I'll state now I'm not an expert.
My wife has a Subaru legacy GT and sadly got a flat battery about 6 months ago while I was away.
She couldnt contact me so rang RACV.
Paid for the premium battery.
She has MS so doesnt drive around alot and usually only short trips ( school runs etc, 1 - 10km's )
except for a once a week trip to the osteo (40kms return ) .
This battery is now starting to die, and the pervious one only lasted 12 months.
Spoke to a mate who is an RACQ roadside mechanic and he reckons that the alternator in her car isnt putting out the correct voltage to charge the calcium batteries that are now being supplied.
He see's this every day and it pisses him off too.
Not a fault of the alternator or the car, just a bad match of battery type and vehicle charging capability.
A bit off topic, but i thought it might be worthwhile knowledge anyway.
Cheers,
Dale