Running engine and charging at the same time??

[waterinthefuel]

Sounds odd, but very possible on a houseboat. We own one, and the 125 Mariner wasn't charging. We have since changed out (which actually had visably cooked from the inside out) the stator and she's a steady 14volts at all speeds. Before we had to use the generator to operate the onboard battery charger. Here is my question...<br /><br />Is it safe to charge the batteries (two 12 volt batteries hooked together in parallel) and run the engine at the same time? We may have done this, but the goofballs who owned this boat before us could have been the ones who did it, and it just never charged prior to us realizing that we were doublecharging it, and possible cooking something.

 

[Clams Canino]

Re: Running engine and charging at the same time??

You can charge two batteries in paralell, BUT if they are really low and you run the engine fast, they may look too much like a dead short and pop the rectifier diodes. (even 1 bat can do that sometimes)<br /><br />I think there is a high output stator and rectifier available for that motor. Rapair would know.<br /><br />I would think that a small generator for charging batteries is better in the long run, for the life of the outboard.<br /><br />-W

 

[Solittle]

Re: Running engine and charging at the same time??

Two or ten batteries connected in parallel still put out 12 volts so you will not be double charging. Running with batteries connected in parallel is not a good idea. The one with the higher charge will feed the lower until both are in equalibrium. Thus if one is fully charged and one drained you may wind up with not enough juice to start your motor from either.<br /><br />An outboard alternator is good for topping off one battery at a time but usually does not put out enough juice to do a good job charging both at the same time. I have a master switch. I start with both batteries connected in parallel - then I switch to charging one on the way out and switching to the other on the way back.