I found a new product available where I work.
It's just like a battery tender, but a little bigger 4"X5"x1-3/4"
Fully auto, 1.5 amps 12volt only. Will keep your battery topped up with no chance of dammage to the battery. You can mount it if you want to. It's $54.08 available at Acklands Grainger. Part number SOL 1002. Many branches through out B.C., plus if you have a buddy who works there you might be able to pick it up for a bit less. Not trying to pimp my place of work, just passing on a good product for a good price to fellow riders.