I have to keep my batts warm in the winter... So my truck runs off and on throughout the day flying. I wired in a 6 gauge charging wires into the cab that I could hook my two chargers up to. Just have to make sure you don't let charger go for longer then a few minutes without engine running.
The highest I have tried on the setup is 15 amp 6s charge and works great. For the summer I got a quiet 4 stroke 2KW to run the PSs. However, most the time I bring the batts to the field charged and only have to do a few charges to make it it through the day.