Can you change the battery switch while the engine is running?
 

In article ,
ray lunder wrote:

The AmplePower people agitate for strict prohibition on this saying it
will smoke the diodes in your alternator. Is this true? What are you
supposed to do? Start the boat with the starting battery, let it run
for 10 minutes, turn the engine off and start it again with the house
batteries and charge them under way? What say all of you?


As you see, there are many answers, each of which is at least partially
correct.

Personally, the next time I make major mods to our battery banks, the
starting battery will be directly connected to the alternator, the house
banks connected to that battery with a simple on/off switch.

First time I saw that setup was on a charter boat. Dead simple: On when
motoring, off otherwise. The major mistake of course would be to leave
them connected as you drew the bank down, but fumble-fingers can't fry
the alternator.

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/

Can you change the battery switch while the engine is running?
 

In article ,
ray wrote:

Personally, the next time I make major mods to our battery banks, the
starting battery will be directly connected to the alternator, the house
banks connected to that battery with a simple on/off switch.

But this is advised against as well, if I understand your suggestion,
because to charge the house batteries you are charging in parallel- in
my case a 12v starting battery and 2, 6v 110ah golf cart type.
Whichever set is depleted drags the others down and both sets charge
at different rates with different curves. I don't think my setup is
all that uncommon for coastal cruisers.

Not a problem if they can stand the same nominal alternator voltage, as
they won't be paralleled for very long, all things considered. You might
get a momentary "bump" as the starting battery boosts the house at
first, but it'll be replaced almost immediately.

We also have solar dedicated to the house bank, so I hardly ever need to
charge that bank with the engine.

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/