Charging trailer batteries while driving

[Kirwin]

Battery charging

I have two 4D (380 Amp-hr capacity) batteries on my trailer. If I use the inverter to run the refridgerator on the road vice propane, (usefull in the Tidewater Virginia area due to tunnel restrictions on the use of propane), I am discharging about 35 amps on the battery bank. The refridgerator cycles on and off based on temperature so its not a constat draw. The charge line as installed by Dodge will maintain the batteries fully charged but will not recharge them in this mode according to my Link 1000. If I start out the trip with 50 amp-hrs discharged from the battery bank as long as the refridgerator is being supplied from the batteries, via the inverter, they will remain about the same. If I switch the refridgerator to propane they will slowly recharge at about 10 amps per hour. I do not use an isolator but do unplug the trailer connector at night if we stop on the road to isloate the trailers 12 volt system for the trucks. Hope this helps. Ken Irwin

 

[ACerf]

charging

I installed a solar panel on the my fiver. This allows the trailer to be charge whether you are pulling it with the truck or not. for example; I have an automatic vent fan in the bedroom. With the solar panel I can set the fan temp and it will come when the temp is reached. And the solar panels keep the batteries full.

We have dry camped for 8 days using just the solar panels. So why worry about using the truck to charge the batteries, when the sun is free!

 

[Bob V]

I recommend not using the isolator, the voltage drop through it will not fully charge the truck or trailer batteries. I recommend trying it like it is first, I have never had a problem with my batteries on the trailer, you will get a better charge on them with lower amps over a longer period anyway.

 

[jelag]

Most good 12 relays are rated at 40 amps... my trucks have a 10 gauge wire with a fuse from the battery to the trailer plug... . with a relay that switches it on..... we put the relay at the back... . and when the tail lights are on the relay is switched on... . we always pull with the lights on... .



When the lights go on the 12 v lead is hot, and when the lights are off the 12 lead is off..... or you could connect the relay under the hood to an ACC circuit...



Hope this helps... you might want to read the post about batteries in this section.....