Battery is not being charged

Battery is not being charged and the red temperature monitoring/error indicator (4) is flashing red.
Cause: The charger has identified an internal error.
Corrective measure: Ensure that all batteries are fully inserted. Remove the mains plug and reinsert. If the error occurs again, have the charger checked by an authorised after-sales service centre for Bosch power tools.
Cause: Battery is not correctly inserted.
Corrective measure: Insert the battery into the charger correctly.
Cause: The battery contacts and charging contacts are dirty
Corrective measure: Pull out the mains plug and (dry) clean the battery contacts and charging contacts.
Cause: Battery defective
Corrective measure: Replace the battery.

Battery is not being charged and the indicator (4) is lit up red.
Cause: Battery temperature is outside the permissible charging temperature range
Corrective measure: Wait until the battery temperature is back within the permissible charging temperature range see Charging process.