Battery Protect

[Esmerelda]

Perhaps a silly question, but...

Would there be any problems with a system where domestic and engine batteries were connected permanently in parallel, but the engine battery had a low voltage cut off device (such as Victron Battery Protect) so that it was isolated before it dropped too low to start the engine?

 

[halcyon]

Perhaps a silly question, but...

Would there be any problems with a system where domestic and engine batteries were connected permanently in parallel, but the engine battery had a low voltage cut off device (such as Victron Battery Protect) so that it was isolated before it dropped too low to start the engine?

One of the reasons for developing the VSR was to provide a separate supply for navigation electronics, to do what you are trying gives a lot of spikes and noise during engine start as the relay will drop during engine start, or you will have all the noise and low voltage problems if it has a drop out time delay.

Why not just fit another battery ?

Brian

 

[duncan99210]

Also a starter battery tends to be an automotive type, suitable for the short but high loads of engine starting but not designed to be deeply discharged, whilst the domestic batteries tend to be deep discharge types which are not best suited to the loads of engine starting.