Easy way to monitor 3rd battery voltage

Question

question

derrick thomas asked Nov 12, '22

Easy way to monitor 3rd battery voltage

Is there an easy way to monitor voltage on a 3rd battery? I already have 2 smart shunts...one monitors house bank and the aux input monitors midpoint voltage of the house bank. The second smart shunt monitors DC Loads and engine alternator current, aux input monitors engine batteries. I am hoping for a way to easily monitor the generator start battery voltage without spending the money for a 3rd smart shunt? I'm only interested in the voltage. I have a cerbo gx and hope to add the generator battery voltage to the gx for monitoring. Any ideas?

battery system voltage

1

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

kevgermany ♦♦ commented · Nov 13, 2022 at 05:57 AM

I think the only way is a third shunt, sorry

0 ·

Modifications Space

Node Red Space

Answer 1 · 2022-11-13T07:03:50Z

pwfarnell answered · Nov 13, 2022 at 07:03 AM

There is a solution with some downsides.

As you monitor the engine batteries voltage with a SmartShunt this means that the engine and house batteries share a common negative. Therefore, you can power the SmartShunt from the engine batteries, which would give and connect the aux to the generator start battery, but this does need the generator start battery to share a common negative with the other 2 batteries.

The downsides are you then have a permanent small current drain on the starter batteries and you will need to be aware of this cross connection if isolating either bank.

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

question