I generally keep my cars/motorcycles on trickle chargers when not being driven.
Shouldn't have to actually install a trickle charger, for the M3W, the accessory plug is directly wired. Just get an adapter to fit the socket and plug in easily. No extra wiring or sockets.
Any idea where I get that? I'm not sure what the accessory plug looks like, I'll have to take a look tonight. Or do you mean the 12V socket in the cockpit?