Two alternator tied together

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Rogerh

Guru
Joined
Aug 27, 2013
Messages
724
Location
USA
Vessel Name
At Last
Vessel Make
1990 Jefferson 52 Marquessa
We are in the middle of a trip and I lost one of our start batteries for our 6V92s. In order to start the bad battery engine I moved the starter cable to the other engine's start battery. So now I have both alternators going to the same battery. I know it's not ideal but can l leave it like this for our last 8 hour run? Any chance of damage to alternator? Just a bandaid till we get home...
 
Not a problem at all. Both of my alternators are tied together 100% of the time.
 
One alt will do most of the work as the lower output V regulator will see the charge from the higher voltage regulator and not create more output.

No damage , but no faster charge either.
 
Thanks,that is what I thought but wanted to make sure.
 
No problemo...but it illustrates the flawed cable configuration in so many boats. The charge and load sides of the electrical system often share a common cable. In my boat it was the start cable from the battery to the starter.

If you can separate the charge from the load, you have better control over each. I send my alternator charge directly to my battery banks via dedicated cables. The loads are carried through separate cables to the distribution panels, busses and the starters. If one battery bank needs help, the other battery bank can be combined via switches to share the load. This does not combine the charging from the alternators which continue to provide their charges to their respective batteries.
 
I agree with the separate start and alternator cables. This is the way our previous boat was and it gives you more options when things come up. On my list to do for sure. Now just working our way home.
 

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