Battery issues

[9mmPreacher]

So, I took my battery back to the dealer since I bought it used and it doesn't start without a jump. I also bought a trickle charger and thought that would ease my woes. Nope, it appears that the battery won't hold a charge at all. The dealer appears to think the battery is okay, I don't think they actually tested it properly. When I picked it up from the dealer they said it was good. So I put it on the bike and yes it started I took it around the block and let it idle for a little bit. I shut it down and then tried to start it back up again and it wouldn't turn over. It was very weak and didn't start.

So, I am almost positive that my battery is weak and won't hold a charge. Does this sound right? I know there is not an alternator, but is there something similar to this on the bike? I could definitely use some help.

Thanks guys,
Drew