still far apart, disconnect the pack negative for more than 10 minutes and repeat the process.

How do I tell if there's a 48>12 v reducer in place?

[Sergio]

Probably not due to your battery voltages.

That yellow wire with an inline fuse connected to positive post of battery #4 (battery #1 is pack positive) appears to be your lights connection to 16v.