The most important information when choosing a car battery is the CCA rating. It is the maximum extractable current of a battery over a short period of time (about 30 sec) in an engine starting situation.

CCA stands for Cold Crank Amps. Automobile batteries will have CCA rating indicated in the fine print. Various CCA standard exist in the market namely SAE, DIN, IEC, EN (EN1 & EN2), JIS and MCA. So CCA rating will always point out the standard used to test.

Although subject to battery design, an approximation of SAE to DIN CCA conversion is:- SAE = (DIN x 1.5) + 40.