Battery Suggestions

[mmwjr]

Originally Posted by AACoPD05

In post #9 I have a picture of my setup if that helps, albeit it is before I replaced my batteries with brand new ones. I rotated the switch from one to two to both and there was no increase in voltage to the house battery. Saturday I'll check the alternator and report back. It was my understanding that both charged when in the both position.

Both should change when the switch is in the both position however depending on the condition of the batteries this may be too much of a load for the alternator. Sourcing too much current can damage the alternator’s regulator circuit.

Looking at the picture in post #9 is why I said it looks like standard 2 battery wiring to a switch and recommend switching between batt 1 and batt 2 every other trip.

[AACoPD05]

Gotcha. When I checked it the other day I could see a rise in voltage on the cranking battery with the engine running (12.9). I was unable to get anything more than 11.8 on the house not matter which position (not off) I had the switch in with the engine running. Only time I could get it to move off 11.8 was when I plugged in the trickle charger. My gauge on the dash, for what its worth, reads around 13 (right in the center) with the engine on and at a fast idle.

[shrew]

Originally Posted by Phillbo

Put it on pos 1 to start and run (both batts are being charged)

How would Battery 2 be getting charged by the alternator when the battery isolator is isolating to battery 1??

The only way this could occur is if the battery switch were set to BOTH, which is not recommended for charging batteries.

An Automatic Charging Relay (ACR) would allow you to draw from the Start battery when started and running. Draw from the house battery when the engine is off and charge both banks when running.

[AACoPD05]

Just a little update.

I used a different multimeter yesterday to check everything again, the first one was older so I used a nice new Snapon one I have, including the alternator. I found that with the boat off and cold before doing anything the cranking battery is showing 12.4v, the house is 12.2v. Running at 1500rpm the cranking battery is showing 13.9v and the house still shows 12.2v, no matter what position the switch is in. Off the back of the alternator running at 1500rpm I'm getting 14.4v output. So the alternator seems to be doing its job ok and is charging at least one battery.

When looking at my batteries, see post #9, I have two positive cables coming off the cranking battery that are going to the switch. The negative from the cranking goes to the negative of the house battery. There is a positive cable coming off the house that goes off behind the engine to some place I haven't figured out. There is a positive coming from behind the motor to the switch. So I'm guessing they house battery may not be tied to the switch at all, it certainly doesn't seem to be tied to the alternator as it never has a rise in voltage with the motor running.

Last the trickle charger is a marine charger.

[mmwjr]

I agree it doesn’t sound the the house battery goes to the switch hence no alternator connection. Being the boat is a 2200 what type of house load do you have? I wouldn’t expect there to be much on this model.

[AACoPD05]

I would agree but just off the top of my head I'd imagine the fresh water tank pump for the rear shower, the radio (UHF and stereo), bilge pump, lights, basically anything controlled by the dash. I know my bilge is hot all the time no matter what position the switch is in

[mmwjr]

When you say bilge is hot all the time are you talking about the float switch which should always be hot or the helm switch which should be wired through the battery switch? Definitely seems like a PO retired things. If it were me I would retire so the house battery is on the battery switch and then run as I do with every other trip switched between batt 1 and batt 2, never been an issue for me with 3 different boats.

[AACoPD05]

Correct, the float switch for the bilge is hot at all times, even with the switch (both dash and battery) off it will still come one as needed such as after a rain storm. The dash switch will also turn it on on demand. I'm thinking you're correct that something is wired wrong, espically since its not charging the one battery. I guess my first place to start is at the switch to see what exactly is wired to which position, then go from there.

[AACoPD05]

Success! I took the switch apart and found both positive cables were going to the positive post of the cranking battery (position 1 and 2) and none were going to the house. So I took one cable off the cranking battery and hooked it to the positive on the house, now both batteries charge when the switch is on both. When I installed these two new batteries I hooked them up just the way the previous owner had them so who knows how long it had been wrong but its sorted out now!