Charging 4 Deep Cycle Batteries Running a Power Inverter with Fridge Plugged in While Traveling

Question:

I have a 5th wheel trailer with a full size residential refrigerator. The fridge is run from a 1800 watt power inverter and 4 group 31 deep cycle batteries. This setup is what keeps the unit running and cold while we drive to our destination. In order to allow the fridge to run more than 2.5 hours before the inverter shuts off due to low input voltage, I would like to charge the batteries from my truck. Currently I charge the system with the 7 pin plug but the charge controller in my 2018 f450 limits the charge rate to a max of 5 amps. My truck is set up with 2 batteries and 2 alternators with an available 370 amps of power on tap. How do I allow the truck to feed the system demands while I am driving?

asked by: Spencer K

Expert Reply:

What you can do is connect the batteries that power the inverter directly to the starter battery on the truck or even an alternator in your 2018 Ford F-450. Keep in mind though that when multiple batteries are connected together it takes a long time to charge all of them up.

Instead of using the batteries you could attach the inverter directly to one of the truck batteries so that it will get constant power without depleting the truck batteries. This will allow you to keep your 4 deep cycle batteries charged. Then you could have a sort of quick connect set up that will allow you to switch from being connected to the truck battery to the deep cycle batteries when you turn off the truck.

Connectors such as # BDW20047 would be great for this.

expert reply by: Michael H