You should be fine, commercial vehicles are exactly the same as aircraft voltage wise.

I had a similar problem. I blew up my iPad charger and a miniUSB charger for my bluetooth GPS not realising that my Cessna has a 28V supply. I believe the Skydemon GPS unit has a miniUSB socket. I bought one of these from Amazon. It arrived in a couple of days and I haven't blown it up yet. I'm hoping the device can handle an extra 4V. Commercial vehicles I believe, use 24V, so these give you a better chance than a 12V charger if your aircraft is pumping out 28V

check this website

http://www.sportys.com/PilotShop/product/16429

and here is another one

http://www.amazon.co.uk/Dual-Cigarette-Powered-Charger-iPhone/dp/B00EJG18W0

Bouwair

Hey folks,

Ive got a Sky Demon GPS unit and I want to use the cigarette charger that was supplied with the kit in a C152. Now the C152 has a 28v DC output but I believe the GPS unit requires a 12v supply. Are there any convertors that I can safely use to do this?

Ive had a search around online but im just getting lost, im not that great with electronics so would rather get it right rather than fry my clubs aircraft ;-)

Thanks

Ewan