I just want to reiterate the importance of what Paul has stated above.
When buying a new battery it is essential you check the capacity and CCA.
ALSO the size of the terminals, the polarity of the terminals, AND the location of the positive and negative terminals before purchase.
It is even MORE important you check again before fitting the battery.
Ignoring these essential checks can get very expensive.
I also bought a new battery when the old one needed a really thorough charge.
Am I disappointed ? Actually no, as I now always have a fully charged spare battery.
ps. Gen 1 Alphies (probably not hybrids) like calcium batteries.