A Good Story, In A Way

[chickenhunterbob]

I got new batteries last June.

Back then one was done, but on the constant pestering of internet bulletin boards, I replaced my also good battery with a new one.

Bought the best batteries money could buy, 1000cca - 1200ca.

cost me 300 bucks for the pair.

Last Sunday I popped the hood after returning from camp (my FSD heat escape plan) and noticed a stream of (I tasted it) electrolite running down the pass side batt.

Today I fired up the old truck and went to the place I got them.

Stood at the counter for a while, some other guy came along with a couple of different bottles of ATF behind me while I waited.

Sales guy comes along, and asks if he can help.

I tell him to look after the ATF guy first, I prolly have a bit bigger problem.

The batteries come with a full 3 year warrenty and 96 months pro-rated. I told the guy my battery was leaking, I know their warrenty specifies that the battery will be replaced if it doesn't hold a charge, but that in my opinion, a leaky battery will not hold a charge for very long after all the acid runs out, and I'm off to Montana next Thursday.

OK, I'm in a good mood he says bring it in, I'll warrenty it for ya.

So now after I haul the thing in, we discover the 1000cca - 1200ca jobs I have are discontinued.

Best they have is 875 - 1075.

Hmmm. I know from message boards (I tell the guy) that I cannot, or should not have a set of batteries not matched.

He thinks that sound logical, but says he can check with a mechanic, to be sure.

I say nope, I don't care what your mechanic says, I have this on pretty good internet message board authority that both should be identical.

OK, I'll talk to the manager.

Didn't talk too long, comes back and says OK we'll give you warrenty on the other as well, and give you the two highest rated ones we have (875 - 1075)
and refund you the price difference (40 bucks).

OK by me.

So I go out and pull the driver side (perfectly good) battery and bring it in . I mention what a shame it is that a perfectly good, nearly new, expensive battery is trashed for warrenty.

Take it home if you like he says, I'll just throw it in a big rubber tub, all I need for warrenty is the stickers on the top.

So now I have 2 new batteries, a new full warrenty. 40 bucks in my pocket and a pretty decent battery that i can use in the boat.

And the moral of the story...

At some point in our negotiation, he smiles and tells me, a warrenty claim like this doesn't happen every day you know, it's entirely up to my discresion, but since you were so polite when you came in here...

[noelb]

Great result! As you have shown a polite approach will generally put them onside and allow a better negotiation.

At least you have a use for the spare battery. I have two brand new optimas sitting in the shed (got them at below wholesale price) and I am waiting for the ACDelco's to die B4 I put them in...

Cheers Noel

[Bnave95]

Great result! As you have shown a polite approach will generally put them onside and allow a better negotiation.

At least you have a use for the spare battery. I have two brand new optimas sitting in the shed (got them at below wholesale price) and I am waiting for the ACDelco's to die B4 I put them in...

Cheers Noel

I would keep the Optima on a Battery Tender till then. No I would'nt I'd use the Optima and sell the AC Delco

[Robyn]

Just a thought here.
I have ran optimas along side 8D commercials and with cheapo grocery store stuff of all different makes and CCA ratings and never had any trouble as far as life or performance .
I have an optima in my 86 dually that has been running with a farm store brand standard unit for 5 years now.
I prefer the optima because they dont eat the truck all up with the usual slop that will get loose.
Just thought I would toss that out there.
Robyn

[Craig M]

In my experience the second battery only comes into play for extended engine cranking. If your truck is starting easily one Optima (or maybe some other single high CCA battery) will easily start your truck. My 6.2 and even the 8V71 will start in our warm California weather with one Optima. Second battery for extended cranking.

[HH]

I ran my truck for the first year I owned it on one battery. One day while working on it, I discovered the PO, or one of his employees, had not attached the ground on the left side battery. Anyway, Good result for you! Good to hear, what was the shop?

[JohnC]

In my experience the second battery only comes into play for extended engine cranking.

This is true as far as cranking goes, but falls short of the real issue.

Batteries are sort of like water towers in that they store energy. If one of your water towers has a leak, it'll draw the good one down too. This is where the trouble comes in with batteries of different ages. Different capacities is not an issue as long as they are both in good shape.

[DmaxMaverick]

Having batteries of different capacities can be an issue. Different batteries (or of different condition/age) will discharge and charge at different rates. This can cause a good battery to be overcharged, or cycled to deep, which will shorten its life. Many times, having a poor condition battery will kill a new battery, even if the poor battery continues to perform as before. I've mixed/matched batteries and have had good and bad results. If one battery has an internal short, the good battery can cause it to burn up, and in some rare cases, explode. Seen it happen, all too close.

[JohnC]

Having batteries of different capacities can be an issue. Different batteries (or of different condition/age) will discharge and charge at different rates.

I disagree on the capacity issue. All other things being equal, two batteries in parallel, regardless of their individual capacities, act like a single battery. They charge and discharge at the same rate and maintain the same voltage, by virtue of the properties of a parallel circuit. Sorta like Marxism: to each according to need, from each according to ability.

The problem comes when one battery "wants" to be at a different voltage than the other. This leads to charge and discharge imbalances and one battery discharging into the other.

Not saying it's a good idea, just that the capacity difference isn't the issue.

[DmaxMaverick]

A pair batteries charge/discharge rate is like 2 tanks, connected in parallel, with different size plumbing. The tanks will fill/empty at different rates. That won't hurt a water tank, but that excessive cycling translates to heat in a battery. Heat (whether external, or generated) degrades the life of the battery. Exceed a battery's discharge rate, and take its tempurature. Load testing is a method of testing a battery's discharge rate. As a battery ages, or degrades, it's discharge rate will decrease. This increases heat generation, for the same rate of discharge.

Batteries in parallel will seem balanced. But if one is weaker, the stronger battery will carry the extra load, until it works itself to death. The weaker battery gets a free ride, as long as it isn't called upon to exceed its ability.

[noelb]

If you compare the RED top and Yellow top Optimas, one has a fully charged voltage of 12.8 Volts (red) and the Yellow 13.1 Volts. In this case if you mixed these two different batteries the red would continue to try and bring the yellow down or visa versa I think? In any case I think this is the perfect example that shows why two batteries of different types, age etc MAY fight against each other.

I have a confession to make, however, in my Landcruiser I am running a Yellow Top Optima alongside an acid slopping N70ZZ, and they probably have different voltages! Probably not such a good Idea now that I think about it! However the only time the batteries are connected to each other is when the ignition is on. Oh and I have been running it this way with different batteries side by side for eight years.

Cheers

[GMC Hauler]

There is allot of information here that is true, and some that is not true.
Even though those lead plates and posts are large, every battery cell has internal resistance. This internal resistance is one thing that limits the charge and discharge rates. (Those optima cells have extremely low resistance. If you want to charge your batteries in your travel trailer faster on your generator, use optima type batteries) It is also one of the reasons for the increase in battery temperature. There are a couple of voltages that are important to battery operation:

1. TVG (temperature voltage gassing). This is the voltage at which above excessive battery gassing occurs. When you charge a battery, you raise the voltage on the battery. The higher the voltage, the higher the charge rate. When you increase voltage past TVG, the battery doesn't charge any faster, but it causes excessive gassing, giving off plenty of hydrogen and causing battery temperature to rise. Because you give off hydrogen, you loose liquid.

2. Maximum cell voltage. This is the maximum voltage that should ever be applied to a cell of the battery.

3. Minimum ICV (Minimum individual cell voltage): This is the minimum safe voltage on a battery cell. Cell voltages drop rapidly after reaching this value, and can lead to reversing a cell voltage. Failure to reduce or terminate the battery discharge when the individual cell voltage reaches this value will cause damage. This is why when you drain a battery to DAAD (dead as a doornail) and recharge it, it is never quite right.

You cannot charge a battery faster than it will take it due to internal resistance and TVG.

Some cars today sense the under hood temperature (Chrysler does on its PCM boards; they have a thermistor to do just that). They adjust alternator output voltage; thereby adjusting charging rate for different temperatures this extends battery life by accounting for TVG.

Charging and discharging a battery causes the soft lead to flake off the plates and build up in the bottom of the cell. Good batteries have deep cases to collect these flakes. Cheap cells aren’t deep. The lead flakes build up in the bottom, causing a short between plates, and causes a cell to go bad. The deeper the case, the longer time until a cell cal short out. Another way to have a short is if the insulator between plates fails.

Electrolyte agitation is also important. This is usually not a problem in a car battery, but any stationary battery, the electrolyte can develop layers, yielding parts of the battery not exposed to the proper mix useless.

There are several types of charges, but only one that car batteries receive: a normal.

Normal charge: Bring a battery to TVG, and hold. Charging amp rate will be high initially, and decay away after the cell converts electrical energy back into chemical energy.

Equalizing charge: Sulfates get lodged in the soft lead plates, and don't come out. This causes battery capacity to degrade over time. An equalizer charge is where you perform a normal charge, and then drive the battery higher than TVG (to MCV (maximum cell voltage)) for a period of time at a particular charge rate to drive the sulfates out. This restores the battery's full capacity. Those expensive power inverters that do equalizers really will increase the life of your travel trailer batteries.

Batteries of different capacities can be used together, but because of variances in internal resistances, there is no way to know with the instrumentation in the truck if you are at minimum ICV. It is safest to just use 2 batteries of the same capacity. It probably doesn't matter in the summer, but in the winter or during winching operations, etc, it will

Load testing is a way to test the capacity of the battery. By placing a load on the cells, you determine the state of all the things we discussed in the battery.

Hope this sheds some light on battery operation and proper use of them.

[ZZ]

I have a red top 925 cca Optima as my main battery, and the Wal-Mart 1000 cca Everstart as the 2nd. I bought them both new; a week or two apart. I've never had any issues yet.

[DmaxMaverick]

I have a red top 925 cca Optima as my main battery, and the Wal-Mart 1000 cca Everstart as the 2nd. I bought them both new; a week or two apart. I've never had any issues yet.

Unless you have an isolator installed (aftermarket), your batteries are parallel. That means neither is primary or secondary (or main and second). They are connected all the time, and the only difference between the charge/discharge demand on either is only determined by the resistance in the wiring.

[ZZ]

Thanks, I guess I use the terms loosely. I say the primary to mean the battery on the passenger side.