charging voltage

smokegetsinyoureyes · Aug 10, 2012

This all started when my max would'nt start when warm a couple of times, I took the battery out and charged it overnight, disconected the charger next morn and left the battery untill I returned from work about 8-9hrs later. The battery voltage then was 12.4 (thought is should have been higher? I have the shunt type r/r, it and the stator checked out ok with the meter, I soldered a new eye onto the earth cable which bolts onto the r/r mount sa the previous owner had almost cut it fittin a new r/r. cleand all the terminals including engine earth and battery, the only thing that has'nt been done is running the live from the r/r to the battery and doing away with the plug to. the stator. With the fuse out for the lights the following voltages were obtained: 1000rpm 14.2v. 1500rpm 14v. 3000rpm 13.75v.With the lighting fuse in: 1000rpm 12.9v. 1500rpm.13.9v. 3000rpm.13.3v. Why does the voltage drop as rpm rises. I intend to do the mods on the wiring from live r/r to battery and stator plug and intend to break into the wiring at the 15A fuse with a switch for the lighting. Any help would be great.

Buster Hymen · Aug 10, 2012

Your charging voltage is good but that doesn't mean your battery is accepting the charge. How old is your battery?

sdt354 · Aug 10, 2012

Buster Hymen said:
Your charging voltage is good but that doesn't mean your battery is accepting the charge. How old is your battery?

+1, 12.4 volts is a bit low for a fully charged batt.

zexus · Aug 10, 2012

I had a very similar problem only a week ago. I to checked my stator and r/r, and both are okay. I did all the mods to the wiring to increase voltage and things improved. It turned out that the main problem was the simplest culprit...the battery. My PC680 was on its last legs, so I replaced it with something a little different...Ballistic Evo2 12-cell. Regardless, probably a good idea to have your battery checked. Though I am no expert, I don't think your battery reading should be 12.4 after sitting for 8 hrs from a full charge.

95spfldmax · Aug 10, 2012

smokegetsinyoureyes said:
This all started when my max would'nt start when warm a couple of times, I took the battery out and charged it overnight, disconected the charger next morn and left the battery untill I returned from work about 8-9hrs later. The battery voltage then was 12.4 (thought is should have been higher? I have the shunt type r/r, it and the stator checked out ok with the meter, I soldered a new eye onto the earth cable which bolts onto the r/r mount sa the previous owner had almost cut it fittin a new r/r. cleand all the terminals including engine earth and battery, the only thing that has'nt been done is running the live from the r/r to the battery and doing away with the plug to. the stator. With the fuse out for the lights the following voltages were obtained: 1000rpm 14.2v. 1500rpm 14v. 3000rpm 13.75v.With the lighting fuse in: 1000rpm 12.9v. 1500rpm.13.9v. 3000rpm.13.3v. Why does the voltage drop as rpm rises. I intend to do the mods on the wiring from live r/r to battery and stator plug and intend to break into the wiring at the 15A fuse with a switch for the lighting. Any help would be great.

That's working correctly I say. It charges most just off idle and fades further up the rpm's......Doesn't over charge the battery would be my guess....It says in the book "14-15v @ 5000RPM".....but (with lights on) s/b about 14.5 or so at 2k-2.5k and maybe 13ish up higher.........both my bikes have done that anyways....... Is this simular with what other people experience?