BC RV Camping Forum

Hey. Just got back from a 5 day camping trip which was all dry camping. Our travel trailer has two large 6 volt batteries which lasted us the whole trip. After driving home the batteries showed very little gain from charging off the truck. So my question is ouldint the batteries charge quite quickly off the truck?? I checked and do have voltage output at the trailer plug. The fuse going to the trailer charging harness from the factory is a 40 amp so I figure there should be lots of current there for charging. Does anyone one what amperage thier should be at the plug while driving?

Thank you!!

Was the fuse on the truck side or in the trailer?

It doesn't sound like you have any issues, this is normal... The 7 pin harness on your vehicle will not supply more than a few amps of charging current to the trailers batteries while driving, which won't amount to much of a charge being put back into the trailers batteries (especially after 5 days of use). The wire size is too small and the wire run is far too long to supply a decent current without overheating the wiring.

As a comparison..... My 6v's were at roughly 50% SOC yesterday when we left Shuswap. With 200w of solar on the roof of the trailer in full sun all day, and roughly 4 hrs driving time I still wasn't fully charged when we arrived home, and I did not expect it to be. I plugged the trailer into shore power at around 8pm yesterday and as of 8:40am the batteries are reading 90% SOC (my controller only reads in 10% increments). They probably won't read 100% until later today.

The problem with engine charging on our class C is voltage.  There were a couple of poor connectors and too long of a wire from engine to house batteries causing a drop of more than a volt.  Lower voltage can’t push as much current into the batteries.

A 100 watt solar panel solved all our charging problems.  The batteries never go below 80% charge.