Battery Replacement - Where to connect positive

I've been prepping for 4th of July trip for awhile. I needed to change batteries.

I took a few good pics of the battery bay before disconnection, but I'm not clear on the second 12V positive terminal.

One positive cable (Battery 1) is going to the hydraulic motor. I didn't disconnection that one.

I have another positive cable that I did remove but I can't figure out where it goes.

Does the second positive cable (Battery 2) simply go to the positive terminal of Battery 1? (This would be in parallel from a schematic standpoint but the wiring schematic only shows one battery).

This would make sense to allow maximum amperage to the hydraulic motor.

Any help would be appreciated.

Thank you,

Tim
2007 Hilo 24T

Yes the batteries are connected in parallel. I'd send you a picture of mine but I have all kinds of hillbilly engineering going on and it would just confuse the issue...

If you get down to Sacramento, Battery Bill's can get you an exact replacement 100ah sealed battery for a good price. It's where I got mine

Thanks for the quick response. I sincerely appreciate it.

Tim, why don't you post the pictures you took of the "before" setup. I'm having trouble understanding your "two positive cable situation". It may well be due to having two batteries in parallel, since the HiLos came with only one battery OEM. But it would help to make sure.

My trailer has only ONE cable that goes from a positive battery post to the trailer. ONE cable from a negative battery post to the trailer too. But, like others, I've installed a second battery, so, I have one additional cable that ties the two positive battery posts together and another that ties the two negative posts together. If you connect yours that way, you should be fine.

- Jack

I thought mine came with two batteries from the factory, guess I learned something today. Anyway, I really like this type of dual post battery.

That's hooked up similar to mine, but mine is even more confusing due to connections for solar, a small water pump to fill the fresh water tank, and a battery maintainer. The battery with the hold down over it was the OEM position. The other is an add on. Having the two on board causes the compartment to swell on the sides in your setup (which is not a problem).

You've also done what I did - hooked the positive trailer cable to one of the batteries and the negative trailer cable to the other battery. You don't HAVE to do this, but it minimizes the small effect of electrical resistance in the cables that tie the two batteries together.

- Jack

I'm having a hard time uploading pics.

I guess it worked. Mine looks pretty similar to pjriss.

In mine you can see the positive on the right battery going to the hydraulic pump.

The positive on the left battery goes....?

to the positive on the right battery so they are in parallel?

It makes sense but I can't see it in the photo.

buttecreekwoody said:

The positive on the left battery goes....?

to the positive on the right battery so they are in parallel?

It makes sense but I can't see it in the photo.

Click to expand...

That would be my guess.

Oh hey Jack, I have a pump to fill the fresh water tank too!

Tim, I'm having trouble making sense of your original connections, too. Did it all work at one time?

Yes, the positive on the right battery seems to be the trailer positive cable. And, the positive cable on the left battery should be connected to the right battery positive post, but I don't see that connection either. I wonder if it was disconnected?

The heavy black negative cable on the right battery appears to be the negative cable to the trailer. There is a second cable attached to the secondary negative post that looks like it runs to the negative post of the left battery, which it should if they are in parallel.

Then, you have two smaller gauge wires, one positive and one negative. I can see the negative one is attached to the negative secondary post of the right battery, and that's fine. The red wire though looks like it MAY be connected (under all that corrosion) to a tab that is attached to the right positive secondary post - if so, that's also fine.

The only thing I see that puzzles me is the second positive cable from the left battery. It SHOULD go to the right positive post (probably the secondary terminal), when you install the new batteries.

Basically, any positive cable that is coming from the trailer needs to go to a positive battery post. The negative trailer cables need to go to a negative post. Then, you SHOULD have two remaining cables, that are fairly short and that are NOT connected to anything if you haven't installed the batteries yet. Those two connect the batteries together - positive to positive and negative to negative.

I hope this makes sense?

- Jack

Thanks for everyone's help and comments.

At just before sundown, I disconnected the shore power and the lights stayed on!

I was so happy I went to the hydraulic motor actuator and successfully lifted the top off its seat!

Tomorrow is the big test when I connect the trailer and see if the brakes work.

I replaced them. 15 Y/O plus I moved the trailer last time with 2 brakes locked, I ended up clipping the wire....yeah...the safety pin was out.

Thanks again!