Topic: Battery is not charging

[77cb550f]

I was hoping you guys could help me out because I don't know what else to do. I have a 1977 CB550F and the battery will not keep a charge. I have replaced the following: the battery, stator, fly wheel rotor, regulator, and rectifier. None of this has helped, and I have run out of ideas. Any help would be greatly appreciated. 

[TwoTired]

Any mods to the bike's electrical and/or accessories?  (Big headlight, 3 ohm coils, etc.)

Do you have a multimeter and know how to use it?

Do you have a separate battery charger?

[77cb550f]

There are no mods that I am aware of. I have an ohm meter and when I connect them to the battery terminals after the battery has been charged it reads 12.5 - 13 volts, but then it slowly drops until the bike dies and will not start. And yes, I have a separate battery charger.

[TwoTired]

Ominous start.  An ohmmeter measures resistance. A voltmeter measure voltage.  They can both be inside a single multimeter and selectable with a function knob (or buttons).

Do you know what voltage is on the black wire going into the Vreg?  Key switch on.
Do you know what voltage is on the white wire coming out of the Vreg to the Alternator field? Key switch on.
Can you measure the voltage drop between the battery POS terminal and the VReg Black wire terminal?  (Headlight on).
Can you measure the voltage drop between the battery NEG terminal and the VReg Green wire terminal?  (Headlight on).

Have you measured the Field coil resistance?

To save the battery during most troubleshooting I often remove the headlight fuse to reduce the battery drain.  After repair is done, then put it back in.

Cheers,

[77cb550f]

Thanks for the advice, but I must be honest that I really don't know how to do any of that. I am 17 and this is my first motorcycle. I'm not sure if mine is a multimeter but I could post a picture of the one I am using if that would help? Thank you for the help, and I am sorry for being so ignorant. Hopefully you can explain some of that in a way I can understand, or maybe talk me through it?

However, I think with a little help I should be able to catch on fairly quickly. I have been riding and working on dirt bikes all my life, but I have never dealt with anything electrical.

Also, I just replaced the stator, rotor, rectifier, and regulator tonight and I only jumped the battery and let it idle, hoping that the charging system would charge the battery. After the jump, with the bike running, the battery read 12.5 - 13 on the meter. When I rev the engine it will jump up to about 14.5.  I just read though that it doesn't charge the battery unless it is at 3,000 + rpms. Could that possibly be why it still isn't holding a charge?

[crazypj]

It doesn't have a rotor in normal sense, it has a stationary field coil and rotating 'fingers'
 I've never seen 550 rotor fail, even after major crashes (stator and field coil are a totally different matter though  )
 When you say you replaced it, do you mean you replaced it or did someone replace it for you?
 Was it new/reconditioned or just 'different' (new to you)
It may be someone has fitted a high wattage headlight bulb plus 'race' coils causing excess draw?
 It sounds like its charging OK, is it 14.5V around 5,000rpm?

[77cb550f]

Yes it is around 5,000 rpms when it reaches 14.5. I believe that the head light and coils are original. If pictures of anything would help I can take some. The bike only has 8,600 miles on it and it has sat in storage since 1982. It looks and runs great, I just can't figure out this electrical problem.

[Frostyboy]

I'm gonna stick my neck out here & suggest that battery is dodgy.
(In case that's just Aussie slang dodgy = questionable)

[TwoTired]

The charging system doesn't make enough power to charge the battery at idle.  The alternator only makes about 40-50 watts at idle.  It makes about 150 watts at 5000 RPM.
The bike uses about 120 watts whenever the key switch is turned on, so the battery actually depletes at idle.

Even when the bike is revved to 5000 RPM the battery is only charging the battery at a 1-2 amp rate.  It's nominally a 12 amp hour battery.  So, a depleted battery will take 6-12 hours at 5000 RPM to recharge from the bike.  This is why the charging system is checked with a fully charged battery, and why I asked if you have a separate battery charger to top up the battery without the bike running. This bike's charging system is more to maintain a battery rather pump up a dead one.

FYI, don't run the engine stationary at 5000 RPM to charge the battery.  It is an air cooled engine, so a fan would be needed or a good long run on the freeway.

The electric start uses a bunch of battery power, somewhere between 50-120 amps.  You have to run the engine above 3000 RPM 10-30 times longer than you held the starter button depressed, in order to restore the battery.   These bikes were made to be ridden, not sitting at stoplights idling.

You have a new battery?  Or, an old used one?

Cheers,

[dave500]

umm?the new parts?were some of them used,like the regulator?maybe two dead ones in a row?

[77cb550f]

umm?the new parts?were some of them used,like the regulator?maybe two dead ones in a row

The part weren't actually new. They were used parts off of ebay that were supposedly bench tested to be good. So there is a possibility that I replaced a bad part with another bad part.

You have a new battery?  Or, an old used one?

I'm gonna stick my neck out here & suggest that battery is dodgy

The battery is brand new. I just replaced it about a week ago.

To TwoTired:
Thanks for the info. I fully charged the battery last night so I will ride it today and see what happens. My question is this: Even when I am riding I do not normally ride at 5,000 rpms. I am normally just cruising slowly in the country. Also, I was hoping to use this bike as a daily drive to take to school, but that means lots of town driving at low rpms. So will I always have an issue with a dead battery even if the charging system is working correctly? 

[75cb550 (kyle)]

no. i ride mine to work every day. that's all in town. i would just ride normally instead of trying to achieve a certain RPM for charging purposes. mine can sit for several days and still fire up with the start button.

another battery question? was the battery full when you got it or did you have to fill it yourself? following those instructions are pretty crucial when giving her the intial charge.

[77cb550f]

I had to fill the battery myself, but I followed the instructions exactly like they said. It said to charge it for 2 hours on a 2 amp charger, and that is what I did.

[cameron]

http://www.batterystuff.com/batteries/motorcycle/sYT12C.html

it is expensive, but it will change EVERYTHING.

Keep your existing batt on the tender as a spare. But you wont need it.

[camelman]

Before you buy anything else, check that main fuse coming in from the alternator.  I just went through the exact same thing with a 500F (pretty much identical charging system), and found that the incoming fuse from the alternator was dirty. It was so dirty that it started to melt!  I cleaned off the fuse ends and the receiver ends with sand paper and put dielectric grease on the contacts, and my charging issues completely disappeared. 

Camelman

[75cb550 (kyle)]

hmm... when i first started riding mine, i had to charge it every day. after about a week of regular riding, no issues.

[75cb550 (kyle)]

that was gonna be my next question. what shape is the wiring in? corrosion?

[77cb550f]

Where are the fuses located that I should look at/ clean? I'm not sure but I think the issue may be gone. I fully charged the battery over night, rode it some today, and with the bike off the battery is still reading 13.3. I would still like to clean all the fuse connections though just to be safe.

[75cb550 (kyle)]

fuse panel is behind left side cover on the '75. should be same on yours. not a bad idea to clean and add dielectric.
i would just ride it and see how she goes. probably be fine.

[TwoTired]

There are no fuses in the charging system.  Guys, check the schematic!
And, there is STILL no such thing as a CB500F.  It was never made by Honda.

The Vreg gets the same power as the rest of the bike.  If the main is blown, nothing works.


With a red line of 9200 RPM, don't be afraid of twisting the throttle.  In fact, around town I don't feel safe unless the engine is at least 3500.  The throttle is an escape from other driver threats... IF you have it in gear to make power in the engine's power band.

You really shouldn't be draining the battery unless you keep the RPM down below 2000-ish.  ...which is only at stops, normally.  I commuted 7 miles to work for more than 15 years without battery charge issue, (except when the battery wore out, of course.)

Beginning with a fully charged battery make yourself a chart.  Measure the battery voltage at idle, 2000, 3000, 4000, and 5000 RPM.
As the RPM increases the battery should at least trend toward higher voltage.  As the battery receives charge, it's voltage increases.   The chart you make will tell you at what RPM the charging system overcomes the standard load of the bike and charges the battery.  You can use that information while driving to know if you are in depletion mode or recharging mode.

It is possible that all your connections, switches, and fuse contacts have oxidized, which will reduce the voltage going to the regulator,  This reduces the power that the alternator can make at any RPM.  It is also why I asked you to check the voltage that the Vreg is getting from the battery.
 The alternator needs some power to make power.  Cheat it for power, and it makes less, and the battery can starve.

Cheers,

[75cb550 (kyle)]

for the record, i just told him where the fuse panel was. i must have missed the part about an alternator fuse...
 

[77cb550f]

where is the main fuse located?

[75cb550 (kyle)]

in the fuse panel. i think mine is 2nd from the right if i remember right... if its running your main fuse is fine, though. once they pop they're gone. all your fuses should be under that right side cover, i believe. (if its the same as the 75)

go to the website link and check out the the manuals under cb500

[77cb550f]

Also, ever since I changed out all of those components the neutral light will not come on when I put the bike in neutral. Now I have to pull in the clutch to start the bike. Any ideas?

[camelman]

That fuse exists on the 500FFFFF (for clarification purposes so you do not think I am talking about the 500T).  It is the main fuse.  When it was dirty on my bike, it created a dead battery situation.  I never called it a charging system fuse.  It does physically reside between the battery and the alternator, but I will call it the main fuse coming in from the battery if you want.

We also had to re-solder a connection on the regulator... or rectifier... can't remember at the moment.  That, on its own, did not fix our charging issues, but everything came back into place once the fuse connection was fixed.

Camelman

[TwoTired]

Fuses for the The Cb550 F are under the left side cover.  There should be A black box under that side cover.  The black box contains the fuses and it has it's own cover to help keep the elements from getting to it.  The black cover is often discarded by POs.

There should be 5 positions of fuses on the 77.  The spares are located at each end.  The 15A fuse is the main.

Let us know what your voltage/RPM chart looks like.

[TwoTired]

That fuse exists on the 500FFFFF (for clarification purposes so you do not think I am talking about the 500T). 

You have quite a collection of fictional bikes.  500T is a twin and discussion of this belongs in other bikes.

US model CB500 was offered in 71, 72, and 73.  They were K0, K1, and K2 respectively.

In 74, the CB550 (K0) was offered.  The K model 550's continued thru 78.

In 1975 the CB550 F was introduced and the F model was offered up to 77.

Info source is a book published by American Honda motor co. called the Honda motorcycle identification guide.

I suspect that some have assumed that the CB500 Four side cover badge, with it's over sized F in Four, mistakenly call it an F model.

However, I have to assume that anyone thinking or saying they own a CB500F simply doesn't know what they are talking about, to put it bluntly.

Cheers,

[crazypj]

 I had a 1978 CB550F2.
 Pretty much exactly same as F1 except for BNG (Bold New Graphics) 

[75cb550 (kyle)]

in the fuse panel. i think mine is 2nd from the right if i remember right... if its running your main fuse is fine, though. once they pop they're gone. all your fuses should be under that RIGHT side cover, i believe. (if its the same as the 75)

go to the website link and check out the the manuals under cb500

wow i wish i could say i forgot which side it was on... its worse, i still dont know my left from my right....

[camelman]

That fuse exists on the 500FFFFF (for clarification purposes so you do not think I am talking about the 500T).  

You have quite a collection of fictional bikes.  500T is a twin and discussion of this belongs in other bikes.

US model CB500 was offered in 71, 72, and 73.  They were K0, K1, and K2 respectively.

In 74, the CB550 (K0) was offered.  The K model 550's continued thru 78.

In 1975 the CB550 F was introduced and the F model was offered up to 77.

Info source is a book published by American Honda motor co. called the Honda motorcycle identification guide.

I suspect that some have assumed that the CB500 Four side cover badge, with it's over sized F in Four, mistakenly call it an F model.

However, I have to assume that anyone thinking or saying they own a CB500F simply doesn't know what they are talking about, to put it bluntly.

Cheers,

Yay for you.  Able to ejaculate quotidian information on a whim.  Get over it.  I love my CB500FFFF.  I'm going to love it even more when I get the rebuilt swingarm back from Hondaman.

By the way, TT, check out this link.  It is Merriam Webster's definition of "tact".  http://www.merriam-webster.com/dictionary/tact

Perhaps you can study the definition of "tact" with as much zeal as you study your quotidian Honda model knowledge.  Then, maybe you can reread my comment on why I put the "F" after CB500 and stop being so pedantic.

Camelman

CB350F daily rider
CB350 customer custom cafe in process
CL350 customer restoration in process
Dream 305 customer rebuild in process
CB400F #1 sold
CB400F #2 customer cafe build in process
CB450 customer resto sold
CB500FFFFFFFFFFFFF customer rebuild almost complete
Among others...

Just in case - Pedantic: Characterized by a narrow, often ostentatious concern for book learning and formal rules

[TwoTired]

I had a 1978 CB550F2.
 Pretty much exactly same as F1 except for BNG (Bold New Graphics) 

1975 CB550 F  (F0)
1976 CB550 F  (F1)
1977 Cb550 F  (F2)

I've no doubt some of the F2s were sold in 1978.  But, they were still 1977 models, and almost certainly said so on the head stock. (At least in the US.)  Euro models were probably a different story.

The F2s had different forks along with no accordian boots, a black seat, darker gauges, and of course different colors.

Or, are you saying that American Honda Motor co. printed wrong information in the Identification guide for their bikes?

Cheers,

[crazypj]

It's a European one, I lived in Britain at the time and had a collection of 550's (F1, F2, K3)
 F1 is in avatar
 I still have F2 frame but sold engine out of it in 1986.
My brother had the K3 for a long time, don't remember what happened to it (wasn't really my type of bike, just seemed a good idea at the time)
 I still have house in Britain and about 20+ bikes in various stages of 'restoration' (in lots of pieces, spread out everywhere  )