Solution
In low temperatures, battery performance may be weak. Warm the batteries, such as by placing them in your pocket.
If the battery terminals have become dirty, battery performance may be weak. Clean the terminals with a cotton swab and re-insert the batteries several times.
If the batteries are consumed quickly at normal temperatures (23 deg C), the battery life might have been exceeded. Please replace the batteries with new ones.
Caution
When you warm the batteries in your pocket, please do not put them together with metal objects such as key chains. The batteries might short-circuit.
Please do not short-circuit the plus (+) side and the minus (-) side of the batteries with metal objects such as key chains.