I use have the wired connection with the plug on the end that came with my optimate, this has a splash cover over then end, then just take the seat off and connect when needed.
Though I find I only need it over winter, if you need it in the summer then you need a new battery or to get your arse out on the bike more often
Though watch the fuse holder, I found it had come a little unscrewed and when starting the bike it could "trip" the whole system with a click and go dead, turn it off wait a few then on again and all would be well but worried the hell out of me for a while (also lost the top speed in the ECU... grrrr )