Got a free Battery today...

[Ccmano]

In Feb of 2008 I bought a new Walmart Maxx 75N battery for the Z. For the last few weeks I've been having battery issues with the battery being almost dead when I come out to start the car. At first it took a charge but in the last week it stopped even doing that.

These Maxx batteries have a 3 year free replacement guaranty, so I took it back figuring I would at least get a hassle. To my surprise it was no questions asked, I presented the old battery and receipt and was simply directed to get a new one.

The new one is installed and all is good! I don't know why so many people seem to have aversions to Walmart?
H

[Paul Workman]

No aversion here, Hans. I have one of those batteries in my Z, and have had several others in various vehicles. Pb/H2SO4/Zinc is a fairly well understood technology. Competition being what it is tends to level the playing field within the narrow scope of the ingredients to the point true distinctions between "lead/acid" batteries become rarefied---advertisements notwithstanding (of course).

With those little 800mA Battery Tenders I've had great luck getting 5 years + out of "Wally World" batteries. I'm with you!

P.

[LGAFF]

Seems to be a trend these only last about year(Walmart battery). On my 2nd one in the 92. Went through 2 in 3 years with my 90 L98

[-=Jeff=-]

Originally Posted by LGAFF

Seems to be a trend these only last about year(Walmart battery). On my 2nd one in the 92. Went through 2 in 3 years with my 90 L98

It does HELP when you drive them Especially that 1992 you have

[LGAFF]

Originally Posted by -=Jeff=-

It does HELP when you drive them Especially that 1992 you have

I have a 1992? Guess I forgot about that one.

[LGAFF]

Tried to reason with my wife, as the 92 is going to be rarely driven and as the 90 is only alloted 3K miles per year, I really need a third to give me 6K per year to drive on. Really, it only makes sense.

[-=Jeff=-]

Originally Posted by LGAFF

I have a 1992? Guess I forgot about that one.

[xlr8nflorida]

Originally Posted by -=Jeff=-

I use a CTEK Float/Pulse Charger on my Z.

Never have a battery problem and the battery usually lasts through its term of 3 years, 5 years, 7 years etc.

http://www.youtube.com/watch?v=qHSI_qHOI4U

[ZRXMAX]

My 40 lb Optima will be seeing its 6th anniversary soon after 50K of driving.

I would like to find a lighter battery for the next segment of good battery performance.

[Paul Workman]

Originally Posted by LGAFF

Seems to be a trend these only last about year(Walmart battery). On my 2nd one in the 92. Went through 2 in 3 years with my 90 L98

Wow! That is totally outside of the realm of "normal", and contrary to anything I've experienced with them. How the battery is being used, comes to mind, e.g., were the batteries just idle, or was there also some small but constant current drain present? Battery life in lightly used applications (Vettes, lawn tractors in winter) makes me a huge fan of the little automatic Battery Tenders, FWIW.

Continue at your own risk

FWIW, in the process of the H2SO4 (Sulfuric acid) reacting (combining) with the lead plates to form lead sulfate (PbSO4), electrons are freed up, thus providing electricity. This is a normal phenomenon and is quintessential to the operation in lead-acid (H2SO4) batteries. The chemical reaction is reversed in the charging process; the free H2 displaces the Pb in the sulfate compound to reform H2SO4.

However, over time the lead sulfate morphs into a crystalline substance - a process that is not easily reversed - at least in the normal battery environment. The crystalline structure insulates the exposed lead plates from the sulphuric acid and thus reduces the effective area of the exposed lead plates. And, since the crystalline stuff will not readily convert back, some of the lead and sulfate are lost to the battery process "forever", i.e., the capacity of the battery is diminished.

Crystallization is not immediate; it takes time for the crystallization to occur, and the process is greatly impeded by the act of charging the battery. Therefore, in a daily driver situation, the battery is not idle long enough for much crystallization to occur before the battery is being charged again. Thus the formation of the crystalline stuff is arrested, and during charging most of those random locations where crystallization has begun tend to be sloughed off as precipitate to collect in the bottom of the (wet) cell. (In time the level of the sulfate rises to the bottom of the lead and zinc plates, effectively shorting out the cell. When this occurs the car battery will loose approx 2.2 volts across the terminals; 2 volts being the approximate output of a lead-acid battery cell)

The key to longevity is the charging process. Charging repels the sulfate process. And therein lies a possible problem: Shelf life. There was a time when batteries were shipped w/o the (acid) installed, just for that reason. We used to wait until the battery was sold before putting the electrolyte in and then it had to be charged for a few hours before it was ready. But, the handling of sulphuric acid and the safety precautions/liability for the average department store clerk is too much to be expected. So, batteries are filled and allowed to sit for heaven knows how long...quietly sufating away, regardless of whether it is a WalMart or AutoZone or whatever...it happens. (According to one source I read, a lead-acid battery will sulfate at roughly 1% per week, initially, and accelerate as the process progresses. The article said that a (lead-acid car battery) left at room temperature for a year w/o being charged would be essentially usless for the intended purpose. (I wonder about checking or asking about dates and shelf life before buying a lead-acid off the shelf. Fresh = better, I recon.)

Sometimes a battery left unattended for a period can be de-sulfated (to an extent) by way of a high level charging current. The high current causes the sulfate to break up to precipitate to the bottom of the cell, thus exposing the remaining lead surface for electrolysis - rejuvenation, as it were. To control the heat that is generated by the high current (that would severely damage the battery), the charging current is pulsed, aka a "duty cycle". The current pulses dislodge the sulfate, and the off time allows the electrolyte to cool between pulses. (However, I would never "de-sulfate" a battery while in my car(s). After all, the process intentionally stresses the battery, and if something goes wrong with the charger, or the pulse width combined with the ambient temperature results in excessive temperature, then hydrogen will come out of suspension and the battery will boil: add a spark and BOOM!)

Well, all the way around the barn to the Wally World batteries again...I believe (perhaps to get around the shelf life problem) their top of the line batteries come with a 3(?) year warranty for a 100% replacement - or at least mine do. After the initial warranty period the replacement refund is pro-rated over the remainder of the warranty period. (Been a while since I have had to buy one.)

In my biz, batteries and their care play a big role. That said, I'm not a chemist, so please forgive me if the chemical process I eluded to are not absolutely and 100% purely correct. (aka a disclaimer")

P.