Overcharging the battery, maybe ... ???

nobradovic

Can someone help me with some suggestions. I had charging problems. I have been changed my original voltage regulator, because i suspected it was faulty. I used car voltage regulator which triggers on 14.5V. I re winded my stator by a specialist, and put new diodes too. I found that charging seems to "works" perfect. I had 14.5 V on 2500 revs. Everything looks great, but after few days, my battery was dead. I found some electrolyte missing. The battery was brand new. I don't suspect diodes and stator. Stator was re winded to the original specifications, and diodes work OK. I think that regulator is one to blame. Because it is designed for a car (45-55 Ah battery, I supposed. There is no mark on it, just 14.5V mark), i think it overcharges my battery with stronger current, then original one. It is logical, isn't it?

I think the charging current is stronger on car's regulator, then on bike's one. (45-55 Ah battery VS 14 Ah battery) For bikes, it should be near 1Ah, during charging. Isn't it? I don't now how strong my charging current is. Is it possible, that stronger current kills my battery? I think that low electrolyte level, after few days of riding, can be a sign of overcharging battery. PLEASE HELP !!!
If You have some questions, please ask !!!

Yamaha XS650 Special, Year '79
Boyer's ignition
Dell Orto carbs

Nikolas

jayel

might ask here...
xs650temp.proboards29....d=Charging

some pretty bright guys over there, might be able to steer you in the right direction

pumps

You think it's boiling the electrolyte out? I know this is a long shot but no chance of a battery leak? Like a crack maybe? No sign of leakage.
By the way you write very good english.

pamcopete

The voltage regulator is a .....voltage regulator. Whether on a car or a motorcycle, it regulates the voltage, not the current. On both cars and motorcycles, the alternator is built to produce enough current to run all of the electrical equipment and charge the battery with whatever current is left over. The battery is sized to be able to absorb this surplus current, so there is a bigger battery (greater Amp Hour capacity) in a car with, say, a 60 amp alternator. In the case of the XS650, the full load of the electrical system is about 12 Amps with everything on. The alternator produces 16 Amps at 5,000 RPM, so at any less RPM's, it will produce less. Probably in the order of 14 Amps during cruise, which leaves about 2 amps to charge the battery. The battery is a 14 Amp Hour battery which should be charged at a rate of 1.4 Amps, but that is when the battery is not already charged, so it will draw less once it is charged.

So, if all is working well, you will not overcharge the battery. The size of the battery is matched properly with the alternator.

However, if the voltage regulator is not working properly, and is causing the alternator to produce a higher voltage than 14.5, that will cause more current to flow into the battery and the result could be a loss of water in the cells.

So, you need to measure the battery voltage at a higher RPM (3,000 to 5,000) to see if the regulator is working properly. That can be a problem with the bike not moving due to a tendency to walk away on the center stand and overheat, so you should rig a voltmeter somehow (Velcro on the tank?) so you can see the battery voltage at the higher RPM's while riding. Even at lower RPMs, you should wait a couple of minutes for the battery to regain its charge after starting before you take a reading.

Retiredgentleman

nobradovic; It would appear to me that your charging system is working correctly.

The next thing that occurs to me, is you may have a constant small load that is drawing current when the bike is just sitting. Do you have any accessories wired directly to the battery i.e. extra lights etc. ?

Remove the main 20 amp fuse. Leave the ignition key off. Connect your multi-meter to the terminals of the main fuse selected to read amps on the 10 amp scale. If you read less than 200 ma, you could switch the meter to read on the 200 ma scale. There should be no current reading on this test.

nobradovic

Thanks ALL of You on quick response.
Now, after Pamcopete's comment, I think, I understand the function of VR much better. So the alternator output is responsible for the current (how much Amps), not VR. If I understood well, VR regulates just voltage, isn't it? I told You that I re winded alternator, because it was faulty. Maybe, I should suspect alternator output ??? I checked, if I have some current drain, and I found nothing. (with Ampermeter on mA). There is no cracks or whatsoever on the battery. So there are two possibilities:

1) Charging system does not have enough power to charge battery well. Maybe bad re winded alternator ? Not enough Amps ?

2) Charging system overloads the battery somehow, and I don't know how?

aybe low electrolyte level is result of low alternator output, or bad charging ? Should I suspect diodes? And whats with rotor? I passed all checking posted on this site, regards charging problems, but I didn't find anything helpful for my case?

Can someone tell me the diagnostic procedure for such problem. Thanks in advance.

Nikolas.

PS. Thank You Pumps !!! :--))

pamcopete

nobradovic

Well, even if the alternator was producing more than a stock alternator, it couldn't be that much more because there is only so much space for the wire. And, when the battery is fully charged, it will not draw any more current, even if more current was available, so we are back to the possibility that perhaps the voltage regulator is causing the alternator to produce a higher voltage, so try as I suggested and measure the battery voltage at 3,000 to 5,000 RPM.

pumps

Pete I'm picturing my self on my 77 riding down the street at 3-5000 rpms with my Fluke strapped to the tank trying to look at the volts! LOL

pamcopete

pumps,

Well, yeah.....but you don't have to be in fifth gear going 80 MPH LOL.

I have a digital voltmeter installed permanently in my '81/H, so I guess I was thinking of that when I made the suggestion.

pumps

I'm sure I look funny PERIOD without my meter!!! A voltmeter is on my list...tomorrow should get your ignition kit and coil + wires arriving from mikes..I'm stoked and the weather will be in the 50s here but I have to pull a 24 hr shift! Waaaaaaa!!!! Just have to wait I guess.

Retiredgentleman

nobradovic; There is a method to check if your alternator is charging your battery.

Remove the main 20 amp fuse. Select the 10 amp scale and make sure your meter leads are plugged into the VOM meter in the 10 amp terminals.Now connect the meter leads to the 2 terminals of the main 20 amp fuse holder.

Perform a small polarity test by turning on the ignition key. You want an analog meter to have the needle go below "0" (read backwards). You want a digital meter to read with a "negative sign". Reverse leads as required to achieve this. Your meter is now set to read current flow INTO the battery. Turn off the ignition key.

Now start your engine as you normally do and watch the currrent reading on the VOM. It will take a few minutes before the battery recovers from starting. At idle 1200 RPM there will be no current flow into the battery. As you increase the RPM to 2000 and 2500 RPM you should see the current flow increase to 1.8 to 2.0 amps. If this occurs then all is well with the alternator and charging.

jerseyjew · Full Member Joined: Mar 28, 2008 Posts: 48

Retired,
Is there a diagram of this process anywhere? My bike was completely rewired by the previous owner, so I need some help figuring it out! Thanks
- Joe

jayel

like this

nobradovic

Dear friends,

Thank You All again !!! I will try everything you suggest me. My bike is now in state of "winter hibernation", because of the snow. I wants to be prepared for incoming season, cause my charging system doesn't work properly. I tried, what I told You, and it was a "dead-end street".

I didn't try to measure amps, like mr. Retiredgentleman told me, and didn't try to measure voltage when bike is on the run, on 3000-5000 rpm like mr. Pamcopete told me.
So, I have lack of input, I guess. I will measure this as soon as possible. I'm gonna try to find if I have some current drain again, because it seems, it is plausible too.

Can someone tell me what if my stator is not re winded well, and I don't have enough amps of AC current (before diodes). How can I measure this ?
I will be happy, if I can localize the problem on exact device such as stator, rotor, diodes or voltage regulator. As I told you before, I have 14,5V on 2500-3000 rpm, measured on idle. If I turn my lights on, it's brighter on higher rpm. So I have some charging, but anyway, after few days, the battery is DEAD !!! When I recharge the battery, the same problem occurred again, and again. My first suspect was current drain, but I didn't find anything. After that I suspect on alternator output, and voltage regulator. Each of these parts works, but maybe not correctly and in correct limits, and problems like these makes a lot of headache.

I tried everything I knew, so I need some "brainstorming" with You dear friends, to catch some ideas before I go to my garage again.

THANK YOU EVERYONE !!!

Buddy78SX650

I don't have any answers to your questions but I wanted to tell you that is a very nice looking bike, I really like the yellow and black.

jayel

nobradovic it does sound like a current drain, the only way it can drain with the key off is thru the voltage rectifier next time you charge the battery unplug the recitifer (under battery box) and see what the battery does if it still discharges it may just be a bad battery

Retiredgentleman

jerseyjew;
The diagram should help you to connect up for the test. Thanks jayel for making the diagram.

There's really only 3 possibilities.
1) Alternator/Charging system is not putting out enough current................use the method that goes with the diagram to test for current flow into the battery.

2) Constant current drain with key off............the first test I mentioned should detect that problem. Any extra loads wired direct to the battery will cause same problem.

3) Battery is defective.

nobradovic · yamaha final (21.11.2008) 014.jpg

Thanks guys. I appreciate all advices very much.
I will check all suggested tests as soon as possible, and inform you about results.
In a meanwhile, any new idea will be welcomed.

PS. Thanks, Buddy78SX650

Some more pics...

nj1639

Very nice! I like the low seat.

HndaTch627

sorry to bump an old thread but i noticed that he's running a Voltage Regulator from a car, I suspect there is a short in my VR causing it to drain my battery(bike previously had no parasitic draw problems but after 50 miles of riding and the bike sitting for 4 days the battery was dead). What vehicle regulator would be easy to wire in? I was thinking something off a Ford would probably do the trick. Has anyone gone to a different voltage regulator other then the Yamaha unit?

Retiredgentleman

Tons of information for use of automotive regulators. There are 2 classifications, depending if your bike is 70 to 79, or is 80 to 83. Just
pick the correct link and starting reading.

xs650temp.proboards29....hread=3246

HndaTch627

well nevermind my last post, my rotor is internally shorted. Are there any options other then purchasing a new rotor from MikesXS?

an this sucks, finally got to ride the bike and this thing nukes itself. Dammit.

pumps

I think customrewind.com/ can help you too.

HndaTch627

so the rotor problem seems to be fairly common but how common is it for the stator to fail? it looks like their may have been moisture inside the cover at one point in time but the field coils check okay. I'd rather not dump $200 on a stator if they are pretty solid.

Jeremy

What Happened to 650rider.com?

Yamaha xs650