Starcraft RV Owners Forum

westend wrote:The thing is, the12V draw from the batteries in the trailers original layout can be handled by a 10 AWG wire without too much drop in voltage. The draw of the inverter, though, is many times greater and you will need 4-0 cable from the batteries for powering all the AC outlets without experiencing a big voltage drop. It's better to locate the inverter close to the batteries and run 12AWG for the AC distribution back to a transfer swutch or rear located subpanel. Alternatively, you could use your shore power cord and plug directly into a forward located inverter. In that use, you should switch off your charging converter and make sure your appliances like AC, water heater, and fridge are all off. Another alternative is to relocate batteries to the rear.

FWIW, I have 5 batteries in two banks all located inside the trailer, all within a few feet of the inverter and converter. I use one vented battery box and have 3 AGM batteries in a separate compartment.

Good luck with your project.

Excellent information!

I think you convinced me. I will mount the inverter up front as I have a space. I will then run the 12AWG back to where the converter is located and install a transfer switch.

I need to get this rig out of storage so I can start!

The thing is, the12V draw from the batteries in the trailers original layout can be handled by a 10 AWG wire without too much drop in voltage. The draw of the inverter, though, is many times greater and you will need 4-0 cable from the batteries for powering all the AC outlets without experiencing a big voltage drop. It's better to locate the inverter close to the batteries and run 12AWG for the AC distribution back to a transfer swutch or rear located subpanel. Alternatively, you could use your shore power cord and plug directly into a forward located inverter. In that use, you should switch off your charging converter and make sure your appliances like AC, water heater, and fridge are all off. Another alternative is to relocate batteries to the rear.

FWIW, I have 5 batteries in two banks all located inside the trailer, all within a few feet of the inverter and converter. I use one vented battery box and have 3 AGM batteries in a separate compartment.

Good luck with your project.

CenOhio wrote:I'm thinking that voltage drop across a given distance is higher at 12vdc than it is at the same distance at 120vac. That's why you want the inverter as close to your battery as you can. Somebody will be along and add or correct me if I got it wrong.

I agree with this concept, but just curious why starcraft would install the batteries so far away from the converter from the factory. How do they overcome the voltage drop in that design?

If you go forward with this, be sure to document it and show us what you did.

Due to the voltage drop of 12V circuits, the gauge of wire gets pretty large due to the distance.

Since your batteries are 16 feet away from your converter, that is a good indication that there are probably some pretty large size wires connecting the two.

I wouldn't be surprised though if the manufacturer went cheap on the wires and as a result your 12V circuit will have lower voltage at the converter than it should.

If you were going to add an inverter at the same distance, you may want to consider replacing the wire.

I think that is right as well. From the factory my trailer is designed with the batteries up front and the converter in the rear, 16 feat apart.

Wouldn't the same principles apply here?

If so, how do they get away from such a long 12v run and make it work?

I'm thinking that voltage drop across a given distance is higher at 12vdc than it is at the same distance at 120vac. That's why you want the inverter as close to your battery as you can. Somebody will be along and add or correct me if I got it wrong.

I have a 16RB with the batteries located on the A-frame at the front and more shore power connection and convertor at the rear of the Rig.

I would like to add an inverter to provide power to the outlets when not connected to shore power.

Anybody have any recommendations on how to make this modification? Ideally, I would like to locate the inverter in the back near the convertor to easily tie into the convertor circuitry for the 120V outlets. This will also allow me to easily install an ATS so when shore power is connected, the inverter is turned off. Additionally, I would like to by-pass the A/C circuit so that the A/C is disabled when on inverter power.

I understand that inverters should be located as closely to the battery as possible due to voltage drop. My confusion is, wouldn't the connection from the battery to the converter experience the same voltage drop problem? If so, can't the same wiring that supplies power from the batteries to the converter be used to tie in the inverter in the back?

All help is appreciated.