Flat battery - why?

[Matchless]

psyguy,
It looks like you are charging, but drawing more amps than your stator can provide. It could likely be a schenario of one phase not putting out any juice. The most likely culprit would be the stator and I suggest that you disconnect it and test for 80V AC (at 5000 RPM) between the three legs, they should all be similar.

If all is OK there I would give the R/R another look.
Keep well.

[posplayr]

psyguy,
It looks like you are charging, but drawing more amps than your stator can provide. It could likely be a schenario of one phase not putting out any juice. The most likely culprit would be the stator and I suggest that you disconnect it and test for 80V AC (at 5000 RPM) between the three legs, they should all be similar.

If all is OK there I would give the R/R another look.
Keep well.

I agree with Matchless that your are not getting enough juice out of the stator. The R/R is regulating, but as you continue to run the voltage continues to drop below any level that is capable of charging the battery.

When you switch the light on and the voltage drops to 13.7V that is a big drop in and of itself but there is still enough to charge a battery (above about 12.8V or so.) However if that resistance were to increase with temperature, it would be sufficient to quell the output of the charging system.

It is clear that the charging sysyetm is not working Refer to Phase A Step 2 of the revised stator pages. You probably will pass this when cold but progressively fail as you run due to some heating.

http://www.thegsresources.com/_forum/showthread.php?t=143019

http://www.posplayr.100megsfree3.com..._Phase%20A.pdf


I suggested before directly measuring the voltage difference between R/R (+) and Battery (+) at 5000 RPM as you ride. If that voltage is more than 0.25V-0.5V then you have connection problems. Run a direct fused wire between R/R (+) and Battery (+) to confirm that you can get that voltage low.

This will save you from a stator swap and additional running around.

[reddirtrider]

Some of these bikes have the 3rd phase routed through the front controls and it's only engaged when the headlight is on. Check those connections to make sure they aren't goobered up.

[posplayr]

+1 on the overdraw.

Tell us about your headlight. What bulb? Did you modify or "upgrade" bulb or light?

Could be high resistance switch, harness, connectors to headlight.

Keep following the other advice above. I'm trying to think of anything not mentioned.

- JC

I think what is being discussed is an inability to deliver the required load, not so much an overload. The stator cannot put out rated load due to either:

A.) temperature sensitive breakdown in the stator windings
or
B.) temperature sensitive poor connections (some where)

The suggested measurements will provide the answer.

[posplayr]

If the only thing that was going on here was that the headlamps was 100 watt instead of 55 wats and the battery voltage drops to 13.8V when the lights are on then there is another problem. There is nothing to suggest to me that that type of load would be the problem.

13.8V is sufficient to charge a battery as it is more than a volt above the battery internal voltage (e.g. 12.8v) Something else is causing a drop in battery voltage as that battery is charging at 13.8V.

Your presumption is that the battery charge is decaying from 13.8vv down to 12.2v due to cumulative loss of charge due to excess draw. That can not be the explaination for the problem in that anything above 12.8v represents charge flowing to the battery. If charge is flowing to the battery the voltage cant go down. There is something else going on as I described.

[/LIST]If he's running, say, a 100w headlight instead of a 55w (or whatever the limit), the above could happen. Overdraw, overheat wires, further overdraw.

Headlight off=okay
Headlight on=drain
Headlight back off= okay again

By all means test the other stuff, but it makes sense to check the circuit that is possibly triggering the problem, too.

- JC

[Matchless]

My experience has been, considering R/R, wiring/connections, stock lights all being standard and working, it usually is the stator being partially short circuit on the windings and may show some visual burning on one or more phases, usually only the outer layers of the windings. Getting about 25V Ac instead of the 80V at 5000 RPM is an indication. Heat may or not play a role here and the short circuit may not be present with the stator cold and come on when the wire expands.
The resistance test of the windings is too inaccurate to use and an "Low Insulation" 500v/1000V tester may show it up, but only if it shorts to ground. Partial winding short circuit is hard to measure when you always have 6 x 2 poles in series and the total resistance is less than 1 ohm.
I suggest checking the stator output when cold and hot.

Just for info: Rewinding with heavier wire has its limitations as the amount of wire layers and turns you can get on each pole are usually less. The actual limitation is the distance that the poles are apart at the bottom and the length of these. It is possible to get 80V AC with heavier wire, but you need to wind it absolutely perfect with each winding properly squared against the previous, so that no space is wasted. This can only be done with some skill and experience. The beauty of such a rewind is that you start charging significantly at lower RPM's and show a positive charge even while driving very slowly in traffic.
Aftermarket stators may be wound with less copper or using thinner wire and then covered with a coloured resin making it difficult to see and are not necessary bullet proof. The resin and the type of enamel used on the copper wire is also part of the longevity of the stator.

[posplayr]

Matchless,
I agree with your assessment but would only add, that since we appear to be dealing with a temperature sensitivity we need to conduct the stator pages voltage measurements with that in mind.

It is not conclusive that the stator is the issue and it would be unfortunate to swap it out when in-fact it is a temperature sensitive connection else where that is causing the R/R to regulate improperly.

If Psyguy can verify all the steps in Phase A of the revised stator pages, and have good connections but low output when hot then it is much more likely to be a bad insulations in the stator.
Jim

My experience has been, considering R/R, wiring/connections, stock lights all being standard and working, it usually is the stator being partially short circuit on the windings and may show some visual burning on one or more phases, usually only the outer layers of the windings. Getting about 25V Ac instead of the 80V at 5000 RPM is an indication. Heat may or not play a role here and the short circuit may not be present with the stator cold and come on when the wire expands.
The resistance test of the windings is too inaccurate to use and an "Low Insulation" 500v/1000V tester may show it up, but only if it shorts to ground. Partial winding short circuit is hard to measure when you always have 6 x 2 poles in series and the total resistance is less than 1 ohm.
I suggest checking the stator output when cold and hot.

Just for info: Rewinding with heavier wire has its limitations as the amount of wire layers and turns you can get on each pole are usually less. The actual limitation is the distance that the poles are apart at the bottom and the length of these. It is possible to get 80V AC with heavier wire, but you need to wind it absolutely perfect with each winding properly squared against the previous, so that no space is wasted. This can only be done with some skill and experience. The beauty of such a rewind is that you start charging significantly at lower RPM's and show a positive charge even while driving very slowly in traffic.
Aftermarket stators may be wound with less copper or using thinner wire and then covered with a coloured resin making it difficult to see and are not necessary bullet proof. The resin and the type of enamel used on the copper wire is also part of the longevity of the stator.

[psyguy]

thanks guys.

• the headlight is standard 55w, no mods.
• the rr is honda model with the sense wire and the rr +/- are connected directly to the battery

i'll check the stator output when cold and hot.

however, my bet is on the following:

Some of these bikes have the 3rd phase routed through the front controls and it's only engaged when the headlight is on. Check those connections to make sure they aren't goobered up.

[psyguy]

ok, done some more testing.

warmed up the engine and tested the stator:

• voltage on all three legs reads upwards of 80V.
• however, when i connected one leg through the headlight switch, on the return wire that goes to the rr i get no signal (no voltage)

so, would you recommend to connect all three phases directly to the rr (that has a sense wire) or to try trace the problem in the stator-headlight circuit?

if you could tell me the pros and cons of both options that'd be great as i'm keen to learn more about the electrics

[chef1366]

Run all three stator wires straight to the R/R. Keep the headlight on. (safer anyways) Problem solved.

[reddirtrider]

Run all three stator wires straight to the R/R. Keep the headlight on. (safer anyways) Problem solved.

That's probably the best bet.

Something that is overlooked on this mod, however, is that the R/R will need to shunt more current to ground and may get a little hotter.

[psyguy]

Something that is overlooked on this mod, however, is that the R/R will need to shunt more current to ground and may get a little hotter.

you mean, in case i run with the headlight off?

[Matchless]

psyguy,
If you already have a better R/R fitted such as the Honda units, usually meaning a higher capacity one than the original OEM R/R, you should not have any problems riding with lights on or off.
That approach actually reduced the charging current by a third with the lights off and so did not overtax a slightly low rated OEM R/R.

I think when Suzuki introduced the third phase to be switched on when the headlights are on, they actually used a lower capacity R/R and that may be part of the reason why so many of those gave problems and the Honda units were/are much more bullet proof although they are made by the same manufacturer. Any 25 A or even better 35 A rated R/R will be quite safe with the lights off at times as well, but 20 A and smaller becomes a bit dicey. A 16 A will get quite hot with lights off, but may be OK with lights on and an old battery, but is more likely to fail over time. Some people have even fitted fans to the R/R's. reddirtrider is correct if you still have the old OEM fitted or a low current rated one.

If you do not know the capacity, manually checking them for heat after a ride with the lights off and battery fully charged will guide you. If it burns your fingers it needs to be uprated, if just warm to the touch you should be OK.
If you ever replace it, get the highest current rated R/R, thus from the larger bikes.

[Steve]

Let the headlight draw off the battery point if it needs it, ...

Actually the headlight ALWAYS draws off "the battery point".

On the older bikes that actually had a working headlight switch, there were two sets of contacts. One set controlled power from the battery (actually the fuse box) to the headlight, the other was in the third leg of the stator. The stator NEVER powered the headlight directly. If it did, you would need special bulbs that would work on input voltages that ranged from about 20 to 90, with no problems.

Interestingly enough, I found on a previous bike that the third leg of the stator put out just a bit more power than the headlight consumed. I had a voltmeter connected to the battery and found that the voltage was higher (battery charging better) when the headlight (and the third stator leg) was ON.

Overall, you are better off by connecting your stator directly to your r/r, whether you use new bullet connectors, new spade connectors or solder and heat-shrink. If your bike also has a working headlight switch, just keep in mind that your headlight should also be ON most of the time to minimize how much the r/r has to work, although it is nice to be able to turn the light off if you are in very slow traffic. This will help keep the battery charged at lower engine speeds. The best idea is to mount a voltmeter of some sort to the bike so you can keep an eye on the system.

.

[flyingace]

In looking at the diagrams for bikes with light switches, I see the wire routed from the stator goes thru a seperate switch in the headlight switch housing, not thru the light itself. That seperate switch simply routes the current back to the R/R only if the headlight is on.

I think it is a common misconception that since the stator wire goes to the headlight switch, that the current from it goes thru the headlight. Steve is right, that wouldn't work.
The whole point of the arrangement is to insure you don't overcharge the battery while running without the headlight.

In this case, the opposite is happening. I would have to wonder if the wire from the headlight switch to the R/R is carrying current back to the R/R. In other words, the headlight switch is working and the headlight is on, but no voltage is being delivered to the R/R from the stator leg going thru the headlight switch.

It makes a degree of sense since the headlight would be on, but only two legs of the stator would be delivering voltage. This appears to be the W/R wire into the R/R.

If you've already tested all the leads going into the R/R, then disregard this diatribe. In any event, I agree with just hooking up the wire routed thru the headlight directly to the R/R. But I'm glad I finally got this figured out.