Replacing 75Ah battery with 55Ah battery

[HustleRussell]

Considering going for an Odyssey battery which is an 'Absorbtion Glass Mat' battery, to replace a normal lead acid battery.

The AGM battery is smaller which is useful for my application, and the Cranking Amps and Cold Cranking Amps both exceed those of the lead acid battery it will replace.

However, the Ampere-Hours (Ah) of the AGM battery are much lower- 55Ah as opposed to the 75Ah of the lead acid battery.

What is the practical impact of this in the real world? Does this make this particular battery unsuitable?

[kambites]

Other than the fact the battery wont last as long when the car is parked, I doubt you'll notice a difference unless you have something else wrong and consequently have trouble starting it.