Alternator overload?

[Preston Nash]

I had my coach in the shop for about a week to replace shocks.  When I picked it up, the coach batteries were at 12.4 volts.  I started the generator for the ride home, thinking the gen would take the load and not overload the alternator while the battery bank charged.  About 20 minutes into the drive, the voltage went from 13.8 to battery voltage.   I removed the alternator and took it to a reputable shop where it was rebuilt 2 1/2 years ago.  On inspection, he told me the stator was bad and it was clear that the alternator had been overloaded.  I don't clearly understand the way the generator and alternator work together to charge the batteries.  Any time the batteries are low, do I need to avoid driving until the batteries are fully charged by either shore power or the generator?  I thought I was taking care of my alternator, but apparently not. 

[David T. Richelderfer]

I found this using the search routine:

"Gene [Obie],

I think the 2nd to last paragraph in the BIRD Diesel 2 documentation addresses your concern;

'A Gen-Set Lockout is provided to isolate the batteries to prevent conflicts if both the converter/gen set and alternator are trying to charge the batteries at the same time. .....'

Steve [Huber]"


If I am interpreting the above comment correctly, it's telling me the engine's alternator charging takes precedence to charge both battery banks when both the engine and generator (or shore power) are engaged simultaneously.

So that is the reason why when the house batteries are low, the engine should not be engaged before charging the house batteries from either the generator or shore power for a brief period, say, 15 to 30 minutes.

[Preston Nash]

David,  I don't think I have the BIRD system, but I'm sure the same principle applies.  That's what I was trying to verify and your assistance is very helpful.  Thank you.