I would be very careful using a third party DC charging device especially on the new Apple Macs with with the terraced cell lithium batteries!
I have a 2011 Mac Book Pro (pre-dates Apple's 2012 patent for terraced cell batteries) and I can use just about any type of third party charging device without negative consequences.
My wife as an early 2016 Mac Air; the first and only time we put that on a third party charger in the camper, the battery got VERY HOT in a matter of minutes. It was so warm I was concerned if we left there much longer, it would become a fire hazard due to an exploding battery...which newer Apple batteries have been known to do with third party chargers.
Apple terraced cell batteries manufactured the last 3 years or are proprietary batteries and only Apple authorized chargers are warranted or authorized for use. There is firmware embedded in Apple batteries in order to maintain charging cycle count and other information. I suspect the firmware tracks if an unauthorized charger is connected which will then allow Apple to invalidate your warranty (if still under warranty).
It wouldn't surprise me at all, given Apple's propensity for protecting intellectual property, that a "handshake code" exists between Apple's new batteries and authorized charging devices. You will be able to charge your battery with an unauthorized charger, but I wouldn't be surprised if code in the battery's firmware would indicate such has been connected.
Out of warranty, newer Mac...who cares! But, I don't think I would ever leave my new Mac on a third party charger in my camper unattended. And, I would charge the Mac on a small, inverted metal cookie sheet in case the battery goes into a melt down (my normal technique). It would be a huge bummer if one's Apple Mac exploded while charging catching your camper and truck on fire waaay out in the boonies!
My new truck has an inverter and 2x 110V AC outlets in the cab. We now only charge our Macs rolling down the highway with the truck's electrical system.
