How much cranking should a battery give?

The question is: "How long should a good battery be able to crank the starter?"

Now, I did search, and I found a similar post from a ways back. Someone else had the same question, and at least one person suggested that over ten seconds at a time, several times, could be expected. But that seems like a lot.

Background: Bike is a '92 750F. I bought it a couple years ago with 32k miles on it. Never had any electrical problems.

Scenario: I stopped at a light. When the light turned green, I reached for the throttle. Bike died. There was a car behind me, so I instinctively hit the start button and cranked it a few times. Nothing. That's when I finally noticed that the ignition cutoff switch is off. I must have hit it when I reached for the throttle. Oopsie. So I put it back in run, hit the start, and get nothing. The battery died that quick! Well, I eventually got a jump start, and brought it home.

By the time I got it home (a 2 mile ride), the battery voltage measured 12.8V. I flipped the cutoff switch and cranked it. It turned over HARD! But after 5 seconds of cranking, battery was dead again. Dead voltage : 12.6V.
I brought it inside and charged it. (Well, topped it off, anyway. Since 12.6 isn't very dead.) I carefully cleaned all the terminal contacts. I tested the voltage under a modest load of 2 amps, and the voltage read 12.3V under that load. Then I put it back in and tried it again. Same thing. Cranks great for about 5 seconds. Well, maybe 8 seconds.

The voltage with the motor running is 14.6V. This seems a tad high to me. Whether idling or revving, it is rock steady. Well, for the short time I actively measured it. There are no signs of burned wires anywhere I can see, but I admit I don't know how to find the voltage regulator... yet.

There was a decent amount of blue crud on the positive terminal, which is consistent with a slight bit of overcharge.

Hindsight: my first VFR also did the same thing. But since 5 seconds of turnover is typically 10 times as much as I ever need (as long as the cutoff switch is in the "run" position, at least!), I never really worried about it, before.

Any thoughts, suggestions, or opinions appreciated.

 

Good question boss.

For reference… Ghosts battery guide link.

Ghost says lets learn about Batteries

direct answer for your question is not gonna happen. You can buy a battery that “says” 4500 CCA on it. However, your battery is undergoing tremendous stresses we simply can not account for…. This 4500 CCA is a lab tested rating. Any sales guy that argues a point of “I guarantee a minimum of 4500 CCA” is a flat out liar.

Your numbers seem ok. But you got one missing. AMPS. The battery’s voltage tells only half the story here. You could see good voltage, (as yours does), but there could be a short in one of the cells, which under a load draw, the AMPS bridge over, and you loose your “power” to turn over the starter motor effectively.

Several key things you said there got me thinking you may contributed to your situation.

Water level. Ya got to keep on top of this at all times, if you are to keep a wet cell battery going as long as you can. IMPORTANT IMPORTANT IMPORTANT

“Blue crud”. This is Lead Sulfuric Oxide. It means your battery is sitting more than its being used. Once the oxidizing starts, you must clean it off immediately. Oxidized terminals decay at a rate much faster than a stagnant battery. FYI, the blue or yellow crud, is a 100% clear indication that the battery is about to go bad.

Short rides. Refer to the link again, however note; short rides will wear out a battery and R/R a lot faster than long rides.

Few start attempts in off position. Fuel soak. More than likely your battery wouldn’t be an issue in this instance, (assuming your battery is top notch, which its not).. you got too much fuel in your engine at this time.

You charged your battery, and the charge isn’t holding. Sorry bro. battery is bogus. Its not a battery if it cant hold a charge properly.

**Let me be very clear here**
Batteries do NOT have to show low voltage to be bad. Matter of fact. About 50% of bad batteries show a full Voltage.
****

Now lemme answer your question best I can.
How long should you “attempt” to crank your engine?
~ 2 seconds.
What if it doesn’t even try?
Choke, or fuel isn’t right… sorry.
What if its an old engine, (20 yrs old)?
~2 to 5 seconds MAX.
Why do you pause after 5 seconds?
To let the heat build up in the chamber, and the gasoline fumes rise, so when you respark it may ignite better.
So, nothing to do with a good battery?
Nope! (a GOOD battery)
What voltage is considered min to start a motorcycle, given it’s a good battery?
~11.4V min.
Whats the max?
~16V (your battery wont take any more, its impossible. Though, note, constantly overcharging your battery, is the same as undercharging it… makes it weak and reduces the life)
What is the running (with AC generator going), voltage?
~13.2V to 16V
If you take care of a battery, as if it were a potential BOMB, how long could it last?
Typical battery could last ~3 yrs if properly maintained.

Dude, your battery is bogus. Go get a new one.

 

Bad battery. Mine did the same on Thursday. Died at the gas station. The voltage and amps go low and there's not enough voltage,while cranking, to let the ignition box's fire properly. Not a real problem, I just took about 6 running steps and bump started it. Fired right up. You may want to learn that.

 

Thanks for the suggestions.

I ordered a new battery. But I'm also considering changing my kill switch out for a temporary push-to-break switch.

I figure the way I ride it (sporadic with a lot of short rides) my new battery probably won't last all that long.

 

Discovered something new

So after getting my new battery, I looked closer at the old battery.

The sticker said "sealed battery. Never add water. Do not open."

So I opened it. 4 of the cells looked bone dry. I think this "sealed" battery must have leaked last year when I had my accident. Just adding some distilled water brought the battery back up to quite serviceable.

Funny thing was the very next day after I got my battery, I decided to run to the store and back, before changing it out. I stopped for gas. My battery died. lol. So I tried to bump start it. Put it in second gear. Took 6 running steps. Dropped the clutch.... rear tire just slips and then the bike stops. Tried it again. Same result. Finally got a guy to push it for me while I was sitting on it and it worked.

So when you bump start it, do you jump onto the bike like a cowboy before dropping the clutch? I don't think I'm that athletically capable.