May I humbly suggest there is too much hand wringing and agonising here over model number, AH capacity and slight differences in CCA. The only absolute is the physical size that will fit in the tray, orientation side of +- terminals and the shape of the terminals. For a 9-5 (any year of 9-5, I believe) this is defined by the 096 battery code.
Capacity in ampHours is less relevant unless you are planning to regularly leave your sidelights on while parked up, not run your car for 2-3 weeks at a time (because the underlying "car all switched off" drain is about 100mA -- at least that is what it is measured on mine with only the standard clock & other OEM monitoring modules in place), or you are figuring out how far you might be able to go if your alternator fails (For average 9-5 FULLY CHARGED batteries that will probably be about 20min at the average nominal assumed base draw of 25A to keep the engine/fuelpump etc running - & NOT including headlights). More relevant is that if you install a Calcium-Lead or Silver-Calcium-Lead battery I do not think it will EVER be recharged to full rated capacity with the standard charge voltage set on all 9-5's. Maybe just to 80% rated capacity at very best I reckon.
Manufacturer's quoted CCA is a bit of a fantasy because I have seen experimental data on perfectly NEW good batteries being taken through Standards Institute specified charge cycles to retest what the CCA is on each cycle and it can vary on different cycles by as much as 10-15% if I remember rightly. Additionally as the battery is used over time, there may be some sulfation, active material drops off the grids and this will reduce the max possible CCA (and chargeable capacity).
Just as well then that (as far as I know) the usual supply required for the starter motor in starting petrol OR diesel is no more than approx 200-250 A. This is comfortably within what any new 096 size battery should be able to deliver (whether 650, 700, 750 or 800 "rated" CCA) and it is un-necessary to agonise too much over a small difference in "quoted" CCA ... as it is likely to be 10-15% out anyway. Incidentally my wife's 1.9tid 9-5 was fitted with a "630 CCA" battery 2yr ago by the dealer who sold the car to us and we still do not have any starting problems with it.
More relevant perhaps but more subtle and difficult to evaluate, is the quality of internal manufacture of the battery - whether the lead oxide paste is more carefully inserted into the grids and how grids are packed/spaced etc - which makes one Manufacturer Brand slightly more susceptible to loss of capacity through loss of active material for example or being less tolerant of deep discharge cycles as it is used over a few years. Due to its internal design, the axiom for car lead-acid batteries though, I believe, is that if it is always kept as fully charged as possible (without any deep discharge cycling) the longer a life it will have.
WR
