2nd battery not charging

[stunod]

Hello again,<br /><br />I have a dual/1/2/both/switch<br />I bought two new batteries and installed them.<br />I tried # 1 and started the boat, then switched to # 2 and started up the boat....Great!<br /><br />1 week later...dead 2nd battery. I started the boat with the switch at "BOTH" and drove the boat for an hour. I switched back to #2 and boat doesn't start...STILL DEAD<br /><br />What gives???<br /><br />Thanks,<br />Lou

 

[russthemuss]

Re: 2nd battery not charging

They may be new. but they aint always charged! One hour wont do much if its flat flat.Take em out and charge them both and start over again.

 

[petryshyn]

Re: 2nd battery not charging

Is your charging system functioning? What is the voltage across the batteries while running? Most O/B charging systems are low output and will take a long time to charge 2 batteries...

 

[aeronutt29]

Re: 2nd battery not charging

In addition to the excellent advise to use a plug-in battery charger first, if you have two batteries that are significantly different ages, they will charge at different rates. I don't remember which order they go, but one will overcharge while the other undercharges. Set your switch to only run on the weaker battery after the motor is running to ensure that it is getting all available charge.

 

[Boatist]

Re: 2nd battery not charging

Lou<br />I think charging with an external charger is a good idea also, But have a couple of questions. What runs off the second battery and could it have been left on. Also I would check voltage on second battery with a volt meter. Battery may be ok and you just have a loose or poor gound wire. Make sure all wires for second battery are tight and connection to battery is clean and tight. also ground wire to engine does not have paint or something preventing a good connection. There are two types of switches make sure your's has a field disconnect or only switch with motor off, or you could blow your alternator.