Topic: 76 CB550K No Charging and Draining Battery

[alecholmez]

Hey All,

I've been trying to diagnose a recent charging system failure and I'm a pretty big noob when it comes to wiring. So I have the stock harness, and recently did a wire tuck in a battery box. I noticed the oil light had a really faint glow that definitely was not light bleed from another bulb. Besides that onto some numbers and helpful things about the bike:

- New LED small guages up front
- Stock headlight
- New Rick's regulator/rectifier (maybe 1,700 miles on it)
- New Rick's starter solenoid (OEM one failed so I replaced it)
- New shorai lithium-ion small battery (the small one from cognitomoto I believe it's the LFX14A2)
- LED tailight/license plate light

The bike had been charging and running great for a while but all of a sudden I noticed a rough idle and weak spark, along with flickering lights and super low electrical output (lower than usual) at idle. I let the battery charge overnight, let rest for a few hours and measured output at 13.2V without anything on.

Turned the key and started the bike and the voltage was pretty much a constant 13V up until around 4K which it started to drop to around 12.4 and kept dropping as I drew more current on the ignition circuit when revving higher and higher. I have no clue what's up and have verified the regulator/rectifier, the yellow wires from the stator were all at about 0.39ohms, but the odd thing was when I was verifying the black and white terminals after disconnecting the reg/rect, I saw huge resistence numbers, 8ohms when I had the headlight switch on and 17ohms when it was off, apparently that's supposed to be 0ohms? Any ideas what could be causing this issue?

[bryanj]

Three most common problems in order
1 bad ground somewhere
2 bad connectors to field coil
3 bad reg/rec

Very Very rarely do you get a bad field or stator coil and then usualy from physical damage.

[Bodi]

Resistance readings on an electronic regulator are not very meaningful, because it uses semiconductor switches - with the original mechanical regulator you are measuring a relay contact and the "part power" resistor - they can have their resistance measured.
Confirm the ground (battery negative to frame) is good - zero Ohms or very close - and that the connection directly from battery to regulator red is good as well.
Turn the key on and measure from battery + to the regulator black wire. Should have a very low voltage, less than 1V is OK; then measure voltage from the regulator white wire (field coil power) to ground, should be close to battery voltage with engine stopped.
Also measure the field coil resistance, with regulator disconnected. I don't know the spec but it should be pretty low - 3 to 5 Ohms maybe? That will be the white wire to ground.
The bullet connectors under the sprocket cover, for the alternator wires, tend to corrode badly because of the temperature cycling and occasional wetting. Have a look at them.

[alecholmez]

Thanks Bodi good to know, so I followed those instructions and here’s what I got:

- When measuring the battery ground to frame I got a really low resistance, about 0.1-0.2ohms
- The connection from battery to regulator red was also good, saw some resistance there but it was low.
- Turned the key on and saw about 0.4V from the black regulator wire
- Measured the white wire and saw about 11.2V but the odd part was it fluctuated from about 6V to 8V and would then settle back at 11.2V. I’m just guessing that’s my #$%*ty multimeter though. 11.2V was about 2V lower than what my battery read
- I measured the field coil resistance and it was 4.9ohms, which seems to be the norm for the 550s.

I checked the bulletin connectors by the sprocket cover and they seemed to be okay but I’ll clean them anyways just to be sure.

[alecholmez]

Still no charging on the bike. I'm beginning to think this entire wiring harness is junk. My turn signals went out and no longer come on at all. Wondering how I could get the charging circuit and ignition circuit back to normal...

[rupaulpierce]

Check the various wires for continuity and the connections in the nylon plug at the rectifier, specifically the red wire.


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[alecholmez]

So I have confirmed continuity on all wires to the regulator rectifier combo unit, and also bought an entirely new one that was designed for lithium ion batteries, still no luck. The power no longer dips down at really high RPMs but it stays constant at 12.4-12.5v. So it’s never going up, I’m really confused at this point. I can see my lights and headlight get brighter when I rev the engine so I know the stator is working, I have absolutely no clue why charge isn’t making it back to the battery. I started just unplugging stuff to see if I had a short somewhere and still no luck.

I also forgot to mention I have a Dyna S ignition with stock coils. I know that draws some more power but it’s not until recently this has been an issue.

[TwoTired]

I would guess, given no real test data, that your lithium battery has been abused enough to enter failure mode, and can't really hold a proper charge.  Lithium tech is not as forgiving of abuse as lead acid.

Or, your new r/r isn't doing the job they promised.

One thing to check, is the black wire voltage going to the VReg, with and without lights on.  And, how much voltage is lost between between battery POS terminal and black wire at the vreg.  To be thorough, you would also check the Voltage lost between Battery NEG and green connection to the VReg.  No VReg is going to properly charge a battery, if it doesn't get an accurate report of actual battery voltage.

Cheers,

[bryanj]

Sounds like your generator is putting out some amps but either not enough or the battery wont take it.
I would start with a KNOWN EXCELENT battery and retest

[Greyhound]

Could this issue stem from the Dyna S ignition system?

More and more I hear about weird electrical issues with Dyna S ignition systems (especially when in use with stock coils).

Do you ever have the issue of running only on cylinders 1 and 4 or 2 and 3?

[bryanj]

Cant answer that i only use points

[TwoTired]

Could this issue stem from the Dyna S ignition system?

More and more I hear about weird electrical issues with Dyna S ignition systems (especially when I’m use with stock coils).

Do you ever have the issue of running only on cylinders 1 and 4 or 2 and 3?

The Dyna doesn't help matters.  The stock points charge the coil through 190 degrees of crank rotation.  The dyna charges them through 330 degrees of crank rotation (using Hondaman's data).  For about 60% more power draw.  So, the dyna becomes a power hog, imo, because it leaves the power on the coils well beyond the time it takes to actually charge them.  The real killer is 3 ohm coils with dyna.   It usually work ok with stock coils, provided you haven't increased power draw with a larger healight or other "extra" electrical loads.

Stock alternator is good for about 150 watts when spun up.  The stock bike draws roughly 10 amps with key switch and lighting on, or about 120 watts drain.
However, at idle RPM the alternator makes about 1/3 of full rated (60 Watts).  The battery will drain faster at idle with the dyna.  But, by 3000 RPM the alternator is close to full output.  Now it is a balancing act of battery drain vs battery charge.  If you only have a charge rate of 20 watts, and an idle drain rate of 60 watts.  You have to ride above 3000 RPM for 3 times longer than any idle period, longer for a dyna ignition.

There's nothing wrong with the stock coil design.  They are actually very efficient.   Any 5 ohm coil will draw more power with the Dyna-s than with points.

There have been many posts about Dyna trigger failure, where one set of coils quit firing.  Sometimes it is temp sensitive.  Fails when hot.  One workaround was to run with the points cover off.  I don't recall that working long term though.

FYI: I'm still using points on all my SOHC4s.  They've been pretty reliable for me. But, I only use TEC brand.

Cheers,

[kaptainkid1]

So i had the same problem on my bike and it turned out to be the key switch which was oxidized on the connector. Therefore the bike wasn't charging properly. So I ran wd-40 and turned the key forcefully on and it on and off and or clean all the contact too. Wire brush the connections between the light bucket and by the fuses, regulator, etc.

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[Deltarider]

... So I ran wd-40 and turned the key forcefully on and it on and off...

That's my routine at the start of every riding season.

[alecholmez]

Okay just for information I’m on stock 5ohm ignition coils with the Dyna S.

So after some cleaning and more digging I found the rectifier clip on the sub harness had melted or something cause it looked like junk, so I replaced that and rewired, but still no charging. Here’s some test data:

With known working battery and also two different ricks combo reg/rec (I’ve tried 3 different batteries):

- Battery charged and rested read 13.2v ignition off
- Black wire to regulator with ignition on read 13.14v (battery pulled 13.15v with ignition on)
- Green and white field coil wires on regulator harness side read 4.7ohms which is okay according to the service manual
- All 3 Yellow stator wires all pulled 1.3ohms of resistance which apparently is way out of spec according to the service manual (0.35ohms)

Signs of a bad stator? The bike has almost 30k miles on it and I’m sure the previous owners have dropped it, it was beat up before I started restoring it

Also my ignition switch is brand new so I don’t think that’s it

[kaptainkid1]

Here is my thread and you can troubleshoot the volt lost either positive or negative side and then work back from there. You're getting a proper charge from the stator?  and from that point the bike harness is the drop in proper charge I'm guessing. Hopefully this will help.

http://forums.sohc4.net/index.php/topic,171783.0.html

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[bryanj]

Appart from mechanical damage from an accident i have NEVER seen an SOHC bad stator, or field coil.
Have seen damaged leads and connectors

[TwoTired]

With known working battery and also two different ricks combo reg/rec (I’ve tried 3 different batteries):

- Battery charged and rested read 13.2v ignition off

What battery type?  That's too high for a Lead acid.

- Black wire to regulator with ignition on read 13.14v (battery pulled 13.15v with ignition on)

Under what condition?
Did you have lighting on?  Loads elsewhere can pull down black wire voltage, if the inline connections/switch have increased resistance.

- Green and white field coil wires on regulator harness side read 4.7ohms which is okay according to the service manual

Yes.

- All 3 Yellow stator wires all pulled 1.3ohms of resistance which apparently is way out of spec according to the service manual (0.35ohms)

Almost certainly measured wrong.   What ohmmeter did you use?  Very low values of resistance need impeccable care and usually specialized equipment.  Did you subtract out the meter lead resistance?  Does your meter have adequate resolution and accuracy to measure such low resistance?

Signs of a bad stator? The bike has almost 30k miles on it and I’m sure the previous owners have dropped it, it was beat up before I started restoring it

If all three branches measured the same, why would they all be damaged in exactly the same way?  Did any of the branches measure continuity to ground?  Can you see axe marks or bullet holes in it?  That's about what it takes to make the stator fail.

Also my ignition switch is brand new so I don’t think that’s it

Troubleshooting electrical circuits by guessing is almost always prone to failure, in my experience.  It's also the most expensive path to resolution.  New things can fail or be of poor quality.  Devil is in the details.  Overlook them and electrical things don't work as expected.  Electrons can be vindictive if you don't treat them in the proper way.

Cheers,

[alecholmez]

All batteries I’ve tried with the bike have been shorai lithium ion batteries.

The condition I pulled the 13.14v was with all running lights on, and no headlight. I’m just trying to get some form of charging before introducing more load. As of right now it’s not circulating any power back to the battery at all.

So I remeasured the stator wires with a brand new digital multimeter, model is Klein Tools MM600 multimeter, since previously I was using a junk harbor freight multimeter, and this time with a good multimeter they all came out at 0.8ohms with the lead resistance subtracted. Also none of the wires of continuity to ground.

The stator cover is pretty beat up but I see no holes or cracks in it. It’s worked before so I have some serious doubts of it being toast. You make a good point it’s highly unlikely they’re all damaged the exact same way. I’m going to give me ignition switch a good looking over

[TwoTired]

All batteries I’ve tried with the bike have been shorai lithium ion batteries.

The condition I pulled the 13.14v was with all running lights on, and no headlight. I’m just trying to get some form of charging before introducing more load. As of right now it’s not circulating any power back to the battery at all.

Have you noted the battery voltage change with RPM?  What RPM does the voltage begin to increase?

The working voltage of a LiFePO4 battery, 4 cell (in series) pack is 12.0 to 13.2V.
An instantaneous battery voltage reading tells you nothing about the charging system unless you look at voltage change trend data.  If the battery is under load, the voltage will show a depleting trend.  If charging, the battery will show an increasing trend.  The battery charge state dominates the system voltage.  The bike can discharge the battery at a 10 amp rate without alternator output. (way more when the estart is used).   But, a 12 amp alternator can, at max, charge the battery at a 2 amp rate and is usually lower at 1 amp while that 10 amp load is present.  At idle RPM, a good alternator can only make 1/3 of is 5000 RPM rating or about 4-5 amps.  At idle, your battery will deplete with the key switch on and alternator spinning.  It will only restore power to the battery when the alternator spins fast enough to overcome whatever electrical load your bike has.

Your charging system should limit the LiFePO4 battery max voltage to 14.1 Volts, in order to treat it well.  Charge controllers for lead acid limit to 14.5 V, which is technically abuse for a LiFePO4 battery.   Also, for maximum LiFePO4 battery life, the voltage should never be allowed to fall lower than 9-10V, or damage can occur.  Lead acid batteries can usually recover when severely depleted.   It's a gamble for LiFePO4 tech about it's survival when overly discharged.   Just note that three abused LiFePO4 batteries may all be damaged.  Or, maybe not.  It's not just voltage that determines a batteries health.  It is voltage held while under full load that is the determining factor.  A damaged battery may not supply full voltage under rated load.

While in the Navy, our parts stock room guy decided to test 1/10 amp fuses with a VOM in common use of the day.  He went through a whole box of testing and declared all his stock bad.  Sure enough, they were.  His meter supplied 1/5 of an amp during each test blowing every fuse he had in stock while he tested them.  Sometimes you need to use your head more often than a test tool.

Cheers,

[alecholmez]

That was great information TwoTired. So previously there was no voltage increase at all so charging was just non-existent. But I actually just sort of fixed haha. I bypassed my harness and ran a wire  from the regulator/rectifier green (ground) to my battery ground and now I have some charging. And it’s limits are correct for lithium ion since I now have the lithium ion compatible ricks regulator rectifier. So I’m guessing I have either a garbage ground somewhere or connector/wire is toast. I’ll keep investigating and report back here. Thanks for all the help again!

[TwoTired]

I'll guess that when you did a voltage test for the black wire at the regulator, you used a ground at or near the battery, assuming all grounds were the same potential.  It's common to do that.  But, it doesn't really tell you what the Vreg is dealing with for measurement of battery status.

Details of troubleshooting are sometimes learned with experience.

Positive voltage routes as well as Negative return routes reaching to source of power are equally important, as you have just experienced.

Looks like you'll have it fixed soon.

Cheers,

[kaptainkid1]

Do a voltage drop test first: place one meter probe on the battery + terminal, and the other meter probe on the regulator black terminal. With the key on, note the voltage. (The engine doesn't have to be running, but you may want to measure both with and without the lights on.) The reading should be less than 1 volt. This method is good start to troubleshoot your low/no charge issue.

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[Spanner 1]

' I ran a wire from the Reg/Rect Green to the battery Neg and now it seems to be charging '. We've had this problem before with aftermarket R/R 's . Folks think you just plug the R/R Green to the Green from the Alternator ( Field coil ) and done . No charging like that  as actually neither wire is at ground potential . The R/R must have a ground reference to work.  Even tho' both wires are Green they are not ' a ground' rather a wire that must be grounded. So, connect the Greens together AND to ground