My 05 KLR has always overcharged its batteries.
After a 1000km (600mi) trip, with the original the water level would go from slightly above the "full" line to just below the top of the plates. My nearest Kawi dealer ripped me off the only time I went there, so I haven't been back and never bothered going thru the hassle of making a warranty claim.
I had to buy a battery on a Saturday night before a trip that was planned for the following day, and found a sealed battery at K-Mart that was the right one for the KLR. Of course, I haven't been able to top up the water level in that, and now it's dead too.
I measured the voltage of the battery with the engine running: 15.5V. This is WAY too high.
I looked at the spec. in the KLR600 Service Manual (Base section p 14-7), and it says it should run at 15V.
(See pic @
http://i293.photobucket.com/albums/mm57 ... gVolts.gif ).
This is WAY too high !!!
If you type "automotive battery charging" into your favourite search engine, you will soon find statements like
"The charging system provides essentially a fixed voltage of typically 13.8 to 14.4V, unless the alternator is at its current-limit" (
http://en.wikipedia.org/wiki/Car_battery).
One possible reason for a high charging voltage is a voltage drop between the battery positive terminal and the voltage sensing wire that goes into the regulator. In the KLR's case, this is the brown wire (BR):
( See Charging Circuit pic (manual p14-6) at
http://i293.photobucket.com/albums/mm57 ... gCct01.gif )
This wire is disconnected when the ignition is switched off, so that it will not drain the battery when the bike is not in use. However, if there is any voltage drop between the battery "+" and the regulator, eg due to resitance in the wiring and dirty contacts in the ignition switch, the regulator will see a lower voltage than is actually at the battery, and it will increase the charging voltage to compensate. If this is happening, you can cut the brown wire and wire in a relay that connects the positive lead of the battery directly to the sensor input of the regulator when the ignition switch end of the brown wire is activated.
I measured the voltage drop on the KLR, and to my surprise found it was less thatn 0.1V, so this is not the source of my overcharging problem.
Where can I get a regulator that charges at around 14.0V, or how can I modify the existing one to do so?
[I searched the DSN_KLR650 archive for "overcharging" and found just 2 references to similar problems
"charging system, wiring & Electrex results, theory & reality" -- Jim Hyman, 2 Apr 2001, and
"Battery or rectifier?" -- dcorym, 16 Jun 2003
... but no followup posts.
]
- Rick -