Battery Switch Operation

[heritage]

I change the alternator output to different batteries with the engine running all the time. I think that the taboo comes from the fear of isolating the alternator from any battery and frying the diodes. The (very) old switches did not have a continuous contact feature when you turned from one battery to another, and there is always the chance that the switch could be turned to the "off" position.

 

[Don12364]

Having opened up a battery switch and seen the massive brass wiping connections which could quite possibly be corroded - and knowing that only a few milliseconds of open circuit is all it takes to destroy the alternator diodes, I prefer NOT TO TOUCH either of my battery switches whilst the engine is running - even at only tick over revs.

I just switch both on when I come aboard and they remain unmolested until we leave the boat.

Why tempt providence?