EXFO MaxTester Series - Manual (Page 135)

Maintenance
MaxTester Series 125
Recharging the Battery
To recharge the battery:
Connect the unit to a power outlet using the AC adapter/charger (or the car
outlet adapter). The charge cycle will start and end automatically.
I
MPORTANT

Batteries are not charged at the factory. You must fully charge
the battery before using the unit for the first time. The battery
is fully charged after a few hours or when the battery LED
indicator stops flashing.

The time required to charge batteries depends on various
factors such as the ambient temperature.

The battery will not recharge when the ambient temperature is
below 5 °C (41 °F) or above 40 °C (104 °F).

If you need to store the unit for an extended period of time,
place it in a cool dry place.