Hi Steven-

oh no, an EE, really? As a mechanical engineer, I want nothing to do with anything electrical. its bad black magic as far as I'm concerned.

Anyways, for CCA, I was going by the description on the Johnson Controls web page: "CCA is critical for good cranking ability. It's the number of amps a battery can support for 30 seconds at a temperature of 0 degrees F until the battery voltage drops to unusable levels. A 12V battery with a rating of 600 CCA means the battery will provide 600 amps for 30 seconds at 0 degrees before the voltage falls to 7.20 V (six cells)."

Since the dealership said 520CCA for NA engine, 600CCA for the T5, and all the independant shops had only 520CCA in their specs, I was wondering why the T5 needed more power (and if I'd shortened my battery life by buying a 590CCA battery).

As far as the time printed on your battery, I'll bet thats RC (reserve capacity): "RC helps to power your vehicle's electrical system if the alternator fails. It indicates the battery's "staying power" -- how many minutes the battery can supply ample power without falling below the minimum voltage needed to run your vehicle." I also got that info from the Johnson Controls web page.

Thanks for the help. I would like at least another 5 yrs out of this battery.
Joe