Since Im off work I decided to get out the new battery tester and have a play... only to find that as part of the setup everytime I hook up a battery I have to specify the battery capacity, sure no problems plug in the CCA, but which one?

Theres 8 spererate measures of CCA... SAE, BIC, DIN, IEC, EN, BSR and JIS. the Last one is MCA and is usually used for marine grade batteries and deep cycle batteries Conveniently it stands for Marine Cranking Amps but bears no direct relation to CCA. Off to the internet for something other than landrovers and porn for me.

Heres what I found

of the 6 main types SAE + BIC are more or less the same with The SAE mob adopting the BIC standard of testing. to rate batteries. by far the most common are SAE, DIN with the standards for EN and JIS being nearly interchangeable.

http://www.acdelco.com.au/PDFs/ACDelcoToday_Dec08.pdf buried in that pdf is a pretty good summation of the info that I found on the net.

but its more fun than that....

not only do the different standards provide for different testing methods to determine the CCA of your battery they also have differing standards for the layout of the battery.... just for laughs lets complicate it even further.

Some places build a battery to one or more specifications (an SAE size battery with Din fittings) but they test them to a different standard...

Time for a phone call. To the local battery world.

which yielded this gem. I'm not going to provide the full conversation just the key points.

"the key differences in construction comes down to the internal layout, physical size and the method of restraining or lifting the battery. So long as it fits the tray, has the right terminals and can be restrained adequately the methods of construction dont really matter for generic automotive batteries"

and

"if your battery CCA doesnt display which testing method was used to determine its rating assume it was SAE as thats the one that generally yields the bigger numbers. Bigger numbers sell batteries"

The only real constant I was able to find was the standard for the Reserve capacity and the Amp hours of the battery and even then there were some minor differences. but basically

The reserve capacity of your battery is how long in minutes it can push 25 amps until the voltage drops to 10.5v.

The Amp Hours is how many amps the battery can push for 5 or 20 hours before the battery voltage drops to 10.5v. (according to mr battery world if your battery lists amp hours instead of reserve capacity it will also list the hours at the given amps)

both tests start with a new, fully charged battery in a room at 27 deg C