Hey all,

Does anyone know if both batteries charge regardless of where the battery switch is positioned?
This would be from the central jumper that plugs into the fusepanel under the rear seat on a 29.

I ask this because both batts were dead, so I started charging batt 1 with 10 amps.
After 30 minutes I turned off the charger, switched over to batt 2 and that battery had come to life.

Was wondering if both batteries are direct wired through the central jump plug as an "input" and the battery switch only works as "output" on the boat's systems.

Couldn't find any information on this.
This would be helpful to know, especially if the batt switch could be turned to "off" while both batts stay on a trickle charger using the jumper plug in.

Thanks.

Mark, I was thinking about your question and while I don't have the answer I believe I know how you could find out. You would need a volt meter. If you don't own one you could borrow one from an auto parts store.

Turn both switches to OFF. Check the voltage of each battery. Next, connect your batter charger to one of your batteries. Connect the volt meter to that same battery and note the increase in the voltage (I would think you would see at least an additional volt or more when the charger is connected). Now connect the volt meter to your other battery. Play with your switch positions until you see a spike in the voltage meter reading showing that you are seeing some charge voltage from your other battery. Am I making any sense? You could also attach the charger to the "jumper port" under the rear seat and explore if it connects to both batteries. The volt meter will show the increase over the batteries not being charged. I thought about trying all of this in my Fountain and I probably will. There is just no way of knowing if our boats are wired exactly the same - tho I would think so. Good luck with this.
Did you ever figure out why both of your batteries were flat?

Thanks Wes - yes that is my plan once I visit my boat probably Monday or Tuesday.
Mostly interested in how the jumper plug works in relation to the switch position; whether it is independent of the switch and direct wired, or is in sync with the switch.
Batts were dead just due to the boat being in storage for so long and not on a trickle charger.

I leave both battery switches in the OFF position and have a 1.25 amp "float" charger connected to each battery when the boat's in the garage. I've been thinking of buying a 1.5 watt solar panel that plugs into the cig lighter for when the boat's on the hook. Let me know what you come up with. Thursday looks like the day to be on the water with 75º+. We'll see!

You know I tried playing with this and when Im not in the boat both are off, when Im in the boat both are on. When Im charging the batteries which Ive done wonce i turn them back on.

I was thinking some more, and when I played around with mine and Im sure most set ups are the same I have one main battery per say that runs the engine and one that must be for accessories, so I have to have one on at all times to run. As far as charging in the winter I took them out full charge then put them away this spring they were at 95% and didnt even charge them again. I know some leave on tenders all year and not saying its a bad idea, but there is a cost associated with buying the tender and continuosly running juice to them.

I had to replace the battery charger in my 06 38 EC with duel batteries and duel battery switches. The battery charger is wired directly to the battery terminals, so most likely the bateries will charge regardless of the battery switch. If you want to confirm, just look at the posts on your battery and you should see a small 14 or 16 gauge wire (back for neg. red for pos.) connected to each post. You might be able to follow those leads back to the charger. My two cents.

Chargers should be connected directly to your battery/s, whether at the batteries themselves, or at the switch on the battery side , so they will charge regardless of battery switch position. (Same as your bilge pump)

Disconnect your battery (+)cables and measure for voltage at each cable end with the charger on and with switch at different positions for clarifications on what does what.

good point. I dont have an onboard charger but I have extra red and black wires for every battery I traced them to the back seat. I have one of those things there you plug jumper cables under theback seat and throw them over the side to either get a jump or charge the batteries. So you are right it would lead me to beleive they wouldnt have to be turned on to charge. The make sense thing would be that the system is set up to take charge anytime, but it will only allow charge to leave when the switches are on.

Update:

So the "jumper cable" has been plugged into the fuse panel now since Saturday.
The "charger" has been one of those "Battery Tender" units that charge batts with red light and show green light while on "maintenance or trickle" mode.
I left the battery switch on "1"...

After unplugging the charger, my handheld voltmeter shows 12.5 volt on the "jumper cable" connected to the fuse panel, whether the switch is on "1", "2", "Both", or "Off"...

So the Battery Tender charges both batteries regardless of switch position.

I left the tender on and the switch off to disarm the boat's systems...

Thanks for the advice guys, US1 Fountain is the daily winner....