AGM battery and computer

[ecky]

I read this while looking for a battery for my 2002 C5...

"Spiral Wound/AGM batteries have different (a lower maximum threshhold) charging requirements than regular lead acid batteries, and simply changing from lead acid to a SW/AGM battery without registering the change in your car's computer system so that it charges properly, will lead to drastically shortened life. The registration generally needs to be done by the dealer with specialized diagnostic tools.
I suspect the people who complain that the battery is junk and doesn't last replaced a used lead acid battery with this spiral wound/AGM version and didn't have the dealer register the change in the cars computer. In older vehicles (mid to early 2000's) the systems don't have the ability to distinguish between batteries and alter their charging characteristics, so consequently the battery is guaranteed to overcharge and fail in a relatively short time."

Does this make any sense?

 

[Riley P]

Not really... I would be embarrassed if I designed a battery that required modifications to a computers software before it could be used (or it wouldn't last) and as a customer, I wouldn't want that in my car because then you are stuck with that specific type of battery. Right now if my battery fails, I can go to any autoparts store and get a new one. If I had a battery that my car was modified to use, how long could you be stuck if you needed to find another one? I hope the AGM has some awesome benefit to counteract the potential frustration.

Let us know if you find out any further information. That is a really interesting question.

 

[Manny@Dasilva]

Buy the the Optima Red Top , only battery you will ever need for your Corvette .

 

[ecky]

Not really... I would be embarrassed if I designed a battery that required modifications to a computers software before it could be used (or it wouldn't last) and as a customer, I wouldn't want that in my car because then you are stuck with that specific type of battery. Right now if my battery fails, I can go to any autoparts store and get a new one. If I had a battery that my car was modified to use, how long could you be stuck if you needed to find another one? I hope the AGM has some awesome benefit to counteract the potential frustration.

Let us know if you find out any further information. That is a really interesting question.

This is one response I got....

It depends on the charging system. Newer BMW for example does require that a new battery be "registered" to the car so it will be charged correctly by the BMW "adaptive" charging system. I have not heard yet of Corvette requiring this. I would call Optima tech support if you need more info.

I would have thought AGM had HIGHER max threshold req. but I could be wrong on that.

Another response...

I find this interesting because there are chargers made for AGM batteries. I've read there needed and also read there not when charging an AGM. I've also read when an AGM gets too low, it needs to be waken up so to speak, in order to charge it back up. So they do charge differently.

And as far as I knew, early C5's or all for that matter had a lead acid battery, thus in the beginning some batteries leaked onto the ECM from the terminals being pulled out and caused all kinds of issues. After the leaking, anyone out of warranty switched to an AGM.

I could be wrong with all of this but this is how I remember.

Anyway, this is what I have received so far... :^)

 

[ecky]

Let us know if you find out any further information. That is a really interesting question.

Here is the latest info I received. I trust this will be on interest to several of you ...

"While there are charging differences between AGM or spiral core or conventional lead acid type batteries, the differences are ONLY when the battery is OUT of the car and your attempting to recover the actual battery from a fully discharged condition.

When the batteries are in the vehicles, ALL vehicles charge based on voltage readings which are monitored by the engine control module.

This means that no matter what batteries is installed in Corvette, they will charge the SAME way based on the electrical demands of the vehicle while running.

Also, there is NO CHANGING THE CHARGING CHARACTERISTICS OF CORVETTE.

There is no programming changes that can be done at the dealership level, nor anything that NEEDS TO BE DONE.

If the battery terminals are CLEANED AND TORQUED correctly, ANY battery will last 5-7 years, depending on driving style or storage.

NOTE: The ONLY thing that is REQUIRED when you install a battery or alternator or instrument panel cluster is the recalibration of the voltage gauge after installation.

This requires a voltage meter monitoring voltage at the battery and a Tech 2 to enable the calibration input." (this was from a GM World Class Certified Technician apparently).

 

[ecky]

As a potential "closing" of this topic, I got this info from the GM World Class Certified Technician (his moniker) with whom I have been conversing. Thanks to all who contributed!

Normally, Corvette engineering suggests to disconnect the negative battery terminal for storage.

Certainly, the engineering choice of CTEK chargers for the 6th generation battery maintainer makes it my choice if I was to use one.


Definitely leave it in the car. Batteries can emit gases that are hazardous. You NEVER EVER want that in your house.

Let it stay in the car, as long as it doesn't freeze, you will be fine.

 

[Riley P]

Awesome. That makes more sense. Thanks for getting the answer for us. It's nice to know you don't have to worry about what battery you use in your car. That is really interesting about having to calibrate the voltage gauge when replacing your battery.

 

[ecky]

Awesome. That makes more sense. Thanks for getting the answer for us. It's nice to know you don't have to worry about what battery you use in your car. That is really interesting about having to calibrate the voltage gauge when replacing your battery.

No prob Riley. It does make more sense. So in summary, I believe the following to be true.

1. Some cars (e.g. newer BMW's) but not Corvettes (yet) do need their batteries to be registered with the on board computer for their adaptive charging system.

2. Technically a Corvette voltage gauge should be re-calibrated when installing a new battery.

3. No matter what type of battery is installed in a Corvette, it will charge the same way based on the electrical demands of the vehicle while running.

4. There is no changing the charging characteristics of a Corvette.

5. If the battery terminals are CLEANED AND TORQUED correctly, ANY battery will last 5-7 years, depending on driving style or storage.

6. Disconnect the negative battery for storage.

7. Leave the battery in the car on a good maintainer as long as it won't freeze (which it won't if it is kept charged).

8. Never store a battery inside because of the potential of dangerous gasses leaking out.

That should pretty well summarize this discussion. Not a bad accumulation of knowledge for me at least. Hopefully some of you picked up at least the odd tidbit if you took the time to read the entire thread.