Panasonic Lumix DMW-FL220 Operating Instructions Manual page 8

≥ When storing the batteries for a prolonged period, it is
recommended that they be charged once a year and that after
their remaining charge has been used up, they be removed from
the unit and stored again.
∫
Service life of batteries
Number of flashes
(number of full flashes in MANUAL mode at intervals of
30 seconds)
Batteries used
Alkaline dry batteries (LR6)
Nickel metal hydride batteries
(Ni-MH)
Photo taking conditions
≥ Temperature: 23 °C
≥ The number of flashes differs slightly depending on the storage
status of the batteries and the operating conditions.
8
VQT1U62
Number of flashes
Approx. 140 flashes
Approx. 230 flashes
(min. 2400 mAh type)