Having recently got a travel mobility scooter for the Mrs I'm still pondering how to charge the batteries on longer trips and came across one of those inverters you can plug into your cigarette lighter which I always thought were crap but its listed on a large mobility scooter site and wondering if that gives the idea some credence or not?
www.careco.co.uk
Anyone got any thoughts?

In-Car Inverter
The In-Car Inverter Mobility Scooter Accessory connects to the cigarette lighter in your car, so you can charge your scooter battery on the go.

Anyone got any thoughts?