voltage to at least one led 120 that can be less than or greater than the input voltage from one or more batteries 126 the buck boost controller can be obtained by a cascade connection of two basic converters a step down buck converter and a step up boost converter a circuit including the buck boost controller is preferably mounted within the housing the circuit retards or boosts the voltage to the leds the circuit preferably retards voltage to the leds when voltage from the batteries exceeds a first threshold in one embodiment the first threshold can be from about 3 6 volts to about 5 6 volts preferably the first threshold is about 4 6 volts the circuit preferably boosts voltage to the leds when voltage from the batteries drops below a second threshold in one embodiment the second threshold can be from about 2 0 volts to about 4 8 volts preferably the second threshold is about 3 8 volts the circuit preferably blocks voltage to the leds when voltage from the batteries drops below a third threshold in one embodiment the third threshold can be from about 1 2 volts to about 4 6 volts preferably the third threshold is about 2 8 volts the lamp 10 in the illustrated embodiment is battery powered as shown in fig2 and 3 within the housing 12 is a removable battery compartment 36 which is configured to hold one or more batteries the battery compartment 36 is in communication with leds 24 28 and the circuit through a depressible stem 40 on a first side 42 of the battery.