charging system problem

ok, here is what i got. just remounted and reconnected stator. started bike. initial voltage was 11.9 to 12.05.
let it warm up. gradual increase to 4k. voltage went up initially to 12.8 then began a slow rise to 14.2 after about 10 minutes. went back down to idle. and after about 2-3 minutes voltage stabilized at 12.2.

still have not had the battery load tested. but it was on the charger overnight, and most of today.

so now im totally confused, sometimes it doesn't charge at all. and sometimes it does better.

jim

can you try the same test with the headlight fuse pulled?

It should go to 14v sooner than 10 minutes at 4000 RPM. If you have a Dyna S ignition installed, that could be using the extra power you need to charge the battery.

Hello to all, I am having the same problem on a 73 z1 with a 76 903cc motor. I would like to hear more about dyna coil mods. I was never having problems with my charging system untill i installed dyna coils. The bike is quite old and the parts have been good for years. I want to replace every part but that can get very expensive. Do some parts fail more often than others, i have the rectifier that is separate than the voltage regulator ,and have only one fuse for the whole electrical system. I couldnt get a reading on my stator or the extra one i have, how do i test a spare stator off the bike? jccwall i hope you figure it out with the help of this knowledgeable forum, my symptoms are scary close to yours, but im not real experienced on the electrical end of it YET. Thanks to all

honestly, i was thinking that it was due to the coil mod that was made for the extra power being pulled. but will look to see if it has a fuse for the head lamp. if not i can disconnect it and retest.


jim

I have already suggest once that you should eliminate the battery itself as the source of the problem. The suggestion was to use a hydrometer to test for sulfated cells. On EVERY charging system troubleshooting diagram or flow chart, battery testing is the first step. Good luck with your problem.

ok, wg. you were correct. i just bought a hydrometer and checked battery. it failed. only 50% in all cells.
will get a new battery and hope this problem is resolved.
The question is, though, what might cause a brand new battery to go bad so quickly?

thanks again.
jim

Post edited by: jccwall, at: 2007/11/30 16:54

Got another battery. Filled it with acid, let it sit 30 minutes as per instructions, and placed it on a .400ma trickle charge. Instructions called for either 1 or 1.5 amp charge. My choices were 2 amp, or the trickle charger. I decide to take the conservative route.

I seem to remember reading something about potential problems from improperly charging batteries initially. Am I OK?

At least you caught one of the issues before buying new hard parts for your bike. I did some looking awhile back and couldn't find much solid info on how to charge a motorcycle battery. I have always used the low amp trickle function on my charger (mine is 1A) and charged for at least 12 hours. I seem to recall that there is a higher possibility of sulfation of cells if you charge at too high or too fast a rate.

Since your stator seemed fine, I suggest once you get the battery charged to install, clean all associated connectors with ELECTRIC CONTACT SPRAY CLEANER (auto parts store) and dab contacts with dielectric grease and then retest the reg/rec by putting multimeter contacts on your battery terminals and checking at idle and 3500rpm... should see a tad over 12 VDC at idle and about 14.5 VDC at 3500 rpm.

How did you charge your old battery?

if i recall correctly. dont think i actually charged it before putting it in. filled it up let it sit for about 30 minutes then installed.