Now that you mentioned Wal-Mart... I have one too somewhere. I bought it for my old car many years ago. It was supposed to be attached on the car's battery, with the short cord with the 110V connector. I remember 1.5Amp label on the case. I wonder if it is going to work for the bike's battery.Don't know whether or not a 15 minute run (total time running) will fully recharge the battery.
I would suppose that if you aren't having a problem, then it is ok. Does it still do well that way in the winter?
If I remember correctly, the MOM says if you leave it still for two months or so, charge it.
You don't need an expensive charger, just one that will trickle charge at 1.5 AMP or so (again, from memory).
I got mine from Wal-Mart. Long name, something like Shaumaker or similar. It works fine.
Make certain the AMP amount complies with your MOM.I found my old on-board type battery conditioner (SEARS product and it is labeled as battery conditioner). any suggestion on the connector type? I guess I could find any connector from radio shack or something, buy want to listen to other's experience.