The electrical system is turned ON or OFF by means of a two-sided Master Switch. The right toggle controls the battery (BAT) and the left toggle controls the alternator (ALT). When the ALT switch is turned off, all of the current used by the aircraft's electrical components will be drawn from the battery and will deplete it fairly quickly. Sometimes during flight it may be necessary to shut off the alternator, such as when it puts too much charge back into the battery, potentially overheating it. The typical battery should contain enough charge to power the aircraft's electrical components for an additional 20-30 minutes once it is no longer being recharged by the alternator. An effort should be made to shed electrical load by turning off (by pulling out the circuit breakers) all non-essential equipment. Transmitting on the radio uses considerable electrical current so voice transmissions should be kept to a minimum.