Charging battery through 12V cigarette plug?
 

I assume the 12V cigarette plug is wired directly to the battery, there is no voltage stabilization. I know there is a fuse, but the charger maximum output (3A = ~40W) is way below the fuse rating.

I'm looking for a way to connect the charger easily ... how bad is it to connect it through the 12V outlet? (Ignoring the fact I'll have the male plug on the charger output)

During the winter time (this means mostly rainy ~0 to 5* C weather) I need to charge the battery quite often - but still don't want to take it out, so when there is a short weather window, I can go riding.

I would think that it would work to slow charge or trickle charge without an issue. Worst case it'll blow a fuse.

There is a simple way you buy furukawa plugs as they are in the motorcycle and make a splitter, and that's all without combinations and without bleaching the installation I did so.

I have a trickle charger that has the option of using an SAE connector. Each of my bike batteries wears an SAE pigtail so I can plug/unplug quickly as needed.

I don't see why reversing the flow like that on the socket wouldn't work. There are already gadgets for maintaining car batteries that work this way. Is the socket not switched with the ignition key, though? I would test that first.

You are right, the outlet is active only when ignition is on.
I guess I will attach the dedicated connector to the battery just for charging. I need to figure out how to protect the + wire ending, as my charger has crocodile clips only...