24e7d3a5_FAQs___3M_ESPE_Suomi__Possible_Cause
[Problem] The power level display of the handpiece flashes red while the handpiece is in the charger. [Solution] Replace the battery. [Possible Cause] 
Charging problem. The battery is defective or at the end of its useful life.
FAQs - 3M ESPE Suomi
Possible Cause