Leisure Batteries.

[CAPTAIN FANTASTIC]

I always start on the Red Flash and switch over to domestics after about 15 minutes. When the engine is warm and restarting later on I use the domestics to avoid going below to switch over again. It didn't do my Numaxs any harm.
I did try a VSR but it would not work and kept " chattering". Victron said it didn't like the differential in battery bank capacities so i now keep it simple.

My knowledge of electrics is minimal. I would much appreciate a bit of clarity: When the engine starts with the Master Switch in position 1 (assuming position 1 is the engine battery) and while the engine is running, the Master Switch is turned to position 2 (assuming position 2 is the domestic battery); momentarely, while the switch is moving from position 1 to 2, there will be no battery; is this likely to cause any damage to the alternator and/or diodes?

 

[VicS]

My knowledge of electrics is minimal. I would much appreciate a bit of clarity: When the engine starts with the Master Switch in position 1 (assuming position 1 is the engine battery) and while the engine is running, the Master Switch is turned to position 2 (assuming position 2 is the domestic battery); momentarely, while the switch is moving from position 1 to 2, there will be no battery; is this likely to cause any damage to the alternator and/or diodes?

It depends on the switch you have but with switches like this

in which you have the option of switching via the "both" or via the "off " position it is imperative that you switch via the "both" position if the engine is running,

If the layout of your switch is different with position 1 and position 2 next to each other I would assume it was a make before break type of switch But I would check it out.

Some switches have an automatic field disconnect facility

 

[CAPTAIN FANTASTIC]

It depends on the switch you have but with switches like this

in which you have the option of switching via the "both" or via the "off " position it is imperative that you switch via the "both" position if the engine is running,

If the layout of your switch is different with position 1 and position 2 next to each other I would assume it was a make before break type of switch But I would check it out.

Some switches have an automatic field disconnect facility

Many thanks for the reply. Yes, my battery switch is the same as you have shown; I will make sure it goes via "both".