I personally was looking for an increase in power when starting the engine, so coming from the Standard Banner 300 CCA, to the Interstate 500CCA sure seems like a pretty substantial increase to me since CCA is the maximum amperage available at full charge, used to turn over the starter motor, which is the increase I was looking for.
Since AH is the total power available in a battery (the number of hours a battery will last drawing one amp of electricity), and since i am not planning in using the battery to run accessories with the engine off (or using it in a deep cycle manner) it am hoping 32AH should be enough. As far as longevity goes, it's true bigger is better. The old "generally unloved" Banner 30AH lasted 4 years so pretty average I guess. Time will tell in the interstate. She fired up almost instantaniously this morning again, and the Ol' S&S has never done that as long as I have owned her so I am a happy customer so far.....
I can understand your thinking Bluesman but CCA is a laboratory figure and will diminish. My point though was that the main element of battery ageing is gradual but inevitable reduction in capacity mainly due to sulphation of plates. Having the largest capacity (amp hours) that can be accommodated wards off the day when, despite being fully charged to remaining capacity, the battery is only able to give the engine a couple of turns.
I remember being surprised when I learnt of the pitiful 30 Ah capacity of OE Banner in my M3W. Years ago Guzzi 850 T3 V twins were factory fitted with a 32 Ah battery but that only had to turn over pots less than half the size of the S & S.
