Charging issues


Hey folks

I had encountered with battery voltage drain issue.

Last weekend riding back to home, i just stopped for refueling, while cranking the engine i had observed that engine hard/struggle to start. Secondly instrumental cluster also reset without switching OFF the ignition. Engine was managed to start after 2~3 cranks. But found something fishy. After reaching home i had observed battery is drained out and everything of instrument cluster is blank.

  • I checked cranking after 4 hours engine started again but headlight illumination seems to be dim. Fuel pump also operates with noise.
  • Further disconnected battery, used Bosch C7 charger to recharge the battery. It took around 1 ½ hours to fully charge the battery.
  • Reinstalled the battery, started engine again. Checked charging voltage it was around 12.4~12.7V. It was clear battery was being charged by R&R unit.
  • I was tensed figuring what could be the problem. Physical inspection of R&R wiring while fitted in vehicle. No abnormalities have been observed.
  • Referred manual it says first check charging voltage it should be 13.5~15.5 V @ 5000RPM. In my vehicle it was less then the specification. Further check generator assy. Lift fuel tank, unplug generator coupler. Check resistance across 3 lead wires it should be 0.2~0.7 ohm.
  • In my bike it was 0.7 ohm. Across lead wire continuity has been observed but not through lead wires and ground.
  • Further noticing the generator coupler out of 3 terminal 2 terminals was loose. Connector has been found to be burnt from inside resulting loose connection. To verify generator assy. is working fine direct connection has been done and engine is started at idle charging voltage was 13.5 V while @5000 rpm it was 14.8 V (max)
  • OEM does not provide same connector as separate part, hence went to automobile market along with sample : surprisingly same connector is used in various other automobiles : car air conditioner, fog lamps and headlight unit.
  • Fitting the new connector, checked terminal fitting OK, started the engine charging voltage is 13.2V (High beam ON), @5000rpm : 13.9V
  • Something that i haven’t found Ok was when high beam, hazard lamp is turned ON charging voltage dropped to 13.1 V. Further in same condition when both cooling fan where switched ON charging voltage further dropped to 12.5V.
  • After fitment of new connector i went on ride last 2 days back and found Horn sounds weaker, after switching ON high beam it became more weaker. Again after cranking engine instrument cluster blank and battery voltage dropped.
Figuring out what would be the possible cause of drop of charging voltage : Generator assy., regulator & rectifier assy.





Donating Member
My 2009 Killed my battery and I almost didn’t make it home. I’m my case it was a bad rectifier that would act up when it got hot and replacing it with an upgraded Rick’s one fixed my problem. Not saying that this is your problem, but we have even seen members report rectifiers catching on fire and mine was even the “upgraded” oem unit that Suzuki replaced under their recall.