The Stovebolt Site Forums The Shop Area The Electrical Bay Worked for 17 years and then just quit?

I got a little story for you all, and hopefully someone can help me understand what happened:

This at least 17 year old generic cheapo big box autoparts store 12-volt battery I have been using has been just "short" (pun intended...keep reading) of amazing. At about age 5, the battery ceased to be a reliable starting battery, but would always take a charge and function as it should for about a month at a time before discharging to about 70%. It would always easily take a charge back up to 100%. The vehicle does not get out or run that often so the battery does not get adequate charging from the vehicle alternator. Just the other day, I attempted to start the aforementioned vehicle and nothing. Put a charger on the battery and it indicated only 10% charge.... So I plugged in the charger and went about my day, checking periodically and at one point the charger indicated that the battery was 70% charged. Came back several hours later and the charger had a flashing "bad bat" message, something I had never seen from this charging machine before. This morning, the battery has only 10% percent charge. What happened so suddenly? Yeah I know this box of lead energizer bunny has been living on borrowed time for well over a decade, but what physically happened for it to change so drastically? My guess is that it finally sulfated and shorted out, but if so, why does it still carry a 10% charge?

Im not specifically sure on the exact cause of your battery issue. But it sounds like it was a slow on going process really. I actually have about eight batteries sitting unused from various vehicles that ive scrapped over time. If the battery is dead when I get it, its goes in the junk pile. I dont try to revive em. But if it shows signs of life, ill charge it to what I think is fully charged. At that point, about once6 or twice a week, I change a maintainer from battery to battery. Note: I only have 1 maintainer. When I change to the next battery, it shows charging then at a point goes to fully charged. Just the other day I had a battery trigger to maintainer to "bad batt", same as you. Now that battery is in the junk pile also. But my point was that ive seen some batteries last only a few years and some last 10 or more. Im not sure if there is a rime or reason, but they all die sometime. Even when regularly maintained....

Check the specific gravity of the acid with a hydrometer. I'm going to guess you'll find one or more cells with a reading either much higher or lower than the rest. One big reason batteries fail is the loss of plate material off the grids that eventually builds up, touching the bottom of a cell group and shorting that cell out. A 12 volt battery becomes a 10 volt, and the shorted cell cannot recycle the acid during the recharging process, resulting in very low specific gravity in the shorted cell.
Jerry

To sort of answer your question. If one turns on their flashlight only to find the batteries are bad or no longer working, sop is to replace batteries and go about your task. If one were to measure one of the ‘bad’ batteries with a DVM set to dc volts, one would measure almost the exact voltage the battery is rated at. Problem is, it is incapable of producing current or amperage necessary to make the lamp or bulb illuminate.
Read past posts by Hotrod Lincoln on this issue. He explains it very well.

The terminology for this failure is indicated by the acronym STB. (Hint: the last two words are "the" and "bed".) This acronym is often expanded to FSTB to indicate finality to what has been done to said bed.
I yield the remainder of my time.

Carl

STB
Sacrae Theologiae Baccalaureus

FTSB
Fraternité Saint Thomas Becket

Thanks for the scientific, anecdotal and philosophical descriptions for the final battery demise process. From stovebolt, I expect nothing less. Thanks guys!

From a serial battery abuser but learning...

12 years is not a bad life for a battery. the last one that I replaced was a Wallymart "el cheapo" and it lasted several years past its prime. It failed in pretty much the same manner that yours did. I kept it on a trickle charger most of the time too. But the vehicle has a few wild electrons that like to run the battery down, so that happened every time I forgot to plug the trickler in.

12 years is nearly twice what I would normally expect out of a battery. 12 years is like winning the lottery.
I just swapped out the original battery in the wife's car. It was buried so deep it took me 1-1/2 hours for the job.

My 6v Optima battery is still working fine after about 15 years.

Little or no driving (rarely more than 1K miles per year), and parked/stored in an unheated garage. The trucks starts each spring, after a little cranking.

My Spring “start-up” procedure is:
- crank the engine for 5-10 sec with choke full open (ignition off)
- pull the choke closed
- crank the engine, slightly opening the choke when the engine/ignition “catches”/starts
Usually this starts the engine on the first or second “cycle through that sequence.

Each Spring, I expect the 6 volt Optima to “give it up”
[give it up - to cease efforts now otherwise pointless]