Battery Charging Question....

[SilverLining]

Should there be any concerns over operating an onboard AC charger(Guest 2 stage, 3 bank 30amp) while the engines(200HP OX66) are running and also charging the batteries? The onboard charger floats at 13.6V. Goal would be to quickly bring the deep cycle house battery up after using downriggers, etc.

Current normal configuration is S/B engine charges its start battery + the house battery and the port engine charges its start battery. Really don't want to change the physical wiring set-up.

 

[seasick]

I wouldn't do it. Each charging system determines the state of charge by measuring the battery voltage. When you run both chargers, each charger is not seeing the battery voltage but rather the charging voltage of the other charger. That will confuse one or both chargers. The result could be under charging or over charging or worse.

 

[Grog]

I wouldn't do it, in theory the charger should back off when the motor supplies 14V but one glitch can fry something. Also if the battery is heavily drained you don't want to over do the charging, the battery can cook and/or boil off too much fluid.

 

[BobP]

For the benefit of your (expensive) motor, you don't want to parallel another DC feed to it.

 

[SilverLining]

Thanks for the input.....that's exactly the advice I needed. Will try to approach this issue some other way.

 

[NOTHING ELSE MATTERS]

Wait a minute, when i'm at the dock connected to shore power i always have my battery charger on. That said, i can't start my motors at this moment ? Do i have to disconnect the shore power first? I never done that and never had a charging or battery problem. BTW, i never remove my batteries from the boat when is in storage, just disconnected.

 

[Grog]

It's not that you can't but I don't think it's worth tempting.

 

[BobP]

Nothing Esle, I did the same thing, forgot charger was on, shut motor off right away when I realized it, nothing happpened, all I 'm saying that shouldn't be the norm, and I don't see why anyone needs to do it.

Unless Yamaha answers in writing the question, is it OK....?.

I bet they say "not recommended".