Increasing charge rate from TV to TC?

A larger wire to camper battery is your answer. :)

Find a liftgate plug, they are rated to 200amp, and can easily use 4 gauge wire.

I used 2ga from the truck's battery to the truck bed socket, then 4 gauge from there to the camper's battery.

The truck easily recharges the battery bank in the camper while driving. I've even idled the engine, and ran the inverter off that..

Probably a problem with the wire size from alternator to the TC batteries. I would recommend installing a #8 or larger wire from the alternator to the relay, then a 50 amp automatic reset circuit breaker, then to the connection at the camper. This also needs to be rated at 50 amps, then to the TC battery.

The alternator voltage should be about 0.5 volts higher than at the battery while charging. Once the battery is almost full, then the alternator senses the battery voltage, and drops it's output voltage to about 13.6 volts to avoid boiling out to much water from the truck engine batteries.

A relay like Grainger part #6C017 will carry all the amperage that you need, and has silver allow contacts, for almost 0 voltage drop across it.

Fred.

RJsfishin wrote:
If it makes you feel better, every Motor Home that was ever built has the full charged chassis battery charging in parallel w/ the 1/2 dead house batteries, and it works just fine. So forget the idea that the full charged battery is stopping the discharged batteries from charging, and instead look for the real problem,......like has been talked about above.
Also keep in mind that ALL RVs have a "propane" Fridge for a very good reason.
I ran a 12v compressor Fridge in a Cabin Cruiser boat for 12 yrs, so I know how bad they suck !

This /\ BAD choice for refrigerator... replace with one made to run on propane so you don't tear up your trucks alternator. As OP stated, his problem is he installed an electric compressor refrigerator. Solve for X, not Y.

• How fat the charge connection wires are, is crucial
• You need to make available through wire size the ability to pass 40 amperes when camper battery is low
• You need to run wire a direct shortest electrical path to do this
• My recommendation is to use TWO (6) six gauge wires, one positive, one negative
• Starting from the truck, connect positive 6 gauge to other wires on alternator output battery stud
• Run short length of wire to fender mounted (60) amp circuit breaker
• Make your 6 gauge ground connection at engine block or battery negative, no breaker needed
• Run positive 6 gauge wire inside hose sheath under truck for protection
• Use 60 amp rated ANDERSON POLE 2-WIRE CONNECTOR to make disconnect between truck and camper
• Continuing on, install a 2nd (60) amp circuit breaker at camper battery.

Using wire or parts smaller than this you are just wasting your time and money.

6 Gauge Cable, and connections right to your mailbox.

Auto parts store for hose. Slit the hose lengthwise if you have to, to stuff the wire into. Wrap with bands of electrical tape then use black cable ties to attach to underside of truck.

Use silicone sealant the whole danged tube if you have to to make an insulation bushing where positive 6 gauge wire passes through new hole in truck bed to Anderson Power Connector.

When choosing model of circuit breaker do not screw around with thimble sise stud breakers. Real breakers cost 20+ dollars each and have a reset you can trip making the circuit go dead when the camper is not on the truck.

Worth every cent and every single bead of sweat...

I believe you could do better with heavier wire from the truck to the TC, but not sure what you already have. Some have gone up to No. 2 for the positive and negative leads.

When you look at a wire circuit, each part of the circuit consumes some of the available voltage. This is voltage drop. A thin wire is more resistant than a thick one, so a thin wire has more voltage drop. That means less voltage available to charge through your converter, and run your fridge.

After a night, your battery is low, and those positive and negative charge lines are fully loaded from the truck alternator to your camper battery. Take your voltmeter, and see what the voltages across the two batteries is with the truck running. Compare the two voltage readings. Then take a long set of jumper cables and connect between the two batteries under the same conditions. Measure the voltages now. That is the improvement you could get with heavier cables.

If batteries are in parallel they should charge the same. OR
1. One battery has a shorted cell
2. Wire size is too small to TC battery
3. Voltage reg problem so not fully charging
4. Alternator problem