Z1OwnersClub GB

Just wondered why the newer (my Zeph11 for example) bikes have a much smaller battery than the old ones like my ST?
The ST is 19AH and the Zeph 14. Is this down to more efficient starters/different gearing etc?
Just curious because the ST one died yesterday after 5 years and was thinking of throwing the Zeph one on as a stop gap instead of straddling the emergency kick start.

14 AH should be fine for the ST. The 1000Mk2 had 12v 14 AH as standard. If the Zephyr one fits "happy days" !

Thanks, it's smaller size wise also so will fit. I'll throw it on later and pack it out to stop it rattling about.
I've just checked the WM and it states 16AH. The 19 one was a replacement I saw online.
So not as big a difference as I had thought.
Cheers