Batteries and vsr

[Fpdr1113]

Installed JL subs, speakers,amps, and upgraded to 3 group 31 house batteries, and Minkota on onboard 3 bank 30 amp charger.

I worry about the vsr allowing the house batteries to be charged by the stators while underway midday and causing premature failure of the charging stators.....since I plan to charge each night with the on board charger, should I disconnect the vsr?

 

[David Analog]

You need the boat stators charging the stereo batteries throughout the day so that you don't deplete the stereo bank inordinately low, and then go through more batteries.
Yes, there is a concern that after a long duration at rest, after deeply depleting the stereo bank, you would load the stators with a depleted stereo bank + the continued stereo operation + the boat operations.
However, if a VSR is doing its job correctly, it will remain 'open' if the charging system is not large enough to elevate and maintain the 'closed' voltage threshold. So that failsafe is built in. You can always supplement the VSR with a Blue Sea 5511e dual circuit switch so that you can exercise manual control whenever you wish, remove the VSR from the circuit when AC charging during storage, or bypass the VSR and combine in an emergency.
Sometimes what is healthy for the boat charging system and what is healthy for the batteries is in conflict. You don't want to cycle your battery(s) below 12.0 volts (apprx. 50% discharged). Adding a dedicated & switched volt meter to the stereo bank side can allow you to monitor status. Some VSRs have a LED status provision also.