In spring of 2006 I got a free replacement battery (from Wally-World) for my 79 L82. The battery I replaced had been purchased in 2004 so it only lasted ~2 years, well within the 3 year free replacement period.

I just replaced the one I got last year. The shop that tried to charge it showed it only had 17% of the 770 CCA capacity and registered as "bad".

I have addressed some electrical things and haven't uncovered a short or any obvious problems. I recently rebuilt the starter and cleaned up all the hot and ground connections. If you remember from a previous post my hot lead was grounding out at the starter causing big popping sparks and sizzling when I tried to connect the negative terminal. This was short-lived (~5 seconds?) but strong and scary. Is this a battery killer??

I drive at least weekly and try to always get it up to highway speed...the voltmeter registers strong toward the high end of the normal operating range. The alternator was replaced just before I bought the car in Aug 2005.

I use a quick disconnect (on the negative terminal) after every ride to make sure I don't have a draw in case of unfound problems.

It was out of the car in my workshop for about 3 months. I used a very basic trickle charger on and off over the winter to keep it fully charged and it was registering no less than 12.6 volts on my multimeter.

Why did this battery die and what can I do (apart from driving everyday) to keep the replacement healthy? Would the big spark fiasco do it? It's not an issue so much because Wal-Mart will just fork over another if/when I kill this one, but I'd like to upgrade to a higher quality battery and don't want to kill it too. Thoughts?

Many thanks,
Steve

 

Part of the problem is the battery itself. I used to go through an Autozone battery once a year until I stepped up to a better battery. No problems so far.

What alternator did you install? Was it a high output SI or a stock replacement? That spark might have damaged the alternator, but I doubt it had much to do with the battery.

Also, if a battery is discharged and re-charged over and over it's capasity diminishes considerably until it's bad. Get a better battery capable of such fluctuation, like an Optima Yellow or even Red.

 

Exchange it. Yes, shorting out a battery can cause internal damage.

 

Done...new unit in place and ready to roll.

DB not sure about alt. It was installed by the PO and looks like a stock replacement. I need to check the output but I don't think the shorting caused it any harm. TBD

S

 

Have it tested. Reverse polarity can smoke the diodes. Electronics don't care what you think. Testing is fact.

 

Sulfidation is the primary cause for loss of capacity in a lead acid battery, it is the formation of christals on the surface of the battery plates, the cristals destroy the surface area on the plate where they form, its a kind of corosion.
A dead short will dammage a batteries plates in much the same way because of the excess current generated by the short, which is what happened when you connected the neg cable with the pos cable touching the shield on your starter.
The batteries they are making today have larger CCA capacities by virtue of having larger plates inside, this is surface area, not necessarily mass, the plates are very thin layers rolled together and seperated by a dielectric insulator. The plate assy inside 1 cell may only be an inch or so thick and maybe 6x8" but have a huge surface area. This is good, but it makes them more suceptable to mechanical failure because the thin plates are more fragile.
Back in the day (early 70's) I spent some time in a battery shop, we regularly serviced batteries that were stone cold dead and brought them back to life. Those days are gone, the old ones had much less CCA capacity, but with some maint would last forever.