battery bank question

[t16j10]

i have a 25' proline w/ a 250 merc outboard rigged w/ basic electronics (vhf, radio, f/f, gps) and standard lights. i have 2 identical batteries (24m8-1000 ca) with a a/b/both/off battery switch. one battery went bad and needs to be replaced. i never used starting or house battery, i just alternated between batteries every other trip. can you tell me what is the suggested way to use your batteries and can you recommend a battery to replace my bad one (it does not hold a charge and the sides are soft)><br /> i recharge thru my motors alternator(no shore power)<br />thank you <br />tom

 

[magster65]

Re: battery bank question

I do what you do, switch back and forth between them to keep them from sitting without any use.

 

[Trent]

Re: battery bank question

Run it on both while underway. This will charge all batteries. When you stop switch to one battery operation. If you run the battery your using down you can switch to both for starting and re-charging.

 

[Solittle]

Re: battery bank question

Trent - I assume that you do realize that when you have both batteries connected that the stronger will attempt to charge the weaker which can lead to a "no start" if one is near complete discharge and the other has only a moderate charge. I try to keep both fully charged at home and run on one for half the trip and switch to the other for the way home. I would use both only in an emergency when both are quite low to hopefully get that extra oomph to get started. Even then I would switch to only one after I got started to get max juice from the alternator into one battery.

 

[Trent]

Re: battery bank question

SoLittle.. Not if your charging system is working. Guess I should also have added that you need to monitor your system. If you dont want to do that you can install Zenor diodes in the charging circuits to prevent what you worry about.

 

[Boatist]

Re: battery bank question

Tom<br />If you have had good service out of this setup then I would find a new battery close to the same. While this battery is bad I would not run it in both as bad battery will take all the charge and starting battery will get very little. Can actually run down you starting battery while running if bad enough. Watch your volt meter and make sure get at least 13.8 volts. Also if you happend to leave in both with engine off bad battery will run down starting battery leaving you dead in water. Constant charging a bad battery hard on alternator.<br /><br />If I under stand your set up you actually only run off of one battery. You don't have VHF, GPS, F/F, and cabin light on one battery, and Starter, Bildge Blower, Bildge Pump, Nav light, horn on the other battery.<br /><br />I really like to charge both batteries thru a battery isolator or battery combiner and not mess with the switch but if this has been working for you then no need to change anything.

 

[Arnold96]

Re: battery bank question

As for the battery to replace it with, I and many others have had good luck with most any battery made by Johnson Controls. They include the Autozone batteries and some at Wally World, and finally the Die Hard is again made by them. Stay away from most any battery made by Exide as they usually get business by being the low bid if you know what I mean. There are others, but the Johnson Control made batteries are well proven.