HELP!!! Dead port side batteries

[Jason Herbert]

We replaced the port side batteries yesterday in our 2004 Sundancer 420 when we couldn’t get the motor to turn over. We woke up this morning to dead batteries again and no power to the lights. It was plugged into shore power all day/night. I’m thinking it’s a bad battery charger. Any thoughts are appreciated. Thank you!

 

[Pirate Lady]

Do not trust that battery. I have got bad brand new batteries. Don’t assume it’s good.

 

[Hoplite808]

Easy way to test is put a volt meter on the battery while it’s supposed to be charging. If the charger is working then the voltage should be 12-13 volts. Second concern, what is draining the battery if it’s not charging. If the battery switch was off the only thing still on should be the bilge pump. That shouldn’t drain the battery overnight unless your boat is sinking. If the Battery switch was left on what load was on it to kill it? We’re the lights left on all night? I’d be concerned about an excessive power drain.

 

[Jason Herbert]

Easy way to test is put a volt meter on the battery while it’s supposed to de charging. If the charger is working then the voltage should be 12-13 volts. Second concern, what is draining the battery if it’s not charging. If the battery switch was off the only thing still on should be the bilge pump. That shouldn’t drain the battery overnight unless your boat is sinking. If the Battery switch was left on what load was on it to kill it? We’re the lights left on all night? I’d be concerned about an excessive power drain.

The battery switch wasn’t off because we stayed on the boat last night. I found the battery charger and noticed that it was reading 0 so I’m not sure that it’s working.

 

[Hoplite808]

If it is reading zero then it is definitely not working. You did remember to turn on the converter switch on your AC panel for it to work, correct?

 

[Jason Herbert]

If it is reading zero then it is definitely not working. You did remember to turn on the converter switch on your AC panel for it to work, correct?

Yes it is on.

 

[Hoplite808]

Yes it is on.

Definitely sounds like your charger has quit. Time for a replacement one. In the meantime you could plug the battery into a regular charger to recharge it. Just make sure it’s ignition proof if you’re going to leave it in the engine compartment.