Using pro-power inverter

[Doug S]

Hi, I’m aware of the practical and beneficial implications of using DC to DC converters to charge a list of batteries while we’re driving down the road. My 2023 Ford F250 has a built-in 2 kW isolated inverter. It would seem to be very simple to just take the output of that inverter that’s in the rear of the bed and connect it to the shore input power and do the same thing that the DC to DC would do in a much simpler fashion. Typically you could do this with a 14 gauge three wire and initially it could be nothing more than an extension cord but eventually, of course it could be integrated more professionally. Is anyone doing this?

[Snackchaser]

Doug,

It’s certainly possible, but less efficient.  There are power losses when inverting dc to ac, and when converting ac to dc, and you would be doing both.  For example; say the inverter and charger were each 90% efficient, then you would have a collective 80% efficiency (actually somewhat less if you do the math).   Your modern equipment is probably more efficient than that, but you get my point.  I’d also check the Duty Cycle of the Ford’s inverter to assure it’s rated for continuous operation.

Cheers!  Geoff

[Doug S]

Geoff, Interesting point - Since the inverter is tied to a separate alternator and battery combination it is equivalent to a DC-DC converter in energy loss, and with much lower current and higher voltage to connect to shore power I wouldn’t guess that the efficiency is much different. I checked, and the inverter is rated for continuous duty- it could be a nice surprise. 

[Snackchaser]

Sounds like a great feature on the truck!  If I understand correctly, it has a separate alternator, etc.  Well then, I'd dissmiss any efficiency losses because it's like the source generator, and we don't consider those efficiencies!  

In fact you may gain efficiency due to the higher voltage, and less voltage drop from the wire.  Many DC to DC chargers suffer from voltage drop, which is effieceny loss, due to long wire runs with undersized wire. 

Cheers!  Geoff

[Doug S]

Exactly Geoff, I think for now I’ll try it with the  shore power plug in and see how it goes.