battery drain

[skiMachine]

Is there a "rule" for how long the engine must run (at idle or higher rpm) to re-charge the battery from the power lost during starting? <br /><br />If it matters, this is for a 1984 3.7L Mercruiser.<br /><br />I ask because the last time I started the engine, the battery seemed a bit weak. Our boating behavior is pretty lazy, in that we typically run from the dock to a quiet cove where we anchor and sit for hours before returning to the dock.

 

[Dunaruna]

Re: battery drain

The only way to accurately measure what you are asking is with the aid of an amp meter.<br /><br />During the course of the day you will use xxx amps, the alternator will supply xxx amps. If you use more than the supply - the battery will slowly drain.<br /><br />You may be the perfect candidate for a small solar panel.<br /><br />Aldo