Definition
The release of gas from a storage battery during charging. In a lead-acid battery, gassing produces hydrogen and oxygen as the electrolyte breaks down through electrolysis when charging current exceeds what the battery can absorb, particularly near the end of the charge cycle.
Plain English
When a battery is being charged, it can start to bubble and give off gas. That bubbling is called gassing.
Context Anchor
Seen in aircraft battery servicing, charging, ventilation, and maintenance safety discussions.
Derivation
From the simple verb 'to gas' -- meaning to give off gas. The word is used because the battery literally releases gas (hydrogen and oxygen) into the air during this part of the charging process.
Why Pilots Care
Ensures the aircraft carries enough fuel for the planned flight, which is essential for safety and range.
Grounding Statement
Picture a battery on a charger giving off tiny bubbles; those bubbles are the gas being released.
Intuition Check
Gassing does not mean filling the aircraft with fuel. Here it means a battery releasing gas, especially while it is being charged.
Example Sentence 1
The mechanic checked the electrolyte levels after the battery had been gassing during a long charge.
Example Sentence 2
After gassing the tanks to the tabs, the pilot verified the fuel caps were secure before engine start.