installing a 2nd house battery

[ridahog]

My new 5th wheel only came with one battery and I would like to add a 2nd. I think I know how to install the 2nd battery, but just want to make sure so I'm asking you electricians out there if this is correct.

First make sure that the 2nd battery is identical to the 1st battery (Same Volts and Amp output). I'm assuming the battery in my 5th wheel is new, but this is an assumption. My 5th wheel is a 2012 so I'm not wanting to spend the extra money for two batteries.

1. Turn off disconnect to batteries

2. Run a short cable from the positive of 1st battery to the positive on the 2nd battery.

3. Remove negative cable from 1st battery and connect it to negative on 2nd battery.

4. Run a short cable from negative on 1st battery to the negative on 2nd battery.

5. Remove the converter charging cable on the negative of 1st battery and move it over to the negative on the 2nd battery.

6. Turn power back on quick disconnect switch.

Does this sound right for Parallel as I only want to increase my amp hours.

Thanks in advance

[wa8yxm]

Originally Posted by ridahog

Does this sound right for Parallel as I only want to increase my amp hours.

Thanks in advance

Sounds a bit more complex than needed.. Try this.

I won't argue with "identical battery"

To connect additional battery.

1: Remove NEGATIVE (Chassis ground) cable from existing battery
2: Connect positive on new battery to existing positive
3: Connect negative on new to existing, leave nut loose on new battery
4: Connect Negative (Chassis ground) to new battery and tighten.

No need to disable or unhook anything other than the negative (Chassis ground) as this "Disconnects" everything else.

Re: Master battery disconnnect.. If you have one turn it off before starting, and back on when done.

[ridahog]

Since my first battery is enclosed and vented through the front of the 5er via a small hose and from what I understand underneath the battery box (haven't confirmed this though). Do you think if I bought a 2nd box and removed the tube on the box and attached it to the 2nd battery and than jumped both boxes with another tube would this vent properly? I'm thinking the air would flow from the outside vent to the second battery box and than come up through the other tube to the other battery box that has the vent at the bottom. Might be over complicating this but want proper venting since this is below my bedroom.

[Cat320]

JMHO, but if you have one good deep cycle battery and will not dry camp, you only need one battery.

[RJay]

There are two things I would do. Turn off your converter before you disconnect it. And when it comes time to connect the batteries to the 5'er I would connect the positive lead from the 5'er to the first battery and the negative lead to the second battery. You could also do this the other way around, the point is that each house lead should be connected to a different battery. The converter should be connected the same way. Turn your converter back on only after it's reconnected.

[Paul R. Haller]

Please use an adequate wire size to interconnect the batteries. I do not know what size wire you currently have for + and - wires but use wires at least that big or larger. Personally, I use 4/0 cables for all battery connections. If you use too small a wire you will never actually see any value to adding another battery. You can contact any welding supply for large cable and heavy duty lugs.
-Paul R. Haller-