Still have some charging challenges.

[Guest]

Now after crowing that I had sorted my charging issues with a good cleaning of some contacts and replacement of those from the stator I'm back to similar issues.

When first started the bike will not charge at idle but does start as soon as revs rise. From then on its always charging. When dropping to idle at a a stop or light it seems to push out 13.+ volts climbing into the high 14s when running up to 5000. Turning on signals and high beam drops it a skosh but nothing drastic. If I turn off for more than 5 minutes it starts up the same way i.e. no charge at idle but charging as soon as it moves.

As the stator legs still show good voltage touching 90V at 5000 rpm, I am now convinced the R/R is wonky.Question is, is it wonky enough to worry about? As long as I'm not boiling off battery fluid I should be ok no?

I'll hunt down another R/R for backup but I may not change it out immediately and put it on the list of winter work.....unless my logic is faulty.

Comments folks?

[bonanzadave]

Mine wont charge until just above 1500RPM. Thats typical.

[duaneage]

Sounds OK , idle speeds reduce output of the stator a lot. Most motorcycles of this era have similar. A 10 minute rude should restore the battery after starting the bike..

[doctorgonzo]

Agree with consnsus. I only show about 13, sometimes as low as 12.5 at idle. It them peaks at about 14 at 4000 RPM. That may improve a little as the last of my old wiring was replaced in current rebuild. rewired signals, headlamp, etc...

[duaneage]

LED tail lights and turn signals improve the idle voltage a bit, in the end it doesn't really matter since as soon as you take off it is fine. If I'm in traffic for more than a few minutes I turn the bike off, no sense cooking it in place.

[MacGyver]

Sounds normal to me also. On my KLR I put in LED tail/stop lights, LED license plate light, and LED bulbs in the instrument cluster to save me about 30-40 watts at idle. This was more to accommodate my grip heaters and any other electronic add on gear I may adventure tour with. I focused on lights that were on all the time and didn't bother with the turn signals, besides, I like big ugly bright signals that can be seen for miles and I only wanted to spend $30 on one brighter than stock LED for the brake light.

As others have stated, while you are not 'charging' at idle, you are not really 'discharging' that much either.

[spyug]

Thanks for all the feedback.

I don't think I was explaining this correctly. Prior to me doing cleanup on the wiring and connectors the bike had always charged to the high 14s right off the bat......from idle right up to about 3500 rpm.

I was told ( and I kind of knew already) that proper charging should start at around 2500 going up to a peak of 14+ around 5000 rpm.

At first, after the cleanup, it seemed things were right as it didn't start charging until the revs hit about 2500 and went up nicely to the high 14s around 5000 where it started to drop off a bit.

Once I started riding it was still fine but as soon as I came to a stop or otherwise allowed the bike to come to idle it was still charging a good 13+v even at as little as 1200 rpm. According to what I read and was told this is not correct.

I'm not overly concerned about this but I'd like to understand what may be going on. Something just doesn't seem quite right.

My on board voltage meter is a cheap analog unit just to give me a headsup when out and about. It is definitely not accurate so I might actually be imagining things. I think I might temporarily wire in my multimeter and take it for a ride to see what I get.

I'll let you know what I find.

Cheers,
Spyug

[Road_Clam]

The spec for the charging system is 14 to 15.5V at 5000 rpm's. Anything under 12.5V is "not" charging. Not getting anything at idle is normal. That's why you don't ever want to get stuck in traffic with a low battery

[twiggy2cents]

i have a stock one for a 85gs550 if it fits yours you can have it, i dunno if it works or not.

also my old r/r wouldnt charge and would actually dim the lights then when it warmed up a little and i revved it you would see the light get bright instantly

[duaneage]

Keep in mind a few things.

Once the battery is topped off, the operating voltage goes down a bit. The RR powers the bike, it's not just there to charge batteries with. That's what a trickle charger does exclusively. Once the battery is charged, it becomes less of a load. After all, it's not a resistance but more like a capacitor. RRs and stators power all the electrics, not just the Yuasa under the seat.

Rather than say the bike is charging, a more correct term is to say the bike is operating at normal voltage levels. The battery is back up to normal levels pretty darn quick, as long as the cells are in good shape and the fluid is OK without being contaminated.

When your looking at 12.4 at all engine speeds with a gradual drop to 11 then tell Houston you have a problem.

I agree about being in traffic with a weak battery, On a hot day especially, that can get scary since if you stop the engine it might not start again. My bike has a lights off switch, That is something to consider adding right after the fuse box to conserve power in a tight situation. Also handy for troubleshooting or starting a bike without straining the battery.

[tas850g]

i recently checked my VAC and at idle i was getting around 12.8 vac from the 3 legs. I was thinking OMG but when i brought it up to 4k it ramped up nicely to 61 vac. That's what it was when i got it used and it is still operating at normal voltage levels. Nice to read that is normal to have low vac at idle.