Excessive current on one battery bank

[Joe Perez]

Here we go again. Always something.
I have two house battery banks. Each bank consists of 2, 6v batteries in series. Both banks are identical. I noticed that with the engine running and all breakers off, one bank draws 2 amps. The second bank was drawing 60 amps! to the point where the post gets warm.
With engine off I believe I was still drawing 10 amps.
Any suggestions on what I should be looking for?
It’s important to note no wiring changes have been made. The problem just arose on its own.

 

[capta]

Sounds like you have a bad cell in battery bank 2.

 

[Don S/V ILLusion]

Or a bad shunt/ shunt connection on one side of the monitor.

 

[sailnoproblem]

I had the same problem. It was a bad cell in battery #2.

 

[Davidasailor26]

What are the banks, particularly the high draw bank, connected to? Are they strictly in parallel, being shared by the same loads?

 

[Joe Perez]

Or a bad shunt/ shunt connection on one side of the monitor.

Thx Don. I think if it was a bad shunt, it would just show a bad reading. However, the battery terminal on that bank gets warm telling me it’s actually drawing excessive current.

 

[heritage]

The first thing I would check are the battery #2 connections. Take every cable off their studs and visually inspect.