Not enough charging voltage

[moto_fz6n]

Hello guys,

I searched the different threads on this subject but i was't able to find a solution for my problem. I am new to motorcycling so I am not yet familiar with its electrical/mechanical problems but I want to learn as much as possible ( preferably without having them ) )

The problem I have with my bike is that at idle I have a reading of 12.4 V charging the battery. As I go up in RPM , at around 5000, the voltage increases to a max of 13.5 V . ( single head light - high beam, fan off)

Shouldn't the voltage have a constant value between 14.2-14.9 from idle to 5000 rpm ?

The tests:

-The test were done after 1-2 hours since I arrived from work, so the engine was still warm, and the outside temperature was > 28 degrees C. / 82.4 F

1) Initially I thought the regulator rectifier is faulty so I unplugged it from the bike and started measuring the diodes. I got the 0 V , when it was supposed to be, and values around 0.543 0.550 0.551 when it was the case. (can't remember the exact way I used the multimeter probes but I followed the standard procedure for measuring the diodes. Are the values ok ?

2) Then I went to the generator.

2.1) First test: I checked if there was any continuity between the 3 white wires and the negative terminal of the battery (and the frame/screws any thing that could have been considered a ground) ---> the result: there wasn't.


2.2) Second test: I measured the resistance between the 3 wires, the values were equal, and around 0.5 ohm / 0.6 ohm -----> observation: I know I should get a reading of: 0.22-0.34 ohm at 20 C. Are these values ok ? considering that the outside temperature was greater then 28 degrees C (82.4 F), and the engine was still warm ?

2.3) Third test: With the bike running, and the regulator rectifier disconnected I measured the AC voltage between the 3 white wires from the generator.

​

The values were: 1250 RPM ~ 20 VAC

​

5000 RPM ~ 80 VAC

Can any one help me find out what is the problem ? What other tests should I do ?

Thank you.

 

[TownsendsFJR1300]

The voltage at idle indicates NO charging (your running off the battery).

Typical 5K RPM voltages is close to 14 volts. Mine never touches 14 (when read at the battery) so 14.4 and up, very likely won't happen.

Here's a video of mine, cold start to get an idea what you should be seeing: https://www.flickr.com/photos/127092600@N08/

Others will chime in re testing and likely faults.

And welcome to the forum!!!

 

[FinalImpact]

These are not like a cage charging system and they do not maintain an even voltage. Output from the generator is RPM dependent!

Unlike a car there are no field windings changing the output when a load is sensed, just permanent magnets hence its output is RPM dependent. Ask or search the web if you want to know more.

These are inexpensive charging systems and somewhat robust as cage Alternator would not do well at 17,000 RPM. But clearly they have their limits!

Off hand I would say your only issue is your battery is slightly discharged. Check it after sitting 4hours. It should be close to 13 volts at 70°F.
The short version is this; if your battery is fully charged and the system working correctly you should read about 14vdc >2500RPM.

Look here!
Charging System Overview.. .. ..

12 Volt Battery ~12.72V:
A fully charged 12 volt lead acid battery is ~12.72 - 12.95volts! It needs at least 13++ Volts from the charging system to stay charged! Yamaha specified a "no-load output from the charging system of 14.1 - 14.9vdc. (( Each cell is ~2.12V X6 = 12.72 ))

HEALTHY BATTERY = something like this:
12.95V - Battery voltage, engine off for 30 minutes to 30 days
12.82V - 1300 RPM - fan off, may be higher with single headlight
14.30V - 2500 RPM - fan off, but less than 14.5V above 5000 RPM

Battery Voltage can be checked from the RR w/the seat off:
Shown is Cold start, @ 1500 RPM, 14.4vdc



DURING STARTUP - EXPECT something like this:
KEY ON = 12.00V +0.35V/-0.50V (not cranking)
CRANKING = 10.50V +0.25V/-0.50V i.e. start button depressed & cranking. It's normal for the battery to drop about ~1.5V from static no load to cranking. NOTE: Batteries are temperature sensitive. As their temps drops, so does the voltage. As their temp increases, so does their voltage.


End Paste from link above...

 

[moto_fz6n]

These are not like a cage charging system and they do not maintain an even voltage. Output from the generator is RPM dependent!

Unlike a car there are no field windings changing the output when a load is sensed, just permanent magnets hence its output is RPM dependent. Ask or search the web if you want to know more.

These are inexpensive charging systems and somewhat robust as cage Alternator would not do well at 17,000 RPM. But clearly they have their limits!

Off hand I would say your only issue is your battery is slightly discharged. Check it after sitting 4hours. It should be close to 13 volts at 70°F.
The short version is this; if your battery is fully charged and the system working correctly you should read about 14vdc >2500RPM.

Look here!
Charging System Overview.. .. ..

12 Volt Battery ~12.72V:
A fully charged 12 volt lead acid battery is ~12.72 - 12.95volts! It needs at least 13++ Volts from the charging system to stay charged! Yamaha specified a "no-load output from the charging system of 14.1 - 14.9vdc. (( Each cell is ~2.12V X6 = 12.72 ))

HEALTHY BATTERY = something like this:
12.95V - Battery voltage, engine off for 30 minutes to 30 days
12.82V - 1300 RPM - fan off, may be higher with single headlight
14.30V - 2500 RPM - fan off, but less than 14.5V above 5000 RPM

Battery Voltage can be checked from the RR w/the seat off:
Shown is Cold start, @ 1500 RPM, 14.4vdc



DURING STARTUP - EXPECT something like this:
KEY ON = 12.00V +0.35V/-0.50V (not cranking)
CRANKING = 10.50V +0.25V/-0.50V i.e. start button depressed & cranking. It's normal for the battery to drop about ~1.5V from static no load to cranking. NOTE: Batteries are temperature sensitive. As their temps drops, so does the voltage. As their temp increases, so does their voltage.


End Paste from link above...

I read that topic a few days ago but for some reason now it makes more sense )). so thank you

I will do the following steps and hope for the best )

-take the battery out, and charge it
-let it sit for a few hours to stabilize
-start measuring the voltage, if the values are ok, then when I will put it back on the bike

Now, if the charging system is fine, and the battery is fine, I should see voltage values close to the ones from the topic, right ?

 

[moto_fz6n]

The voltage at idle indicates NO charging (your running off the battery).

Typical 5K RPM voltages is close to 14 volts. Mine never touches 14 (when read at the battery) so 14.4 and up, very likely won't happen.

Here's a video of mine, cold start to get an idea what you should be seeing: https://www.flickr.com/photos/127092600@N08/

Others will chime in re testing and likely faults.

And welcome to the forum!!!

Thank you, I will use it as reference

 

[moto_fz6n]

The voltage at idle indicates NO charging (your running off the battery).

Typical 5K RPM voltages is close to 14 volts. Mine never touches 14 (when read at the battery) so 14.4 and up, very likely won't happen.

Here's a video of mine, cold start to get an idea what you should be seeing: https://www.flickr.com/photos/127092600@N08/

Others will chime in re testing and likely faults.

And welcome to the forum!!!

Thank you, I will use as reference

 

[FinalImpact]

Mine seems to run higher than some. But in the realm of 13.8v to 14.4v would be good to see above 2500rpm.
You might have the battery load tested while out. Its 10A battery and I'm guessing here but 220cca??? Something like that!

 

[moto_fz6n]

That's a good idea, I'll search for a garage to see if they can test the battery. Indeed it is a 10 amp battery but I don't know the cca.

I left my bike at wok, so yesterday when I went to get it back, before I started the bike I hooked up the multimeter, and I noticed the following:

-after a day of sitting the battery voltage was 12.1
-when the lights and fuel pump came on, the voltage dropped to 11.95 V
-when the bike started the voltage dropped some more, to 8.68 V

During my ride home, I used the horn a couple of times and then it went dead. For a couple of minutes I maintained the engine RPM at approximately 4000 and the horn was alive again )

After I got home I removed the battery and connected to a charger. Unfortunately I only have a car charger with an output of: 14-15.8 volts and ~ 4 amps. I let the battery charge for ~ 1 hour, then a 1/2 hours break, and another 1 hour. I hope I did not damaged the battery to bad.

Is it ok if a charge the battery with the current charger, or 4 amps is to much for motorcycle batteries ?

 

[FinalImpact]

I wouldn't do it to a new battery. But if you're going to hit it with 4 Amps, you did the right thing.

Charging a 10 amp battery from dead would imply 1 Amp per hour for 10 hours.
Yours being what 20% of capacity you did the right thing with the charger you have. The main thing is heat damage. If the charging process makes the battery hot, stop charging. But back to that 20% of capacity.
Lets say it needs 8 Amps to bring it to 95% capacity and you use that 4 Amp charger. 8 Amp / 4 Amps per/hour puts you at 2hr charge time which you did over 2 sessions.

Question; did it actually take a charge and hold it?

EDIT:
What was its voltage after being charged? Better question, how quickly did the voltage climb while charging?

Point: current charges batteries. If the voltage stayed low and then peaked at 14.5v an hour later, it likely took a charge. If the voltage instantly shot to 14+ your battery is junk and should be replaced.

 

[moto_fz6n]

After being charged it was around 12.7 .

While charging, the voltage shot instantly to 14+ in less then 20 minutes, and maintained that value during the "charging process"; I have a crappy charger, maybe if I'll get a CTEK I will save the battery.

I don't think it took the charge becaue I measured it after 18 hours, and the voltage dropped 12.5 V (I put it back on the bike, but I did not start it, I don't want to keep the battery in my house longer than it is necessary).

Today before I left for work, I measured the battery and it was 12.41 V (after another 18 hours since the last measurement). While the engine was cranking the voltage dropped tot ~ 8.85 V.

But, something odd happened: the charging voltage was 14.29 V, from idle to 4000 rpm :O:O, what happened ?

Unfortunately the happiness was very short, because I took another measurement at work, and at idle was ~ 12.5 and 13.05 at 2500-4000 rpm (no fan, only 1 headlight + tail ligght)

What is happening ?

 

[TownsendsFJR1300]

Get the battery LOAD TESTED and stop the guess work...

If a new battery is needed, charged fully, THEN installed, you can check your running voltage with solid results.



BTW, I bought the 4.3 CTEK charger ( CTEK 0.8 Battery Charger - CTEK Battery Chargers Multi US 4.3 ).
I like the charger, (my favorite actually-have 2, one for the boat, one for the bike).

Don't count on it restoring your battery. In the re-store mode, it bumps up the charge into the mid 14's
(and didn't save my borderline 3 year old Yuasa)

 

[FinalImpact]

Did it get hot or warm while being charged?

It sounds like the battery is done being a contributor to the FZ and needs replaced.
I've extended the life of few batteries by discharging them and fully recharging them a couple times.
You could try it, but its time-consuming.

It seems like your battery is older and sulfated. Needs replaced. =(

 

[moto_fz6n]

Did it get hot or warm while being charged?

It sounds like the battery is done being a contributor to the FZ and needs replaced.
I've extended the life of few batteries by discharging them and fully recharging them a couple times.
You could try it, but its time-consuming.

It seems like your battery is older and sulfated. Needs replaced. =(

Sorry for wasting the time, I just noticed that it's the original battery, so no point in testing it and measuring it, I'm surprised it still cranks the engine. I will get a new one. So next question: can I get a 12A one? What is the minimum/ recommended cca ?

 

[Motogiro]

After being charged it was around 12.7 .

While charging, the voltage shot instantly to 14+ in less then 20 minutes, and maintained that value during the "charging process"; I have a crappy charger, maybe if I'll get a CTEK I will save the battery.

I don't think it took the charge becaue I measured it after 18 hours, and the voltage dropped 12.5 V (I put it back on the bike, but I did not start it, I don't want to keep the battery in my house longer than it is necessary).

Today before I left for work, I measured the battery and it was 12.41 V (after another 18 hours since the last measurement). While the engine was cranking the voltage dropped tot ~ 8.85 V.

But, something odd happened: the charging voltage was 14.29 V, from idle to 4000 rpm :O:O, what happened ?

Unfortunately the happiness was very short, because I took another measurement at work, and at idle was ~ 12.5 and 13.05 at 2500-4000 rpm (no fan, only 1 headlight + tail ligght)

What is happening ?

In addition: Important! Wear safety eye wear when working with batteries!
Because you're seeing the voltage changing quickly you may have an intermittent connection. This intermittent may be internal between the cells or the terminals. Make sure your external connections to the battery are clean and tight.

The other problem could be a poor tester or procedure. It sounds like your test voltages are very inconsistent. Because we are using voltage only as a reference they should be fairly stable except for rising during rpm increase.

This sounds suspicious: the charging voltage was 14.29 V, from idle to 4000 rpm :O:O, what happened ? This sounds like there was no load from the battery or the bike and you were looking at voltage from the charging system only with no battery connected. You would think a no connection with the battery would yield 14.9-15 vdc but the shunt in the R/R may have been very hot.

The ability of the battery to be viable in the bike is also dependent on it's ability to deliver current. If the battery can operate in the 12 volt nominal range with the ability to deliver current for all the functions required there is no reason to abandon it right away. This is why a load test is important. Charge the battery fully and then have it load tested. If you suspect an intermittent connection internally within the battery do not use it any more. Just replace it with a new one.

It's also important to understand that on the bike, voltages are dependent on load. This includes a battery that is requiring a charge. The battery acts as an additional load when it requires charging and so you will see the voltages at a lower value when it needs a charge. Once the battery is at it's healthy state of charge the voltages from the charging system will return and stay at the higher normal values.

 

[FinalImpact]

Sorry for wasting the time, I just noticed that it's the original battery, so no point in testing it and measuring it, I'm surprised it still cranks the engine. I will get a new one. So next question: can I get a 12A one? What is the minimum/ recommended cca ?

You can but.....
Watch the ratings. Some of the 12Amp/hr batteries actually have lower CCA than the OEM 10Amp/battery.

No worries. Its all educational!
PS do not charge new battery w that charger! You need slow and longer... 1.5 amp / hr charger.

 

[moto_fz6n]

I heard that you need to activate the battery after you buy it, but now it makes sense. Since I don't have a good charger I'll ask the guy at the shop to mix the "substances" and charge the battery for a couple of hours until is all good. In my country Varta, and Bosch batteries are not very good (what about in USA ? ), other options I have are: Yuasa, Landport, Exide. What do you recommend ?

 

[TownsendsFJR1300]

I'd stick with the Yuasa myself.

And yes, a freshly filled battery is 80% charged. You can use it right then but you'll limit the overall life in the end.

They usually do a 1.25 amp charge and can take up to 6-8 hours trickle charging to 100%.

If their a regular shop, they SHOULD, be doing this. I'd ask to make sure...

 

[FinalImpact]

I'd stick with the Yuasa myself.

And yes, a freshly filled battery is 80% charged. You can use it right then but you'll limit the overall life in the end.

They usually do a 1.25 amp charge and can take up to 6-8 hours trickle charging to 100%.

If their a regular shop, they SHOULD, be doing this. I'd ask to make sure...

In addition to the above. Once filled it should sit for about 4+ hours before being charged... Overnight is fine.
Yuasa comes with a filler kit which is spill free. You just need it charged.

 

[moto_fz6n]

I wanted to get a Yuasa but it wasn't available right away and I need the bike so I got an EXIDE battery. I know you can't compare the two of them but considering the low price I paid for it, if it lasts 1-2 years it's ok.

Before I gave the old battery to be recycled, I asked the guy from the shop to test it. The conclusion is that the battery was 77% "alive" ), and it was capable of 125cca. I wasn't paying to much attention to the testing device, but on the screen it said something like: "bad battery, replace it...."

With the new battery I had a charging voltage of 13.0x at idle, and it was rising with the rpm but I can't remember the exact values under 5000 rpm. At 5000 rpm it was 13.91 V. - fan off, 1 head light - low beam..

I will keep measuring the charging voltage for a couple of days just to be sure I don't have other problems with the charging system, but I think it should ok, right ?

 

[TownsendsFJR1300]

I wanted to get a Yuasa but it wasn't available right away and I need the bike so I got an EXIDE battery. I know you can't compare the two of them but considering the low price I paid for it, if it lasts 1-2 years it's ok.

Before I gave the old battery to be recycled, I asked the guy from the shop to test it. The conclusion is that the battery was at 77% "alive" ), and it was capable of 125cca. I wasn't paying to much attention to the testing device, but on the screen it said something like: "bad battery, replace it...."

With the new battery I had a charging voltage of 13.0x at idle, and it was rising with the rpm but I can't remember the exact values under 5000 rpm. At 5000 rpm it was 13.91 V. - fan off, 1 head light - low beam..

I will keep measuring the charging voltage for a couple of days just to be sure I don't have other problems with the charging system, but I think it should ok, right ?

Your charging voltages are pretty close to normal. Looks like your good..

I posted this earlier in your thread, the charging voltages of mine (with a border line battery) to compare (dual head light mod too):

https://www.flickr.com/photos/127092600@N08/