Two Batteries

[RSHOOTER]

I am picking up a new Stern Drive Glastron boat in a couple of days. The Dealer installed a second battery with a switch for 1-2-Both-Off. The batteries have different amp hour capacities. After starting on 1 and then switching to Both for charging will this be a problem since the batteries are of different size? This is the procedure the Dealer recommended.
Thanks.

 

[Texasmark]

Re: Two Batteries

If you have batteries in parallel and are using one charger across the parallel combination, the battery with the lowest resistance (includes highest discharge) will get the larger amount of current. Over time, as it charges, it's resistance will increase (will consume less of the available current) and the other battery will get the majority of current.

This will go on till both are charged. Depending on several factors, when charging has terminated (more or less.....trickle), one may be at a slightly higher voltage than the other, but they both will be (no reason not to be) adequately charged.

Mark

 

[RSHOOTER]

Re: Two Batteries

Thanks Mark, I was thinking they should both be the same capacity as the charging is from the engines alternator. I guess that really doesn't matter. Appreciate your help.

 

[ricksrster]

Re: Two Batteries

 

[bruceb58]

Re: Two Batteries

Buy a battery combiner and you won't have to worry about putting the battery switch to the "both" position to charge both batteries at the same time.

Blue Sea makes a good one for around $70

 

[drewpster]

Re: Two Batteries

And the battle rages on!