trickle

Hello Gentlemen, My Vmax has had half of of a trickle charger since I bought it 6 months ago. Now that winter is almost upon us, I would love to get the other half. There are no brand markings anywhere on it and it is already hooked to the battery. If anybody can recognize the plug below...

what do you guys think about a solar powered trickle charger? I park the bike under our condo unit with no access to an outlet. here's one i found this one has some pretty good reviews...