Parallel Battery Bank Question....

[kthrash]

So the dealer I purchased my 242 from installed two group 24 starting batteries in the boat, one for the house and one for the motors.. I want to install 2 group 27 batteries deep cycle in parallel for the house for extended run time for the radio, question is would it hurt the 1.8l starters to run the two group 24 batteries I have in parallel for the starting side? both batteries are 650 CCA, so that would be 1300 CCA in parallel..

 

[PaulyB]

Won't hurt, but I dont see why it is necessary....

 

[kthrash]

I just hate to have a brand new battery sitting in my garage not being used.. especially if it can help out on the boat..

 

[PaulyB]

Sell it on craiglist and recoup some money to pay for your house batteries.... There will really be no added benefit to having two starter batteries. There is not enough stuff on the starter circuit to warrant it.

 

[maboat]

Voltage pushes the current through a resistance. Current does not push it is drawn (or drained)

In other words, you could have a 10,000 amp battery bank and as long as its still 12 volts, your starters are going to draw the same amont of current as they normally do. Higher current capacity does not push or force more current into the circuit. It would require a change in the voltage and/or resistance in order to flow more current.

 

[David Analog]

It's odd that the dealer would install a starting/cranking type battery on the house bank. That should always be a deep cycle.

You can have two identical banks, starting and house, consisting of all deep cycle batteries, so that you can alternate their functions weekend to weekend in order to extend the longevity of the entire battery group.
But in your scenario the second starting battery adds nothing and hurts nothing. Just added ballast.

 

[MikeyL]

Sell it on craiglist and recoup some money to pay for your house batteries.... There will really be no added benefit to having two starter batteries. There is not enough stuff is on the starter circuit to warrant it.

2 additional items to consider:
1) The 2nd and totally unnecessary starting battery would take up important and needed storage space in that compartment.
2) The 2nd and totally unnecessary starting battery adds unnecessary weight to the boat.
Take @PaulyB's good advice !

Best Wishes, Mikey Lulejian - Lake Oconee, GA

 

[mgabsa]

Waste of money to add the battery configuration you described.

Install a battery charger (about a $130 upgrade) that way every time you go out you will start with a battery that is fully charged. Make sure the starter battery is not shared by the house battry that way you will know that no matter how long you stay out, your engines will start.