Battery low on my 2004 Rinker Captiva

[Dutchlarson]

Hi Guys,

I have an issue with my 2004 Rinker 232 Captiva. This is my first boat with 2 batteries, and it has a switch for Bat1, Batt2, Bat1+2 and OFF. Before the season started i placed new batteries wich are both Marine spec 80ah battery, same as i took out.

So i took the boat out several times, and i only used the switch on battery one, also while at anchor. No problems.

Today i went out on the lake, still everything ok, but on the way back my radio kept turning off. After that, i noticed my trim switch didnt function anymore, so i conlcuded the power was low (voltage meter was still showing 13,5V).

Back in the dock i switched to battery 2, but it was completely dead!!

When i switched back to battery 1 i still had almost no power. However when i switched to Bat 1+2 everyhting worked fine again.

So, my question... Am i doing something wrong? Do i need to turn the swicht on 1+2 when i take the boat out so they can charge both? Or is my alternator dead?

Your help will be much apriciated!

 

[tpenfield]

When the engine is running, you are best to have the battery switch set to both. That way they will both be getting a charge to what ever extend they need it. When at anchor, using electronics, etc. it is best to have the battery switch to either 1 or 2, but not both, so you don't inadvertently run down both batteries.

You did not say how long battery 2 went without any love from your switch position selection. However, your description of both batteries not keeping up a charge sounds like you have a problem that is draining the batteries.

Time to grab the multimeter and check a few things out.

 

[Dutchlarson]

Thanks for the advice. Battery 2 did not have any charge att all, since i stated using the boat. Altough it is a new battery, i never set the switch on 2 or 1+2, while at anchor or when running.

Altough i have a multimeter and i know how to check the voltage of the battery or the alternator, i wouldnt know how to check if something is draining the battery? Where should i start?

 

[dingbat]

Sounds like your batteries are setup as motor and house.
You ran the house battery flat which caused the radio ( typical house load) to go flat.

When you combined start and house together, the two batteries equalizer and you ended up with two 1/2 flat batteries, neither of which supported the load on their own.

Combing the two 1/2 batteries with 1+2 provided enough energy to support the load where individually they would not