Also, any idea why my pictures started linking instead of showing up?

 

Figured I should add what my wire size is. I've got 10' of 12ga wire running from the battery to my lights. My lights should be drawing 11.6 amps. Is it possible I need to go up to 10ga wire, and that the 12ga is restricting voltage?

If that is the case, will I be ok to run with 12ga wire this weekend for one night?

 

Hopefully Dead Cell will chime in, but I think that a fully charged 12v battery should test something like 12.86 volts. Have you checked the water in your battery? Can't help you with the wire size question.

 

Mine test above 13.1 fully charged with no load normally, I had a bad battery other weekend that was almost brand new and only showed 11.8 volts when took off charger dropped to below 10 volts, was (1) of (3) for my 36 volt troller and noticed troller ran slow when unhooked charger, had to make quick trip to autozone and buy a battery to fish that night...that one off shelf was 12.3 volts and hooked up with gennie and ran charger in the boat on way to ramp, was 13.1 when got to ramp same as other (2) batteries

 

I have a similar setup with my voltmeter wired in. However, my meter is on when nothing else is. After a charge mine is around 13 volts but as soon as I turn on anything that pulls current it drops to around 11.9-12.1. Just from personal experience I think those little voltmeters when wired in parallel are VERY sensitive to current changes. If I were you I would run them for a bit and use a manual voltmeter on the battery to see what kind of volts you have. Mine will read around 12 all night but as soon as I shut off the load and test the actual poles of the battery it's usually more like 12.5+ even after running it all night.

 

That's exactly the kind of help I was looking for. Thanks!

I was really hoping that the load on the battery was why it was reading low, and I'm sure mines doing exactly what yours is. The bad thing is I guess the voltmeter isn't really going to help me on determining how long I can stay on the water.

 

If it's unhooked up from everything then it should read right around 12.8 like payphone said, that's without any load on it. Once a load is hooked up it drops. if it's disconnected again then it should go back to where it is roughly? play around with a multimeter, those things are honestly your best friends.

 

#12 wire is good for 20amps. So your good there. im betting you got a cell going bad or is bad. Check your water levels. Charge it. Let it sit overnight and test at the terminals in the morning.

 

If the caps are removeable, you can buy a Hydrometer from any parts store and test each cell.

Check each cell, and if one cell has a 50pt variance between it and the others then you have a dropped cell and the battery is toast.

(I'm doubting it's a bad cell, but if it is it's a MFG defect and should be warrantied)

 

I fought this battle, finally found a page listing distance of wire, wire size, amp draw and voltage loss explaining my almost volt drop on freshly charged batteries.

I read my voltage at the battery and then my voltage on the feeder wires and found it to match my digital gauge, 11.8v as soon as I turn on my 10 50w lights.

I have 6ga wire running 22 feet. I need to switch lights to 24v but I just have no more room for batteries and I run my generator and Powermax's most of the time anyways to power the 120v lights on rear deck.