By "real battery" I meant anything other than OEM which, like tires, is generally not rated in the "high end" of any stock vehicle parts list.
Been a motorcycle guy most of my life and there was website where a retired electrical engineer and rider (for a hobby) did actual "real life" full comparison testing for motorcycle batteries even longevity studies.
He's no longer around (can't recall his name) but he was unbiased and professional, I wish there were an SUV and car battery site like it.

 

The most likely reason no one does a test like that for current vehicles (not motorcycles) is the huge variance of electronics which makes any test very difficult and challenging for real empirical information.

 

It was the same way on motorcycles, from bare bones to high end electronics including launch controls.
The guy would try all the batteries brands (or at least a majority of them) and you could choose the motorcycle(s) that were similar to the one(s) you had.
I had a K1200GT BMW at one time with nearly as much electronics as my CX-5 has (EFI, EBS, heated seat, grips, powered windscreen, auto dim headlamps, etc.)
My friend had the same bike, different color, to which he added a phone charging pad, GPS, radar detector, music system, helmet intercom, heated clothing ports.
He even had a charger for his laptop and a single cup coffee maker in his tank bag and still swear he had a microwave oven hidden somewhere on that bike.
And yes, I always had jumper ability for him when we went on trips, but I always made sure he turned off the key when we stopped.
Had a bad habit of leaving it on accessories which would've melted his battery in about 30 seconds with the engine off

 

The biggest and hardest to use in test like that is the operating temperatures of the battery. Batteries tend to slow cook over time in engine compartment of trucks and cars. Look at where the Mazda batteries are located. There is some protection, but they still get radiated heat from the enclosed area even in boxes. The only protection to reduce that is if one takes the time and thermal wraps the battery but even in most cases that will only lower about a leaner rate average of -30f and gives no opposite protection in sib zero operating environments. I always thought why more auto manufactures did not re locate the battery to the rear like a few did, as a few examples Cadillac, Oldsmobile, BMW, MINI and few other but even then, it was only on a few platforms and models. As for motorcycle batteries, wet batteries never last long in any motorcycle mostly main reason lack of maintenance from the owner.

If you come across that article I would like to read it.