Hi, maybe a bit late to answer to your battery problem but when i bought my dragstar 400 (second hand) ,i always had electrical problems ,would not charge well, difficult to start , ... i discovered that i had corrosion in the regulator connector,this regulator is really not installed at the best place ,right at the back of the front wheel,he recieve all the water he can get in bad weather; i replaced it with a new one in a new location, i installed it under a solo seat on springs so i have a lot of clearence, on top of the regulator i fixed a small 12v electric fan (the one used in electronic and computers) it goes on as soon i turn ignition key on, consume nothing ( 0.03amps) , perfect place , always dry , since ,no more problems ! So , Check well all your connections, especially the one on your voltage regulator, Cheers.