Battery question.

[MassillonBuckeye]

In the rear of my boat I have a cranking battery and a house battery. They were initially connected in Parallel but I disconnected the positive leads pretty early on because I didn't want my FF and livewell killing my starting battery. I left the negatives connected for the sake of a common ground? What I'm wondering is if connecting my charger to the house battery had any sort of charging effect on the cranking battery? I'm wondering because I haven't had to charge the cranking battery at all. Is it just the charging circuit on my motor keeping it juiced? It's output is supposed to be around 9a at WOT I assume, but I haven't really ran at WOT a whole lot. I installed a two bank charger tonight to run one bank up to the bow for the troller batteries. And I disconnected the common ground between the house and cranking battery during the process.

 

[Silvertip]

Re: Battery question.

You can safely charge the house battery as you show in the diagram and NO -- it has no effect whatsoever on the starting battery. Not knowing what engine you have we can't be certain about the state of charge on the starting battery but since the engine has electric start, it is very likely the engine charging system that is keeping it topped off as it should.. In the good old days when electric start first appeared, engines had no charging system so the battery needed to be charged using a plug-in type of charger. However, if the battery was of decent quality and capacity, many users went most of the boating season without the need to charge the battery. In the warmer areas where one could boat year around, obviously the battery needed charging periodically. In your case, the engine is doing its job.

 

[MassillonBuckeye]

Re: Battery question.

You can safely charge the house battery as you show in the diagram and NO -- it has no effect whatsoever on the starting battery. Not knowing what engine you have we can't be certain about the state of charge on the starting battery but since the engine has electric start, it is very likely the engine charging system that is keeping it topped off as it should.. In the good old days when electric start first appeared, engines had no charging system so the battery needed to be charged using a plug-in type of charger. However, if the battery was of decent quality and capacity, many users went most of the boating season without the need to charge the battery. In the warmer areas where one could boat year around, obviously the battery needed charging periodically. In your case, the engine is doing its job.

Its a 1979 70HP Merc.
Would you connect the grounds together like that?

 

[Bondo]

Re: Battery question.

Its a 1979 70HP Merc.
Would you connect the grounds together like that?

Ayuh,... It don't matter, as the Grounds all become common at the motor's block anyways...