samluft

My unit doesn’t have a notch but the magnets will prevent it from connecting in reverse polarity. The magnetic will repell from each other if not properly aligned. Also all good aftermarket trickle charger have polarity protection built into their circuit so you don’t have to worry about damaging the car’s electronics or shorting out circuits.

Hella-Buggin'

It doesn't connect wrong because of the magnets. If you try and go upside down it pushes itself away. I know because I'm an idiot and tried LOL