Battery not charging when lights are on.
 

As usual, I'm a supplicant to the greater combined experience of the forum, it's my 3AJ XT600z.

I've been having problems with my battery recently and have bought a new one. I now find that the charging circuit is not working well enough while the lights are on. The garage checked the voltage and found 13.xx volts when the engine runs and the lights are off and 12.xx when the lights are on.

Will I have to change the rotor and/or the stator or is it repairable?

Alex

First things first
 

The XT's have a rectifier / voltage regulator that checks whether it 'sees' an adequate battery. So, if the voltage from the battery is too low, it will not provide charging current. So, the cause of your problem might be a worn battery.
On a more conceptual level, there is four components that might be faulty:
- Alternator (the stator part with the coils) - measure resistances and compare with those from the book. If they are way off, it might be faulty.
- Wiring - check all connections and cables, clean, tight etc? o not underestimate the number of manhours and the amount of $$ spent on other components while there is just a broken wire.
- Rectifier / regulator - no other way of checking it (known to man) then to swap it for another and check whether there is improvement.
- Battery - see above.

Auke

Are you running any extra lights or just the stock headlight/taillight?

Ron

You should also check you are using the right wattage bulbs for your XT6003AJ
some models Austria, Finland, Holland, England use 2 12volt 35/35Watt bulbs while others use higher wattage bulbs.
I think some are also wired so only one light works at a time while others can have both lights on.
Good luck

All good stuff.
 

This is all good stuff, I'll take a look at the rating on the lights, though there are no additional lights on the thing. I'm not 100 percent convinced that the new battery is good, if it wasn't perhaps it would have too great a voltage drop with the lights on and the rectifier would stop it charging? I'll report back when I have more info.

Hi if you need to get a new battery it is worth spending a bit more money and getting a Yuasa battery cost about £40, should be able to get one in Hallfords.

Also check your voltage regulator is earthed.

If you need a new stator you can get one from Eletrex or they can rewind your one.

On a lot of bikes this is a sign that the regulator/rectifier unit is about to die. Unfortuantely the only way to check this is to swap the unit - it may be worth trying to locate a second-hand one and swapping it over.

Check your headlight bulb wattages
 

If both headlights are wired to come on you should be using 35/35W bulbs. The charging circuit cannot charge the battery if you use 55/55W (or higher) bulbs. If only one light comes on (e.g. German models) you can use 55W.

Sorted!
 

I finally got around to checking the power of the bulbs and they are both 55/55W lamps, so that'll be the problem. Thanks once again everyone who replied, you keep my bike on the road.

P.S. It was MOT'd just before Christmas, so I now I have my first motorbike on the road and I built it myself! Couldn't have done it without the forum.

http://www.flickr.com/photos/4981785...7594237835258/