PLT109: Aircraft Batteries
What code PLT109 covers, why the FAA tests it, and how to study Aircraft Batteries before your checkride.
Recall aircraft batteries - capacity / charging / types / storage / rating / precautions
What this means for your checkride
Aircraft batteries store electrical energy to start the engine and to back up the electrical system. Ratings cover capacity in amp-hours and voltage; lead-acid and nickel-cadmium types differ in charging and care. Servicing precautions include ventilation, correct charging, and safe handling of the corrosive electrolyte.
The battery is the backup after an alternator failure, so the FAA tests its ratings, types, charging, and safe handling.
Pilots assume the battery runs everything indefinitely after an alternator failure. Its capacity is limited, so you shed nonessential loads to extend the time it can power essential equipment.
Where to study it
A code on your test report is an area of deficiency. An authorized instructor must review it with you and endorse that review before you take the practical test, and the examiner may revisit it during the oral. Study it until you can explain it out loud, not just recognize the answer.