Charging the Harley battery via the cigarette lighter connection?

Moin Moin, does anyone have experience with power sockets? I would like to put such a can on the frame of my Harley to charge the motorcycle battery via the connection of the cigarette lighter. Have pictures charged – the can is connected directly to the battery (power cable with eyelets). Unfortunately, find no clear information. Some claim that the battery is only partially charged, others say it works…. Can someone recommend me a proper can + matching charger hlen (if it works)? Currently I have to dismantle the seat and release the tank to get to the battery (custom frame / parts). About short info I would be happy to have a nice weekend. Greeting Steffen