Tridonic Compact Fluorescent Lamp with combination of electronic ballast and emergency lighting unit. For manual testing of the emergency lighting function. Filament heating in emergency operation for TC-D/T lamps. Checking the emergency lighting function by interrupting the unswitched phase. Automatic restart after re-lamping in normal operation. Electronically controlled battery charging and deep discharge protection. Short-circuit-proof battery connection. Polarity reversal protection for battery.