Mr Stupid left the key turned on

[member3480]

If you look at the plates in a battery they have color and texture and older batteries that have been charged over and over turn a dull color and some even have pieces break off. Those you toss but a battery that has life but just was ran down just needs a good jump to bring it back. Old wives tale is you never put a battery on the cement floor. I heard that since I was 6 yrs old from my grandfather so I always put it on wood. True or not but I have a battery out of a Harley that is close to 20 yrs old. Gave life to it maybe 7 years ago sits on work table and it still has a charge and comes up to 12volts. Now would I put it in a bike HELL NO but I use it as a jump battery and it has started many bikes.
If your battery is more than 5 years old stop being cheap go buy a new one but if you just did what FRED did its got a shot and I would be more worried of what FRED may have damaged IGNITION REG/REC coil leaving key on for that long than the battery. I have a bike here that guy was cleaning bike had key on with kill switch on and fried the electronic pickups on a GS850 in 2 hours . So you do a dumb think ONCE and it costs you money ONCE and you never forget.

 

[weekendrider]

Some old wives tales started with a seed of truth.
I think the old cases were conductive enough they would leech voltage if in contact with the ground. My brothers FIL owned and operated a battery shop where he built/rebuilt batterys. It looked nothing like todays stores, big tanks with lead plates hanging in some kinda nasty fluid. Racks with new empty cases, he would literally build the batteries.
That shop has been closed for 35-40 years and probably wouldn't be allowed to operate today.

 

[BlueNorth]

There's a good chance that you can revive the battery if it's only been a few days.

Most new chargers won't charge a dead battery due to the high resistance so you'll need to bring the voltage up using a wall-wart type voltage supply. The lower the amperage the better.

I use a 13.5 volt wall-wart with a 200 mA (.2 amp) capacity. You can find them at most thrift stores for less than $5.00. When you first put the wall-wart charger on the battery, the voltage will be low because of the internal resistance of the battery. As the battery charges, the internal resistance will drop and the voltage will slowly rise.

Leave the battery on the wall-wart charger for a day or so and then put it on a regular charger.


Wayne

 

[mrtwowheel]

Some old wives tales started with a seed of truth.
I think the old cases were conductive enough they would leech voltage if in contact with the ground. My brothers FIL owned and operated a battery shop where he built/rebuilt batterys. It looked nothing like todays stores, big tanks with lead plates hanging in some kinda nasty fluid. Racks with new empty cases, he would literally build the batteries.
That shop has been closed for 35-40 years and probably wouldn't be allowed to operate today.

That's what the old guys' shop looked like where I used to buy refurbished batteries. This guy treated acid as if it was just harmless water. His hands and ears were all deformed from the stuff.

Scott

 

[gggGary]

Modern starting batteries have rather thin plates. run em dead and the anode? turns nearly completely to lead sulphate. this is physically bigger than lead. it deforms the battery. That's why old dead batteries are all bulged out. So a full discharge damages and reshapes the anode, you might get it working but it will never be "like new" again.
True deep cycle batteries have heavy lead plates and can take heavy discharges much longer.
Even their life is greatly reduced by heavy discharges.

"Deep cycle batteries should not be discharged by more than 60% of their capacity and the less you regularly discharge a battery the longer it will last. A battery in daily use and discharged by no more than 40% of its capacity should last for more than 3000 cycles and may not need replacing for up to 12 years. A battery that is frequently heavily discharged may last no longer than 2 years."

It's simple physics, no free lunch in the lead acid battery business.
DaddyG's harley battery is an odd exception, to keep the battery from shaking apart they used heavier or "deep cycle" type plates in HArley specific batteries. So they would take a discharge with less damage than a typical starting battery. Why the XS battery is in a rubber mounted frame.

The long story https://www.av8n.com/physics/lead-acid.htm

 

[racerdave]

Fred do you have a Pamco ign? I thought I read somewhere they fry if key is left on without running the motor? I am sure someone can set me straight if i am wrong.

 

[fredintoon]

Hi Dave,
my Heritage has the stock TCI system that was left turned on long enough for it and the rear lights to suck a fully charged new battery absolutely flat and the bike fired up just fine with a replacement battery.
So no, the stock TCI ain't bothered by being left with the key on.
Points, pamco and other ignitions, I dunno about.

 

[gggGary]

TCI has a timer if the crank doesn't turn for a couple seconds it shuts itself off. The kill switch shuts off all of the ignition circuits.

 

[fredintoon]

Hi Gary,
the TCI turns itself off? I did not know it would do that.
All these years it's been patiently waiting for the opportunity to save my forgetful arse. Thank you Mr Yamaha!
Meanwhile, the battery resurrection is still an ongoing endeavor.
As someone posted here, the modern battery charger can't cope with a totally flat battery.
So I hooked the battery up to the old dumb 1 amp unit from my bike's toolkit and waited.
Then I put a new 9V battery in my multimeter so I could check for an accurate reading on my supposedly recovering 12V bike battery.
8.2 Volts.
Then I checked the 1 Amp charger.
And 8.2 Volts is all that it was putting out.
Clipped the lead wires and binned the rest.
Dragged out my other, somewhat bulkier, dumb 1 Amp charger.
it's putting out 13.4 Volts.
We'll see what happens now.