Battery warning
The symbol for battery warning 
appears and an audio signal is output
Cause: Battery voltage is dropping (measurement still possible)
Remedy: Change the non-rechargeable batteries or the lithium-ion battery pack (accessory) or charge the lithium-ion battery pack (accessory) outside the measuring tool
An audio signal is output and the measuring tool switches off
Cause: Non-rechargeable batteries or lithium-ion battery pack (accessory) drained
Remedy: Change the non-rechargeable batteries or the lithium-ion battery pack (accessory) or charge the lithium-ion battery pack (accessory) outside the measuring tool