It seems as if the batteries in my boat are not charging.... I just put two new ones in, ran the boat for maybe 3 weekends and now near dead again. I always turn them both off when docked, I do not have shore power the boat stays in the rack storage.
I've check all connections and appear to be in good order. Could my alternators not be charging my batteries when im running? Are there any signs I should look for our troubleshooting advice?
thanks in advance

Do you have voltage guages? If so what do they say? Should be around 14 volts when the motors are running. If not use a multi meter to test them. If that all shows as ok then look at your cables. They could be corroded. If you have only 12 volts when running or less then your alternator is not charging. This could be a bad alternator OR your "excite" wire is not getting voltage when the engine is running. You could also have a bad ground, ignition.........

Hope that helps a bit.

Jon

same thing happened to me.. i threw an alternator belt.. took me a while before i figured out to check the belts.

Get a meter that reads DC amps, and put it around a battery lead. See if it goes up when the engine is running. It should go up. Reading just the voltage, which requires a much cheaper meter, should go up also with the engine running.

Don`t forget that if you have a one wire alternator, you might have to rev. up the engine (1500-2000rpm) to get it to start charging.

Check for current drains from all wires that are connected directly to your batteries.

I had a Mercathode box go bad and drain my batteries. Check to make sure the bilge pumps are not running.

Did you run the boat??? or just idle around the marina?

I had two brand new Optima's poop out on me. After checking all the circuits I found that the amp to my stereo, which was connected directly to my batteries, was putting a constant drain on them. Disconnected the amp and no more problem.

If one of the batteries has a bad cell it will drain the other battery. Check them for voltage individually, check the voltage while running and see if it goes up and last but not least you can check for a draw by disconnecting one of the cables and using your meter in between the cables.

Thanks for the info. I do run the boat, no just moving around the marina. Im gonna hook up a voltage gague as recommended above and get a reading...
My amp IS ran directly to my battery.... I guess that cant help any thats for sure, Does it really draw enough power when turned off and sitting in the rack to drain out two batteries? I'll certanily disconnect. Thanks for all the info