For how long should a battery power a pigeon rotary?

Pigeon shooting
PETER THEOBALD says:
When a battery is new and fully charged, it should power your rotary for a minimum of eight hours, but constant recharging will eventually reduce it’s effectiveness dramatically.

Opinions differ, but I reckon a battery has had it after about 50 recharges.

There is nothing more frustrating than to have your machine conk out after an hour, and for this reason alone, I will always have a new battery in the car as a backup.