[justin13703]

Talking about charging curves in different types of batteries is really only something you need to worry about with batteries used in an industrial environment. As far as in your car, it really won't make any difference.

On paper, do they have slightly different charging curves? Yes. In reality, it doesn't matter. What you go with may not be the "ideal" charging setup for a certain battery, but it will work fine. Besides, most of the time, you aren't so much as charging your car battery, as maintaining it. You start your car, and from then on it pretty much is maintaining the charge. Any battery, when run very low, should be recharged with a real charger, not your car.

Whether you put a flooded or AGM battery in your car, it won't care. It will charge either of them just fine. In fact, agm batteries are commonly used as an upgrade on vehicles that came with flooded batteries, and if a car came with an agm battery, using a flooded one may be a step down, but it will work just fine.

Sorry about the long post, but I just didn't want anyone to over complicate this. Any battery will work. Some (agm) will work better than others (flooded).

 

[justin13703]

Talking about charging curves in different types of batteries is really only something you need to worry about with batteries used in an industrial environment. As far as in your car, it really won't make any difference.

That May be true in most cases, I wonder if the variable alternator in the cruze has some effect? It also at times is charging at a higher rate than a normal alternator(seem mine at 15V+ on more than one occasion).

Yes the charging system on the Cruze will vary output by load, and cause what looks like fluctuating voltage readings. This is normal.

For example, when at wot, sometimes the vehicle will drop voltage to around 12 volts to prevent parasitic loss through the alt, to give you max power at wot. Also, when costing or braking, the vehicle may bump up voltage to 15 or more, because you aren't using any power from the motor, so it will do some extra charging then.

 

[justin13703]

I am still struggling to understand what different battery types mean for our cars. What's in the link (
Absorbent Glass Mat (AGM) Battery Information - Battery University ) helps a little, but I am still not completely clear.

In the old days, I could tell when I needed a new battery. The lights and accessories would dim/slow down more than I was accustomed to, when the engine was at idle or off. Signified the battery was not delivering as much current for a given voltage that it had in the past. Not sure how to tell now, with all these smart algorithms modifying the experience. How to tell, now? Is the first definite symptom a no-start? Or (hopefully), is the car's computer smart enough to tell me it's time for a new battery?

When I need a new battery, I would like to buy the brand and type that gives longest service life. Still hoping for an answer: What should I buy?

Oops, do the charging systems differ between Gen1 & Gen2, Diesel, and not? I have a Gen 2 gasoline.

What you SHOULD buy is an agm battery. They are maintenance free and are more efficient due to the plates being closer together. Only use a flooded battery as a last resort, in a case of you need a battery right now, but absolutely can't get ahold of an agm battery.