Well I did. I never charged the batteries through the alternator nor an extension cable; only through solar panels.
I did it as a prolonged test for myself to see if it actually could be done. Having traveled now some 40.000 miles with XP1 and XP2, I always had enough power for the main requirements:
1: Run the motor for the hydraulics
2: Fridge -this fridge has been running 24/7
3: Lights (high efficiency LED)
4: Hot water and air
5: Cooking (using the very efficient diesel cooker from Webasto)
6: TV/ DVD (yup I know, but living and working out of the camper does sometimes get boring)
7: Toilet
Couldn't always run the microwave which does suck up a lot of juice, but I never ran out of power during my test. I came close though.
On this version I had 3 panels at 110 watts each with 420 amps of battery power.
The efficient use of power is due to the choice of appliances and lights. Not all LEDs are the same. The ones I use are the only ones with a 75 degree light angle and produce a “real” light feel. You never know that they are LEDs when they are on. Guess you get what you pay for. And for those you pay…
Using the Webasto heater allows me a constant hot water supply and an incredibly efficient warm air heater to run.
The unit sucks between 1 and 3 amps when in use and doesn’t cycle very often.
Just thought I'd share my experiences
