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How to Test Batteries for Use on Airplanes

Small aircraft use batteries to assist with the starting of the engine and to power GPS units, radios and electronic cockpit gauges. Aircraft batteries are susceptible to draining and losing power and efficiency. The batteries must be tested on a routine schedule to ensure they are in working order and are safe for flight. Aircraft batteries are tested based upon two criteria: "Accuracy" and "Efficiency." Accuracy speaks of the precise numerical measurements of the battery's power and Efficiency refers to how effective and quick the test is conducted. With rare exception, the battery tests need to be conducted by a certified aircraft mechanic.

Battery tester
Airplane battery accuracy and efficiency chart

Instructions

- 1
  Open the battery housing panel for your aircraft. Batteries are housed in different locations as designed by different aircraft makers. Disconnect the cable connections to the battery and attach the battery charge reader.
- 2
  Take down the readings you read for current, voltage and amperage. The battery tester has a gauge with striations for the three criteria. The tester has two, spring-clamp jaws that attach to the battery terminals.
- 3
  Open the aircraft guidelines and operating manual - a document that must be in the aircraft at all times, per FAA regulations - and look up the battery specifications.
- 4
  Cross reference the readings from the tester and the specified requirements for the aircraft battery. Discard the battery and replace if it is not operating according the recommended guidelines.

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