More Battery/Charging Issues!

[Guest]

Little Background:

Went for a 25 mile ride Tuesday, and the bike stalled when coming to a stop off of high revs a couple of times. Toward the end of my trip, it stalled and wouldn't start again. I could feel the battery draining, so instead of cranking and cranking and cranking, I popped the clutch in second and she started right up.

So I decided to test my battery. I didn't charge it first, so keep that in mind.

With my multimeter set to 20v, I got:

Off:12.68v

Lights on: 12.03v
Idle: 13.40 - 13.50v
2500 rpms: 13.40 - 13.45v
5000rpms: It was steadily climbing, starting at 13.40v and it made it up to 13.65v then settled immediately down to 13.30v.

Because it looked like the battery was charging up while running, I decided to try it again, so I did and got readings of -

2500rpms: 13.75 - 13.90v, finally settling at 14.00v
5000rpms: 13.45v

Now here's the problem:

Hadn't gotten a chance to do anything more to it since Tues., not even fully charge the battery. Went out this morning to do just that, and the thing was dead. Tested the battery, and I got 1.8v. Not enough to even light the dash.

However, when I hooked it up to the charger, it registered the battery as "charged" and I tested it still hooked up to the charger and got a reading of 13.65v

I took it off the charger and tested it and got a reading of 7.6v which steadily fell down to 7.3v when I stopped checking and hooked it back up to the charger, where it still registered the battery as "charged" rather than
"charging."

When it's hooked up to the charger, and I turn the key, the lights and everything come on, and the charger then registers the battery as "charging" but as soon as I turn the ignition to off, it goes back to registering as "charged."

So? What have I done wrong and what do I need to do?

Thanks, guys.

Mike

[DaveT.]

If your battery falls below 9VDC anytime, it's toast in my opinion. Get a new battery. Probably take out the stator with that battery... :shock:

Either that or check for a drain with the ignition off. Use the ammeter between the neg batt cable and the neg batt terminal. Less than 250mA DC would be best.

[qslim]

DaveT hit it on the head. Sounds like your battery bought the farm. Charging numbers seem okay, that's about what I get on my 850. Grab a new one and go with the current draw test to make sure nothing on your bike is sucking juice while it rests.

[UncleMike]

So, what caused this so suddenly? Is there something I did?

Just tell me what it is I'm doing that it doesn't like and I'll change! I swear!

Nothin' like getting the "It's not you, it's me" speech from your charging system.

[UncleMike]

Probably take out the stator with that battery...

Does it sound like it's bad, or is this more as a preventative measure?

Either that or check for a drain with the ignition off. Use the ammeter between the neg batt cable and the neg batt terminal. Less than 250mA DC would be best.

I'm an idiot, so could you walk me through this? I've got a multimeter. What should I set it to, and where should I put each end? (Symbols in regards to AC/DC/Amps etc., are always helpful.)

Thanks,

Mike

[dietcokeking]

So, what caused this so suddenly? Is there something I did?

It's not unusual for a battery to fail suddenly.

[UncleMike]

It's not unusual for a battery to fail suddenly.

How come this has never happened with any of my cars? It seems if this only happens with bikes, or only happens with older vehicles, that there would be a cause. And if there's a cause, it's something that can be identified, and subsequently prevented or eliminated.

[earlfor]

Your charging system numbers are right on the money. They are identical to my numbers on the 1150. Your battery however, is of use only as an art object or paperweight. Its done for, replace it. Very roughly speaking, the battery charger senses voltage, electrical pressure, as to when to cut off or register a full charge. As a battery sulfates, internal resistance increases and it takes more voltage to "shove" a charge into it. Or, the same applied charging voltage results in less of a charge in the battery. (however you wish to think about it) Once sulfation/particles settle and reach the bottom of the plates, the cells ground out and you have a battery that is what we call "dead". So the short form is that resistance is increased, it takes more voltage to overcome the resistance and that pressure level is sensed by the charger as the battery being fully charged. (yes, I know this is not technically precise. Its meant as a short explanation of why the charger says fully charged and the battery is dead.) :-)


Earl

How come this has never happened with any of my cars? It seems if this only happens with bikes, or only happens with older vehicles, that there would be a cause. And if there's a cause, it's something that can be identified, and subsequently prevented or eliminated.

[dietcokeking]

How come this has never happened with any of my cars? It seems if this only happens with bikes, or only happens with older vehicles...

I've had it happen once about 10 years ago. It was the five-year-old OEM battery in my car. It was fine on the morning of a fine summer day, but wouldn't crank the warm engine in the afternoon. I replaced the battery, and had no more problems. I learned that sudden failures are more common in hot weather. How common the problem I can't say, but I'm told when the sulfate reaches the right place, the battery is toast.

[Mike McNaney]

Yep. The battery is shorted internally. This is how batteries typicaly die. Seems it only happens in old cars because they are old. The system overcharges the battery (14.0v) constantly throughout its life and this creates a corrosion inside the battery. Over time the corrosion on each plate gets bigger and bigger until it touches the corrosion of the plate next to it. The corrosion is not solid but is still a ground between plates. Time and overcharging make these grounds denser until the battery wont pass voltage either in or out.
Bike batteries do this more because of their size and that motorcycle battery technology is still in the 70s'. They do have maintenance free bike batteries now.

[UncleMike]

Wonderful. Thanks Earl, and everyone else.

Originally Posted by DaveT.
Either that or check for a drain with the ignition off. Use the ammeter between the neg batt cable and the neg batt terminal. Less than 250mA DC would be best.


I'm an idiot, so could you walk me through this? I've got a multimeter. What should I set it to, and where should I put each end? (Symbols in regards to AC/DC/Amps etc., are always helpful.)

Any chance on elaboration here? Am I putting the ends of my multimeter on the neg battery terminal and the negative battery cable? What should it be set at?

Thanks,
Mike

[Ridealot]

Sounds like the typical Yuasa sudden battery failure. Since motorcycle batteries are smaller than a car battery the plates inside are closer together. Combine that with the more hostile environment a bike battery lives in (much more vibration than a car) and the plates in the battery break free. Once 2 plates touch inside the battery its all over. Sudden battery death. Time for a new battery.

[UncleMike]

So, just venturing into theoretical territory here, and rest assured that I would never try this and am getting a new battery;

BUT

Theoretically, couldn't you open this up and clean off the plates and be good to go, assuming you had more acid and distilled water to replace the old stuff? Again, I'm not going to do this, attempt this, or even take my battery apart, but I'm just thinking about stuck in the outback/after the apocalypse solutions. Call it a burning desire to KNOW.

Also, this should happen less often if I get one of those sealed/maintenence free batteries, correct?

[RobGS850L]

I've done the old shake up the battery to get the junk out and drain it and refill it with new acid and that would work for about a week sometimes longer. Best thing is to go get one of the gel filled batteries and worry no more.

[Mike McNaney]

Thats a theory that should stay in the box. An automotive battery can kill you in more ways than one. By opening one up, you've got the devil on both shoulders.