Topic: Did I kill the battery?

[old750]

I forgot my key in the ignition, in the on position, with the lights on, for about 30 days. Lucky it didn't get stolen from the underground parking lot. So I tried and tried to kick start, jump start, yelling start, and nothing. I bought a battery charger and it just reads way over 100% charged whether I flick it 2Ah or 10Ah. I don't understand the dials so I just left it on 2Ah for a couple hours. I turn the key to on, then turned it past the on (forget what that is called - park?) and the running lights in the back light up. But nothing else. My starter is dead (or the solenoid?) so I tried kick starting jump starting with no luck.

Now I've read that I may have damaged the rectifier. This sucks. Have I totally killed the battery to the point of no return?

[TwoTired]

Your bike will never start without battery juice "priming" the alternator and spinning at about 2000 RPM.  Even screaming won't make it spin this fast.
The coils won't spark the plugs without battery power.

30 days is a long time to have a battery be totally flat.  The battery plates may be sulfated and unable to accept or provide current.  Jump starting the bike should work though, if you meticulously maintain proper polarity, your charging system should survive.  You're going to have to have a fully charged battery to check that out.

Sometimes a flattened battery can spring back if given a good long charge interval.  Don't leave it in the 10A charge position. If it does start accepting a charge it'll overheat rather quickly and get ruined if you don't catch it quickly.  A smart charger won't charge a battery with no voltage.  You will need a dumb 2A non-sensing charger to hold a potential on it for an extended period of time.  Or, another good battery connected in parrallel for any hope of reactivation.

In the end, you may just need to replace the battery, anyway.

Cheers,

[old750]

Jump starting the bike should work though, if you meticulously maintain proper polarity, your charging system should survive.

Hey thanks for the thorough response. Much appreciated. What do you mean by maintaining polarity?

[Blaize]

He just means be carefull not to hook up the jumpstart/charger backwards and make a bad thing worse.

[TwoTired]

Hey thanks for the thorough response. Much appreciated. What do you mean by maintaining polarity?

Always connect the positive cables to the positive terminals and negative to negative.  If you reverse this connection, even momentarily, the charging system rectifier and wiring usually goes molten and emits smoke.  When you let the smoke out of electrical devices, they seldom work anymore.  Only the factory knows how to put the smoke inside those devices.

[old750]

When you let the smoke out of electrical devices, they seldom work anymore.  Only the factory knows how to put the smoke inside those devices.

That's a damn good way of explaining things.

[johnny-from-bel]

Lead accid batteries do not take deep discharge very well. If this is a one off, it probably will survive.
I happen to have good result with reving batteries by giving them an EDTA treatement and then fully charge en discharge them.

The cycle I apply is a full charge with max 1A until the battery tension is 13.5V, then discharge by hooking up a 21W lamp for 8 hours.
Repeat a few times (3, 4). And a completely dead battery is usuable again.

Ofcourse there is a limmit to howmany times you can do this trick

[old750]

i jump started off a forklift battery today at work just to see if it would work and sure enough it ran kept it above 4000 for a couple of minutes. i think i would have to go for a long ride to charge it now?

[pyro139]

i'll drum in on charging, your battery is a 12aper hour battery so a 2amp per hour charge you need charge for 6 hours not 2. 10amp is auto charger will chut on and off as bettery hits right charge and back on if power drops.

[Gordon]

i'll drum in on charging, your battery is a 12aper hour battery so a 2amp per hour charge you need charge for 6 hours not 2. 10amp is auto charger will chut on and off as bettery hits right charge and back on if power drops.

You don't want to use a 10 amp charger on a motorcycle battery unless you like replacing it often. 

[pyro139]

i'll drum in on charging, your battery is a 12aper hour battery so a 2amp per hour charge you need charge for 6 hours not 2. 10amp is auto charger will chut on and off as bettery hits right charge and back on if power drops.

You don't want to use a 10 amp charger on a motorcycle battery unless you like replacing it often. 

realy not even a auto tender unit?

[pyro139]

woops ya checked manual 10 amp is car battery 2 amp is tender woops, will using 10amp once destroy battery?

[Gordon]

woops ya checked manual 10 amp is car battery 2 amp is tender woops, will using 10amp once destroy battery?

Doubt it, but you don't want to do it very often.  The trickle charge on most car battery chargers is about the max charging rate you want to use on a motorcycle battery.  Lower is better. 

[pyro139]

woops ya checked manual 10 amp is car battery 2 amp is tender woops, will using 10amp once destroy battery?

Doubt it, but you don't want to do it very often.  The trickle charge on most car battery chargers is about the max charging rate you want to use on a motorcycle battery.  Lower is better. 

good only had the adjustable charger for a month only charged battery once at 10amp, use to use a 1amp trickle so 12 hours to charge, baught the 2/10amp adjustable for electrolosise.

[ofreen]

If you decide after all the dinking around that the battery is weak, you are better off getting a new one.  To keep them light, motorcycle charging systems are pretty light duty, especially on these old bikes.  They are intended to keep a healthy battery charged, not nurse-maid a crappy one.

[johnny-from-bel]

If you decide after all the dinking around that the battery is weak, you are better off getting a new one.  To keep them light, motorcycle charging systems are pretty light duty, especially on these old bikes.  They are intended to keep a healthy battery charged, not nurse-maid a crappy one.

According to specs, the 750 generator will pump out 13 Amps max. That is lighter than my car generator who will pump out 80 amps but not what I would concider light.

[TwoTired]

According to specs, the 750 generator will pump out 13 Amps max. That is lighter than my car generator who will pump out 80 amps but not what I would consider light.

Actually, specs. say both 12V 13A (156Watts) and elsewhere, 210 watts at 5000 RPM, if you use 12.8 as the reference voltage (like headlights are rated) then the alternator is capable of 16.4 amps. I suppose we could argue about peak duty vs continous duty.  However, the bike absorbs 10-11 amps or more to operate the stock electrical components.  It is only the excess power that is available for battery charging.  Um, weren't we talking about batteries?

I agree with ofreen.  Don't expect to drive a bike long enough to restore a fully depleted battery.  Unless you've got an endless ribbon of highway in mind.

Cheers,

[johnny-from-bel]

According to specs, the 750 generator will pump out 13 Amps max. That is lighter than my car generator who will pump out 80 amps but not what I would consider light.

Actually, specs. say both 12V 13A (156Watts) and elsewhere, 210 watts at 5000 RPM, if you use 12.8 as the reference voltage (like headlights are rated) then the alternator is capable of 16.4 amps. I suppose we could argue about peak duty vs continous duty.  However, the bike absorbs 10-11 amps or more to operate the stock electrical components.  It is only the excess power that is available for battery charging.  Um, weren't we talking about batteries?

I agree with ofreen.  Don't expect to drive a bike long enough to restore a fully depleted battery.  Unless you've got an endless ribbon of highway in mind.

Cheers,

I stand corrected. You need a hell of a ride to load it.

[333]

According to specs, the 750 generator will pump out 13 Amps max. That is lighter than my car generator who will pump out 80 amps but not what I would concider light.

It may be a bit late for this advice,but this is also why when you jump from a car, the car engine must be off.  It will pump that 80 ( alot of newer and larger approach 150) amps into your bikes charging system and fry, fry, fry.  Where as if the car is off, it'll only draw as much as it needs.

[johnny-from-bel]

According to specs, the 750 generator will pump out 13 Amps max. That is lighter than my car generator who will pump out 80 amps but not what I would concider light.

It may be a bit late for this advice,but this is also why when you jump from a car, the car engine must be off.  It will pump that 80 ( alot of newer and larger approach 150) amps into your bikes charging system and fry, fry, fry.  Where as if the car is off, it'll only draw as much as it needs.

Please look up Kirchoff's law on current conservation and you will see that this is an urban mith. Remember an alternator like a battery is a voltage generator not a current pump.

[TwoTired]

It may be a bit late for this advice,but this is also why when you jump from a car, the car engine must be off. It will pump that 80 ( alot of newer and larger approach 150) amps into your bikes charging system and fry, fry, fry. Where as if the car is off, it'll only draw as much as it needs.

I completely and totally agree with Johnny on this.

The Advice/Myth/theory provided about frying bike electricals with a car alternator, can be disproved with the bike's own electrical system.  The starter motor draws 150 amps from the bike's battery on start up.  If you have a charged battery in the bike, you have at least 150 AMP availability (and much more) from the MC battery.  And, the bike battery is directly connected to the charging system.  Amp ratings for generation and storage devices specify what can be made available.  The device load is what determines the actual amperage demand.

 Modern auto batteries are capable of providing 400-600 amps to start the car engine, which is far more than their charging systems can provide.
I don't see how you can advocate connecting a device with this capability to the motorcycle system, yet condemn connecting a device with lesser capability.

Want another comparison?  You plug your home appliance into a wall outlet.  The generation plant produces megawatts of power for a whole community.  It does not limit what you draw from your wall outlet.  Fuses and circuit breakers provide limits to protect your wiring from excessive draw.  But, the appliance determines what power it will draw from the power plant.

Hope this helps.