charging battery

[mike58]

Is their any reason not to charge the battery while still in the bike and hooked up? 2007 nomad 1600 if that makes a difference.
I have a tender on it and i noticed the light stayed red for a couple of days so i tried starting it and it was dead. Hum that's a new battery installed in July. So took the seats of and everything looks fine and when i put the tender back on it seamed like the red light was a lot brighter than before, that was 2 days ago. Yesterday the light was green and it seamed a little odd that a trickle charge will bring it back in one day. Today i tried starting it and definitely has more juice than the other day but not enough to start it so now I'm impatient and thinking of just putting a regular charger on it used for automobiles.