My 99 400ex will not keep the battery charged. I replaced the battery at the end of last season. The bike just doesn't seem to be putting enough current into the battery to keep it charged. I went on a weekend camping / riding trip. Yes I started and stopped more than a normal ride, but by the end of the 1st day the battery was dead, and I had to bump start it the rest of the weekend. Upon returning home I put the charger on it to bring the battery back to full. During the current riding season, I've had to put the charger on the battery a few times to help maintain a full charge.

The charging unit just doesn't seem to putting out enough juice to keep the battery charged.

I believe the alternator is putting out the proper juice as the lights are strong, are not effected by the engine RPM range.

Could the regulator be the bad link in my situation?

 

If the stator is putting out juice, then the rectifier is bad.

 

Thanks Bounce400ex, that's what I thought... A new (used) rectifier has been ordered.

 

I've got the same exact problem. Can you offer me a little insight into what exactly the rectifier is? Is it that round thing behind the battery that the positive battery lead runs into?

Thanks a lot, as this is driving me nuts

 

The rectifier is the alternator on the bike. Here is a link to one on E-Bay

http://cgi.ebay.com/ebaymotors...QrdZ1QQsspagenameZWDVW

 

The stator is inside the left cover. It produces 3 phase ac power. 2 of those phases go to the rectifier to become dc current and charge the battery. So the rectifier changes the ac current to dc current and once the battery is at full charge the extra juice is released as heat through the heatsink.