Author Topic: Battery/charging issue (Read 6251 times)

GrandRapids750K3 · « **on:** March 11, 2012, 11:00:58 AM »

So I threw my fully charged battery in fur days ago and went for a short ride. Came out today to fire it up and the battery didn't have enough juice to use the electric start and I could only limp around the block with no head light or blinkers...

So... Some help diagnosing would be helpful. It's a 73 750K that got a new harness last year and everything appears to be functioning properly. Do I have a junk battery? It's new two years ago but a cheap battery. Is something pulling while the key is off?

Any insight on solutions or tests would be great. Need to get it ironed out before the really nice wether hits. Can't be pulling the battery every night...

Stev-o · « **Reply #1 on:** March 11, 2012, 11:16:41 AM »

How many volts was the battery when installed? (should be 12+).
And now? If low, charge it again and check (you don't née d to pull it). Do you have a low amp charger? If not, you may have cooked it.
Then, when the bike is up and running, check voltage on battery at idle and at 4K RPM. At 4K voltage should be rising if it is charging.
Also check all connections. Good luck and let us know.

GrandRapids750K3 · « **Reply #2 on:** March 11, 2012, 11:26:58 AM »

It was 13.2 whe put in and 8.7 when I pulled it out. I believe my charger is a low volt charger. I've had to charger it a few times and it's always back at 13.2ish. When I get it back in the bike and get it to 4K what should the volts get up to? Thanks for the tip.

Stev-o · « **Reply #3 on:** March 11, 2012, 03:12:41 PM »

Quote from: GrandRapids750K3 on March 11, 2012, 11:26:58 AM

When I get it back in the bike and get it to 4K what should the volts get up to? Thanks for the tip.

You should see the voltage rise, that shows the system is charging. I have a feeling your battery is bad, buy a good replacement.

GrandRapids750K3 · « **Reply #4 on:** March 11, 2012, 04:41:56 PM »

So I gave it a full charged and checked it just ow you said. Battery went in at 13.2ish and showed no increase from idle to 4K. Went for a half hour ride that was frequently over 4K and when I checked it after the ride it was down to 11.4. Checked it an hour later, not running, and it was 12.3. Now that I think about it I should have checked the last time running...

If it is a charging issue what am I looking at replacing? Much more educated than I was a year ago on the electrical systems, but relatively speaking I have no clue. Thanks again for the help by the time all the gremlins are out of here I should be an expert....

bollingball · « **Reply #5 on:** March 11, 2012, 05:09:38 PM »

read through this.

http://forums.sohc4.net/index.php?topic=1012.0

Ken

GrandRapids750K3 · « **Reply #6 on:** March 11, 2012, 06:07:56 PM »

Thanks ken. I have been trying to read through as much info as I can in past threads. Seems like you can read as much as you want on the topic and somethings don't sink in, extra thick head I guess.... Exactly why I love being able to post stupid simple questions on the site, exactly why online education will never replace the value of an actual teacher in the class room...

I agree with you on the battery. Having just gone through all the wiring last summer I'm pretty sure all the connections are good. My hope is that it is just a component replacement to put this all behind me so that I can move to some of the mechanical tweaking...

scottly · « **Reply #7 on:** March 11, 2012, 07:07:48 PM »

First thing I would do is check the voltage on the black regulator lead, with the ignition switch on, and the motor not running. It should be within .5 volts or so of the battery voltage. Next, check the voltage on the white regulator lead; it should be the same as what is measured on the black lead. If it is significantly less than the black lead, it indicates a problem with the regulator.

CycleRanger · « **Reply #8 on:** March 11, 2012, 07:21:26 PM »

Test the diodes in your rectifier with a multimeter.
The shop manual has instructions.
You may have a bad diode.

Here's one thread about testing the rectifier.
http://forums.sohc4.net/index.php?topic=79731.0
There are others.

Spanner 1 · « **Reply #9 on:** March 11, 2012, 07:26:21 PM »

Lots of good advise so far.... if you rev. the bike and the voltage across the battery does not rise, the very first thing to do IMO is to separate the 8-way plug behind the airbox. This connector sends power to the field coil and carries charging power back from the alternator... very common to have overheated/blackened/ dirty connections here... also one or more of the 'spades' may 'back out' of the connector when plugged back together. Take a close look and shine up all the 7 spades and make sure all 7 wires make a solid connection with their mates when the halves are plugged together......I look at his connector before every long ride, it and the rectifier plug !.... good luck.

grasscutter · « **Reply #10 on:** March 11, 2012, 08:02:13 PM »

To OP: Your scenario just happened to me 2 weeks ago.
Batt. was just dry. Topped off with distilled H2O. Overnight charge.
All is good. Starts every morning, charging system A-OK!

let's hope your solution is simple as well.

TwoTired · « **Reply #11 on:** March 11, 2012, 10:16:33 PM »

It can be frustrating to check a charging system without a known good battery, as a bad battery can make the charging system look faulty.

Charge the battery fully. The remove from charger and let it rest for 2 hours unconnected before measuring its voltage. It should be 12.6-12.8V in this condition.

Then start the engine (kick start is best here), and make a voltage chart showing the voltage reading at idle, 2000, 3000, 4000, and 5000 RPMs.

If you deplete the battery with electric start before hand, hold at 3000-4000 RPM for 15-30 seconds an watch the battery voltage change trends. The bike's charging system does not replenish a depleted batter quickly. In fact, it would take 10-ish hours above 3000 RPM to fully charge it from depleted.

If the charging system is weak, like a bad diode in the rectifier, or a bad leg of the yellow wire connections, removing the headlight fuse, will help charge a battery to peak.

GrandRapids750K3 · « **Reply #12 on:** March 13, 2012, 05:45:39 PM »

So a quick update. I don't have a multimeter unfortunately so I was not able to do all the tests suggested, I'll have to go pick one up soon. I also have not got a chance to check the 8 way plug either... These 12 hour days at work are killing me... I did get a chance this afternoon to run out and just see if it would start after sitting for a couple of days and it fired right up. Battery read 12.1 when not started and 11.3 when running. Revved the engine up to 4000 a few times and voltage did not change a bit. This makes me think it's not the battery and possibly the rectifier? Am I jumping to conclusions? If I get a chance to take it out for a longer ride and I come back and the battery is low would that indicate a rectifier issue? And how lng of a ride do you think it would take to drain it down?

Thanks again for the tips and I'm going to try to get my hands on a multimeter some how....

Spanner 1 · « **Reply #13 on:** March 13, 2012, 08:18:48 PM »

Don't take your bike on a ride, it's not charging and you will have to push it several miles home

need to do the things suggested by responders to your questions..... and report back.

Stev-o · « **Reply #14 on:** March 13, 2012, 08:28:08 PM »

GR - get a multimeter! What are you using?
They are not expensive, I'm sure you can afford 20 bucks...

http://www.google.com/products/catalog?q=Multimeter&hl=en&um=1&ie=UTF-8&tbm=shop&cid=17727707544216750142&sa=X&ei=nw9gT7rLFOaGsgL-vtz_Bw&ved=0CJ0BEPMCMAE

phil71 · « **Reply #15 on:** March 13, 2012, 09:22:05 PM »

even if the battery's shot, you should see a rise in volts when the rpm comes up. I'm betting on the regulator...

TwoTired · « **Reply #16 on:** March 13, 2012, 10:23:47 PM »

A single broken wire/connection to or from the Vreg can stop the charging system from working.

Either buy test tools to help you locate the fault, or replace the charging system piece by piece until it works again.

Your call.

bollingball · « **Reply #17 on:** March 14, 2012, 09:35:15 AM »

Quote from: GrandRapids750K3 on March 13, 2012, 05:45:39 PM

So a quick update. I don't have a multimeter unfortunately so I was not able to do all the tests suggested, I'll have to go pick one up soon. I also have not got a chance to check the 8 way plug either... These 12 hour days at work are killing me... I did get a chance this afternoon to run out and just see if it would start after sitting for a couple of days and it fired right up. Battery read 12.1 when not started and 11.3 when running. Revved the engine up to 4000 a few times and voltage did not change a bit. This makes me think it's not the battery and possibly the rectifier? Am I jumping to conclusions? If I get a chance to take it out for a longer ride and I come back and the battery is low would that indicate a rectifier issue? And how lng of a ride do you think it would take to drain it down?

Thanks again for the tips and I'm going to try to get my hands on a multimeter some how....

You say in this post that you don't have a meter so how are you getting the voltage reading of 12.1 and 11.1

Ken

GrandRapids750K3 · « **Reply #18 on:** March 14, 2012, 05:13:13 PM »

Battery charger has a meter function. Got a buddy who's ging to bring one by some night to get to the bottom of it all....

GrandRapids750K3 · « **Reply #19 on:** March 15, 2012, 08:31:47 AM »

Ruled out the regulator. Black and white are within .5 and right around the same voltage as battery (thanks scottly for the clear directions).

Been doing some reading on the threads about testing the rectifier and will try to get some tests done on that soon...

In the mean time, if my battery does need some distilled water how full do I fill?

phil71 · « **Reply #20 on:** March 15, 2012, 09:33:26 AM »

don't dilute your battery electrolyte with distilled water. That's okay in a car, but if it were me, I'd go to Auto Zone and ask for jug of battery electrolyte. It's cheap, and it'll come in handy for a long time.

strynboen · « **Reply #21 on:** March 15, 2012, 10:38:16 AM »

dest vater are ok..dont fill any other stuff on..the only thing who dissapeares from the battery, are dest vater..so refill vith dest vater

battery are prinsipial same in boats cars and mc..

TwoTired · « **Reply #22 on:** March 15, 2012, 12:05:55 PM »

Quote from: phil71 on March 15, 2012, 09:33:26 AM

don't dilute your battery electrolyte with distilled water. That's okay in a car, but if it were me, I'd go to Auto Zone and ask for jug of battery electrolyte. It's cheap, and it'll come in handy for a long time.

I must protest this bad advice.
Battery acid is H2SO4. What leaves the battery is H2O when the H2SO4 breaks down, leaving SO3 still inside the the battery. To reconstitute, you add H20 (distilled water) to restore the electrolyte level and have the SO3 recombine with the H2O. (Basic and crude explanation. Wiki has better chemical equations for the budding chemists out there).

DO NOT add more electrolyte (H2SO4). That will result in acid much too strong in strength and will literally eat the internal plates away far more rapidly.

Lots of people post complaints of short battery life. Restoring lost fluid level with electrolyte instead of Distilled water is a sure way to accomplish that.
The exception is if the battery was turned upside down and drained of electrolyte, rather than chemically converted, for fluid volume loss. Only then is it proper to restore with electrolyte instead of pure water.

Cheers,

GrandRapids750K3 · « **Reply #23 on:** March 15, 2012, 01:20:55 PM »

Thanks TooTired. I've always heard distiled water is the way to go and it's hard to argue with you're explanation. Am I topping it off? I looked at my battery and some are about half an inch from the top and a couple are about an inch from the top. Is this low and if so how low?

TwoTired · « **Reply #24 on:** March 15, 2012, 01:28:12 PM »

I've yet to see a lead acid battery that didn't have a fill line marked on it.

On the 550 it is easily seen from the side. For the 750, maybe you have to remove the battery to see those fill lines.

BTW, the volume changes with charge state. A depleted battery will show a lower fill level than a fully charged one. So, the fill line is a goal when the battery is fully charged. You need just enough electrolyte to immerse the plates internally for charging. Then after full charge, bring the level up to the fill line on the battery.

Cheers,

GrandRapids750K3 · « **Reply #25 on:** March 15, 2012, 01:56:48 PM »

I got it on the charger since this afternoon, I'll hake a closer look for a fill line and go from there. Thanks again.

phil71 · « **Reply #26 on:** March 15, 2012, 05:34:26 PM »

Huh.. I'll keep that in mind. I can say I've gotten 5 seasons out of batteries topping off with electrolyte, regardless of the underlying chemistry.

GrandRapids750K3 · « **Reply #27 on:** April 15, 2012, 07:11:32 PM »

Old rectifier was trash. Ground wire must have shorted out at some point and was then ripped off. For piece of mind I just ordered a replacement from Oregon Motorcycle Parts. Can't wait to plug it in and see what happens!

bollingball · « **Reply #28 on:** April 16, 2012, 04:45:09 AM »

Quote from: phil71 on March 15, 2012, 05:34:26 PM

Huh.. I'll keep that in mind. I can say I've gotten 5 seasons out of batteries topping off with electrolyte, regardless of the underlying chemistry.

I must go with TT on this. Never anything but distilled water unless turned over like he said. I wonder if you could get more life out of one if you shook it real hard and drain it flush it a couple of times then fill it with new electrolyte. I have never done it but may try it it on a old battery I have just to see what happens.

Just think if you had done it correctly you may have gotten 7 or 8 seasons.

Ken

CycleRanger · « **Reply #29 on:** April 16, 2012, 07:23:55 AM »

Quote from: GrandRapids750K3 on April 15, 2012, 07:11:32 PM

Old rectifier was trash. Ground wire must have shorted out at some point and was then ripped off.

Ah ha! I was right!

GrandRapids750K3 · « **Reply #30 on:** April 16, 2012, 09:15:10 AM »

I do love when someone was right, makes life easier for me. Now I just hope my new one does not succumb to the fate of the last one. Hopefully the rewire that was done will take care of that... It's already in the mail so I'm looking forward to it....

Spanner 1 · « **Reply #31 on:** April 16, 2012, 10:00:13 AM »

FYI, OP........... the main causes of a rectifier being shorted-out and wires 'burnt' are external factors....
Either someone connected a battery charger or tried to 'jump' the bike from a car battery with the polarity reversed or bike battery was connected to an auto type 10 or 20 A charger ( correctly ! ). If you find yourself stuck with a flat battery and only a car type charger at hand, set it on it's lowest charge rate and UNPLUG the rectifier before attaching the chargers leads

GrandRapids750K3 · « **Reply #32 on:** April 18, 2012, 05:02:05 PM »

Bolted on and plugged in the new rectifier this afternoon and it looks like things are good to go... Tested with the multimeter and once I hit that throttle the volts jumped from 12.5 to 14.4ish range... Finally getting some juice back to the battery! Can't wait to actually get out and put some miles on to test it out... Also brought my new daughter home from the NICU today, so not sure when I'll get to put those miles on; good day today....

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Author Topic: Battery/charging issue (Read 6251 times)

bollingball

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