battery totally discharged, twice

[Steinrawr]

Good day friends,
I have an issue I want to run by you.

I have a 05' fz6, that I bought 18 months ago. Since then I haven't had any issues with it. It always starts, and the previous owner also confirms he never had any problems. Even after 6 months of storage it started on the first crank.

Now, since July i have experienced that the battery has been totally discharged, twice. After the first time i freaked out (and luckily my In-laws could pick me up with a trailer) and just replaced the battery. I guess the old battery had been in the bike at least 6 years.

Now I have a new, high end battery that was just installed, but this morning the bike was totally discharged again.

I have not been riding short trips, but the bike has been unused for a few days. I don't have any equipment that consumes power other than standard alarm.

Any idea what this might be? I'm thinking a faulty alternator.

Thanks for any help!

 

[ozgurakman]

We're experiencing same issues on my buddy's fz6. Because of I have the same bike model, we changed the parts of our bikes and diagnose it quicly.R/R is fine, battery is fine but his bike's alternator has weak power.

When you measure your bike's alternator with an ampmeter, you should see 2.5 - 3.5 ohm at 20 celcius. And all of phases ohm value SHOULD be same. But, my bike is out of that ohm range (I read 1.2 ohm on ohmmeter) and it charges very fine. I think if my multimeter is broken or ohm value is not crucial.

There is another way to check alternator health:

Pull the R/R's connector, start the bike. Your bike is running from your battery now (you need a charged battery.)
Now rev the bike to 5k rpm and check your alternator voltage from R/R connector (there is 3 white cable on connector and you should use AC 200V mode on multimeter).
Ideal voltage is AC 80V per a phase at 5000 rpm. (My bike's alternator's each phase is 78).

Now this is the point: My buddy's bike's alternator's phases are 78,78 and 72 V AC. you can see, a phase's power is low than others. So there will be an alternator replacement or it's wires should be changed (repair).

Good luck. If you check the bike and write your values here, we're here to help.

I almost forgot: R/R voltage is 14 V DC @ 5000 rpm.

 

[FinalImpact]

Given this problem I would grab a 12v test lamp and use it as a diagnostic aid. Although any small incandescent lamp could be used. Turn the ignition off as well as any/all accessories. Disconnect the NEG lead from the battery and place the test lamp across the NEG battery post and the Neg Lead you just disconnected. In the Ideal world the lamp will be OFF indicating there is no current flow (GOOD).

If the lamp is dimly lit, there is current flow and we need to know where it comes from. With the ignition off, it leaves only a few options. The Gauge cluster, the alarm, and the Regulator Rectifier.
Begin by removing fuses and looking for the Test Lamp to go out. Take note of which fuse changed the lamps condition. If none of the fuses did anything, unplug the RR. Did the test lamp go out? If yes, the leakage current (potential source of battery drain) is the RR.

IME, looking at stator output voltage without a load is not going to show useful information (Variance could be as much as +/-25vac and still work fine). Leave it plugged in and measure the the three white leads (AC Volts) while its doing work with a load. Even then I would not be concerned if they were a +/-10v of each other. More than that and I may be more concerned but that in itself is not going to keep it from working.

Also, battery voltage as measured while the charging system is working is very dependent on the battery charge.
Low battery needs a charge: It could show 13.7v which means the system is charging.
Full battery needs NO charge. It could show 14.3v which means the system is charging but most of the energy made by the stator is going into the regulators shunt and being dissipated as heat (normal for a fully charged battery).

As for Ohm meters - use the lowest range possible and depending on the meter, you need to subtract the resistance of the test leads connected to the meter. i.e. touch the test leads together. Ideal = 0.0 ohms. Reality is the leads have resistance and will show something like 0.65 ohms of resistance when the leads are touched together. Subtract the "leads touched together" from the stator leads measurement.

Example: leads touched using lowest ohm setting displays 0.50 ohms.
If we measure the Stator and get 2.50 ohms, we subtract the leads reading of 0.50. OR Stator + Leads - minus leads = actual value.

 

[Steinrawr]

Hello folks.

Thanks for the replies.

As of now I've done some research, and I've ended up ordering a new stator.

I measured the stator connectors to about 5-6 Ohm, (after subtracting the leads resistance). I also did a live voltage test, with the following result.

Connector/RPM	1500	3000	7000
A	10v	12v	14v
B	10v	12v	14v
C	10v	12v	14v

Also i did a check on the battery itself (brand new). The level on the battery was a little low (12.0v) but, i did not get it much above 13.4-13.9 when revving.

I did not check for leaks, but there is only the alarm as standard connected.

I hope I solve it by switching stator. Or do you disagree?

 

[FinalImpact]

A bad stator won't drain the battery. It may not charge it effectively or at all if its bad, but it is not the source of discharge when the bike is sitting.

The battery appears to need a charge. Charge overnight, allow it to sit for several hours. If it maintains ~13.0 - 12.85vdc, do your testing. Keep in mind it current that charges a battery not voltage. Voltage simply tells a little about its state of charge.

I guess the question is: is not being fully charged or is it being drained while at rest?

 

[Motogiro]

Hello folks.

Thanks for the replies.

As of now I've done some research, and I've ended up ordering a new stator.

I measured the stator connectors to about 5-6 Ohm, (after subtracting the leads resistance). I also did a live voltage test, with the following result.

Connector/RPM	1500	3000	7000
A	10v	12v	14v
B	10v	12v	14v
C	10v	12v	14v

Also i did a check on the battery itself (brand new). The level on the battery was a little low (12.0v) but, i did not get it much above 13.4-13.9 when revving.

I did not check for leaks, but there is only the alarm as standard connected.

I hope I solve it by switching stator. Or do you disagree?

Did you do your stator voltage test using the meter in a ac volts mode? This very important. If you did it in DC volts mode the reading will be inconclusive. The resistance test of the 3 legs of the stator are the most important. The other test you must do with the ohm meter is measure from each leg of the stator to engine or chassis ground. There should be no reading at all. If there is a reading to ground the stator is damaged and needs to be replaced.
As previously mentioned by FI the AC voltage test doesn't tell you the health without knowing what power is produced under a known load.

 

[Steinrawr]

Thanks for your input motogiro.

I did the test with the AC mode. There is no ground, but a very high ohm-reading on the wires. Also very low voltage from the alternator. I know it doesn't tell everything, but it is disturbing that my highest reading is 14v, when all research I've done tells me it should rise evenly with the RPM from 15/16v up to 100v directly from the stator.

I'm doing a third test today to confirm my previous results, and give the connectors some cleaning with Electronics cleaner spray.

 

[FinalImpact]

Cliff,
Any chance some meters may interpret AC signal differently than others based upon its RMS reading? As in, most meters look for 50-60Hz and create and RMS voltage. That said, if I were more ambitious I'd look up the formula and see if the phase is even part of the equation!

Initially my take on this issue was it was discharging while off. If its DC output is ~14V above 2500RPM, thats about par for course on a slightly discharged battery. As I stated before, a fully charged battery will show higher peak DC voltages as the value is dependent on the battery state of charge.

Battery Low state of charge = lower voltage as more current is being used to charge battery
Battery High state of charge = Higher voltage as less current is being absorbed by the battery

 

[Motogiro]

Cliff,
Any chance some meters may interpret AC signal differently than others based upon its RMS reading? As in, most meters look for 50-60Hz and create and RMS voltage. That said, if I were more ambitious I'd look up the formula and see if the phase is even part of the equation!

Initially my take on this issue was it was discharging while off. If its DC output is ~14V above 2500RPM, thats about par for course on a slightly discharged battery. As I stated before, a fully charged battery will show higher peak DC voltages as the value is dependent on the battery state of charge.

Battery Low state of charge = lower voltage as more current is being used to charge battery
Battery High state of charge = Higher voltage as less current is being absorbed by the battery

Exactly why there can be different readings. AC voltage measurement is okay as an addition to trouble shooting but should not be the only test and would also be more telling under a known specific load. Taking it a step further into possible misinformation could be the leg that is producing current in relation to inductive reactance and what effect that has on changing impedance of the other windings. So yes, we could develop an AC test voltage if each leg has a simultaneous, specific load/resistance so that inductive reactance emulates the stator under it's charging load. Still we might add full wave rectification with an added capacitor to filter ripple and do a dc test on each leg! Or we could do the resistance test..... Lol!

 

[FinalImpact]

IIRC mine was around 20VAC RMS at idle while producing rectified DC out around 13.85V. That was on a fully charged battery with stable off voltage of 12.99V.

Does the phase and cycles per second matter with a hand held meter and reference to AC RMS measurements?


OP have you looked at this? -->> Batteries, Charging & the Regulator Rectifier

Or this: LEAKAGE CURRENT KILLING YOUR BATTERY??

 

[Motogiro]

IIRC mine was around 20VAC RMS at idle while producing rectified DC out around 13.85V. That was on a fully charged battery with stable off voltage of 12.99V.

Does the phase and cycles per second matter with a hand held meter and reference to AC RMS measurements?

RMS (Root Mean Square) is the average reading as apposed to peak to peak reading and yes phase relationship and frequency will often effect your reading. This again is a reason I like to reference the resistance test for diagnosing our stators.

 

[Steinrawr]

Sorry, I forgot about this thread for a while.

In retrospect i suspect my stator was not at fault: I did not know of parking lights when the key is turned beyond the steering lock. That might have drained it.

 

[TownsendsFJR1300]

The US version bikes don't have the parking light option....

Another difference along with the immobilizer!!

Tks for the update in either case...