Battery charging Question

[eatcustard]

When engine is cold the second battery charges at 13.75 volts, after 10 mins driving its down to 13.4 volts (no charge is being used, ie radio, lights etc)
Would that be the bushes going?

The battery holds charge at 12.7 volts over night, so no problems there and all earths look fine.

Thanks in advance

[kevtherev]

your battery is good so I would be taking a look at their condition sure

[Mocki]

question is, what is the main battery doing?

when two batterys are connected together, they will always equalise to the lowest battery voltage...fact.

i suspect the main battery is running at a lower voltage than the leisure battery, due to the drain put upon it from starting the van, and possibly its condition not being quite as good as the leisure battery, therefore the second battery is dropping in voltage due to the equalisation.

[eatcustard]

The main battery is old, so could be due to be replaced.

Will change it and look at bushed to be sure

Thanks for help