The phrase "hour battery" means the amount of time a device can be used before the battery runs out of power and needs to be recharged. Full definition
It is said to gives 6 hours battery life in 15 minutes of charging. (techandroids.com)
An optional 12 - hour battery pack is available. (idealhome.co.uk)
On the battery avenue, the source stated that the watch offer 24 hours battery backup with modest use but around 10 hours will offered against active usage. (techone3.in)