Running 12v batteries in parallel with converter/charger

[Flood the Rink]

Hi All:

I've spent some time researching this site and others to no avail.

I have a new Yetti with a WFCO converter/charger. Right now I have only one battery hooked up but want to add another. I'll connect the two to run the batteries in parallel + to +, - to -.

My question is how would I hook the WFCO converter/charger to the set of batteries as it only has one set of wires?

Would I hook the positive wire to one battery and the negative wire to the other battery? Or hook to just one battery?

My take is I would do the first or maybe this is not even possible.

Any advice is appreciated.

Chris

[Hoey]

Flood,

I had a similar situation, adding a battery to an existing system. I just added the battery and tied it to the existing, i.e. pos to pos, neg to neg with heavy wire. No issues.

Do not go pos to neg, this will create a series circuit making it a 24v system with unpredicatable results.

[Flood the Rink]

Thanks Hoey:

Assume I already have the batteries wired in parallel. How would I hook up the one set of wires from the converter/charger?

[fishnowworknever]

The charger will see the batteries as one battery. I believe you can do + to one and - to the other...honestly I don't think it matters.

If you think about it, you already have the poles connected in parallel...even if you spliced the 2 + and - cables and connected the charger there it would be OK ( don't really do this obviously)

I would opt for + & - on the same battery, but that's just me.

[Ishikawa]

The charger will see the batteries as one battery. I believe you can do + to one and - to the other...honestly I don't think it matters.

If you think about it, you already have the poles connected in parallel...even if you spliced the 2 + and - cables and connected the charger there it would be OK ( don't really do this obviously)

I would opt for + & - on the same battery, but that's just me.

This is correct. Just google "charging 12v parallel batteries" for more detail :-) Make sure you wire correctly because if you mix the connections, harder to do on a parallel setup, you will melt your cable connections onto your posts like i once did haha.

[walleye34]

I put a switch in my ice castle. The switch lets me go from Bat 1, Bat 2, or both. I wired mine this way so I can isolate the battery and charger. I also have a master shut off switch now. My generator is only a 1700 watt unit and if my batteries were dead the charger turns on full charge mode and I cant run anything else like a coffee maker or microwave. This way I can shut the master swtich off so my charger does not turn on and draw from the generator when I use those things.

[jigginjim]

Done that on an old fishing boat. Got the wires crossed to a switch, melted all the wiring.

[Ishikawa]

That would suck! I was hooking my 24v setup to the onboard charger and luckily it only melted on the post connection. Needed to switch out one of the cables for a longer one and wasn't paying attention and accidentally closed the loop by wiring both + and - connections to their respective opposite on the other battery. That was one big pop lols.

[TruthWalleyes]

I have 3 12v hooked in parallel in my boat. Put the charger on 1 battery, it charges all 3.