Definition
An electrical storage battery that produces and stores electrical energy through a reversible chemical reaction between lead plates and a sulfuric acid electrolyte. In aircraft, it supplies power for starting the engine, operating electrical systems when the alternator or generator is offline, and providing emergency backup power.
Plain English
A rechargeable battery that uses lead plates sitting in acid to store electricity. It is the same basic type of battery used in most cars.
Context Anchor
Seen in aircraft electrical system descriptions, preflight checks, starting procedures, and maintenance discussions about battery condition or charging.
Derivation
Named directly from its two main ingredients: lead (the metal plates inside) and acid (the sulfuric acid liquid surrounding them). The chemical reaction between these two produces the electricity.
Why Pilots Care
Provides the initial power to start the engine and operate essential systems before the alternator or generator takes over; a weak or failed battery can ground the aircraft or create in-flight electrical emergencies.
Analogy
A lead-acid aircraft battery works much like the battery in many cars: it stores electrical energy, helps start the engine, and is recharged after the engine is running.
Intuition Check
Do not read “lead-acid” as meaning the battery is simply heavy or dangerous acid in a box. It names the battery chemistry: lead parts and acid work together inside the battery to store and release electrical energy.
Example Sentence 1
Before starting the engine, the pilot turned on the master switch and confirmed the lead-acid battery had enough charge to power the avionics.
Example Sentence 2
In cold weather the lead-acid battery may need a warmer storage area overnight so the engine will start reliably the next morning.