Does D2-50 115A aternator survive 60A constant charge on low 1200rpm

[CaptainRivet]

Hi all,
does the standard D2-50 Mitsubishi 115A alternator survive constant 60A charge on low rpm like 1200RPM?
Reason i ask is i often operate the engine on low RPMs.
I have 2 new overpowered D2-50 instead 2x 20hp in my 40ft Lavezzi, motoring 6kn in calm or 8kn motor sailing is 1200-1400rpm on one engine. Have 2x 30A Victron DC to DC Charger=60A charge connected to a 300AH starter lead (new old hybrid lead house and starter, only used as stater now) each hull to charge 840AH Lifepo4 house. So if i use only 1 engine one alternator will charge the starter lead and 2 x 30A DC to DC Victron charger on low 1200rpms, if i use both its still 60A charge but shared between 2 alternators. This is due to both starter batteries each hull are connected together via victron cytrix to be charged as soon as one alternator charges, does not matter if BB or STB or both. So also both DC to DC charger start charging if one alternator is running.

[ben373]

I am using a 40 amp dc to dc which actually draws 50 amps from the alternator. Have charged for hours.

At 50 amps the alternator gets to 65C at 95 amps it was getting to 105C

Hope that helps. I understand they also have thermal regulation.

[CaptainRivet]

Originally Posted by ben373

I am using a 40 amp dc to dc which actually draws 50 amps from the alternator. Have charged for hours.

At 50 amps the alternator gets to 65C at 95 amps it was getting to 105C

Hope that helps. I understand they also have thermal regulation.

Thanks. A standard 115A alternator is normally good for continuous output around 50% of its rating, so 60A.
And what you stated sounds thats roughly correct. 105C is by far to much, around 80C max is healthy, so assume around 60-70A is max continous load it can do longterm...