Possible battery failure?

[Water Bear]

Quick update. Found a local Yamaha dealer that has my battery.

There was a death in the family and I won't be working on the bike until probably next weekend. Will update after new battery is installed and tests are run.

 

[Water Bear]

Still waiting on an opportunity to buy a new battery (I'm not even married, how do parents find the time for anything?).

I tried to run a test of the stator coil but don't know if I did it right, but it seems to check out.

I unplugged the RR and set my pocket tester to "200", which I think means "0-200 ohm range." It's the lowest setting my tester appears to have (could be mistaken). I shorted the tester and got a reading of 00.3, which I interpret as .3 ohms. Every which way I put the tester into the white wires at the RR plug, it read 00.6, or (I guess?) 0.6 ohms. If I left the tester probes in the socket long enough, it would drop to about 0.5 ohms...don't know why. Anyway 0.6 minus 0.3 is (drum roll please) 0.3 ohms, which is right inside the functioning range for the stator coil (0.22 - 0.34 ohms).

It's only 10 am local time and there are lots of houses / apartments nearby so I'm going to wait until lunch to fire 'er up and check the input voltage to the RR. At rest, I read 12.8ish volts on the red / black lines at the RR plug which I am guessing is battery voltage (?).

Also can someone explain this cryptic instruction in the service manual?

a. Set the engine tachometer to the ignition coil of cylinder #1.

I know what the ignition coil is (or at least I think I do), but what relation does that have to any tachometer?

Update 1: Just checked input voltage by hooking tester up to white wire leads. @ 5k rpm I read about 70. Tester set to AC Voltage, "200" setting (again, assuming this is 200 volts).

Update 2: RR was not hooked up when I did that test.

Update 3: Checked RR diodes, all were good. .54ish on all tests that were supposed to be non-zero, and nada on all the other connections. So now I think the battery is dead?

 

[FinalImpact]

Cryptic msg = tech is to ignore gauge instrument tach and connect their own to cylinder 1 to verify engine rpm?? Maybe.

No load AC stator testing doesn't tell you or us much. A new battery that is fully charged and then measure the white leads for output. Perhaps unplug your headlamps, measure, then plug them back in. The imposed load should be seen then.

The other thing to check is AC volts out of the red and black. It should be near zero as it is supposed to be DC.

The test above would be good test to compare RR output from current bad battery to new battery.

What is the highest voltage observed going into tha Li-ion and what is the lowest when cranking?

 

[Water Bear]

Cryptic msg = tech is to ignore gauge instrument tach and connect their own to cylinder 1 to verify engine rpm?? Maybe.

No load AC stator testing doesn't tell you or us much. A new battery that is fully charged and then measure the white leads for output. Perhaps unplug your headlamps, measure, then plug them back in. The imposed load should be seen then.

The other thing to check is AC volts out of the red and black. It should be near zero as it is supposed to be DC.

The test above would be good test to compare RR output from current bad battery to new battery.

What is the highest voltage observed going into tha Li-ion and what is the lowest when cranking?

Maybe a dumb question, how do I check the output of the white leads with the RR connected to the plug?

All I can think to do is get some really small clamping wires and hook the female ports on the plug to the male flag connectors at the RR.

 

[FinalImpact]

Basically back-probe it with your test leads. Any small diameter leads can slide into the back of the connector next to the wire.

Like this:

 

[Water Bear]

Basically back-probe it with your test leads. Any small diameter leads can slide into the back of the connector next to the wire.

Like this:

Thanks!

Hopefully I will find some time tomorrow to test the stator output voltage under load.

 

[Water Bear]

OK, ran some tests and got some interesting (bad) results. I did the tests once around lunch time and again at 2:30.

12:00 test:

RR input while engine idling: 10.6 V AC
RR input at 5k rpm: 11.2 V AC

Battery line voltage reads 25.6 V AC at idle.

2:30 tets:

RR input at idle: 10.1 V AC
RR input at 5k RPM: 10.8 V AC

Battery line voltage reads 26 V AC.

So tell me doc, how bad is it?

Edit: DC battery voltage was about 12.8 both times. DC bat voltage does rise as the engine is revved up to 5k.

Edit 2: Battery output line shows AC voltage even with the bike turned off, about 24.6 V AC. What...?

 

[FinalImpact]

Sounds like your meter is whacky! Post a picture of the front. Is it one you need to moves leads on for AC vs DC?

26vac would have killed the bike... safely measure your wall ac. Ground to Hot should get 120vac or so... be careful!

 

[Water Bear]

Pick of tester. It's in the setting I used to measure the AC voltage.

Edit 4: Just tested it on the wall and got a reading of ~119 V AC. Seems to be working.
Edit 5: I have made a terrible discovery. The battery itself reads ~20 V AC at the terminals. Either my multimeter is broken in a weird way or I have a super malfunctioning LI battery.

Battery AC voltage test
Battery DC voltage test

FI, in answer to your question, all indications are that I do not need to move leads for AC V.

Edit: I have been informed by an engineering buddy that pocket multimeters set to AC give false readings when hooked up to DC sources, that explains the odd readings.

 

[Water Bear]

I replaced the RR and it seems...improved. Output voltage from RR at idle is 13+ volts and the bike can idle without dying with headlights on.

I haven't driven it around the neighborhood yet or anything but fingers are crossed.

Thanks for all your help and suggestions [MENTION=24850]payneib[/MENTION] [MENTION=15974]FinalImpact[/MENTION] [MENTION=2579]Motogiro[/MENTION] [MENTION=6338]TownsendsFJR1300[/MENTION]

 

[FinalImpact]

Engine off pocket meter reads 20vac?
With engine on and it reads that it sounds like the RR has blown diodes...

But a new RR and all is well?

 

[Water Bear]

Engine off pocket meter reads 20vac?
With engine on and it reads that it sounds like the RR has blown diodes...

But a new RR and all is well?

Engine on, idling, output voltage from old RR was (IIRC) 11-12 volts, maybe even lower. New one is producing 13+ volts.

The pocket meter read ~20 V ac because it was detecting DC voltage in AC mode (with engine off, voltage at RR output should just be battery voltage). Probably what it does is read 2x DC voltage in AC mode.

 

[FinalImpact]

Just saying a proper meter doesnt report something that doesn't exist. If there is no AC possible or present because the engine is Off, it should read zero volts AC.

However with engine on and leaking diodes in the RR AC voltage may be present and it is present at very low levels like millivolts.... 10 to 20.... or 0.020volts AC.

So how is it working after replacement RR? Seem to be OK?

 

[Water Bear]

Just saying a proper meter doesnt report something that doesn't exist. If there is no AC possible or present because the engine is Off, it should read zero volts AC.

However with engine on and leaking diodes in the RR AC voltage may be present and it is present at very low levels like millivolts.... 10 to 20.... or 0.020volts AC.

So how is it working after replacement RR? Seem to be OK?

Haven't had a chance to test it thoroughly yet, unfortunately. You might be right - there might be something else wrong.

I actually tested the battery at the terminals, unhooked from the bike, and got AC voltage. This worried me so I asked an engineer friend of mine. Here is a copy of the conversation.

Me: Is it normal for Li Ion to have AC voltage?
Him: That's a false reading, so don't worry about it. Some of the fancy multimeters are sophisticated enough to recognize DC and report 0V AC, but they're too expensive for home use imo.

I followed the tests indicated in the service manual (except for testing the battery since it was dead) and the results indicated the RR was dead. Here's to hoping that was correct. (Fingers crossed).