24e7d3a5_FAQs___3M_ESPE_Suomi__Possible_Cause
[Problem] The charge level display on the handpiece glows red steadily. [Solution] Place the handpiece in the charger and recharge the battery. [Possible Cause] 
The remaining battery charge is adequate only for typical 5 10-second exposure cycles.
FAQs - 3M ESPE Suomi
Possible Cause