Question T0A10
From subelement T0 - T0A
What hazard is caused by charging or discharging a battery too quickly?
Why is this correct?
Charging or discharging a battery too quickly forces excessive current through the battery's internal chemistry, generating heat beyond safe operating limits. This overheating can cause the electrolyte to boil and emit gases (out-gassing), potentially creating flammable hydrogen in lead-acid batteries or toxic fumes in lithium types. The other options are electronic circuit phenomena unrelated to battery charging rates—output ripple occurs in power supplies, half-wave rectification is a circuit design issue, and inverse memory effect isn't a real battery characteristic.
Memory tip
Look for the physical consequence that matches the physical stress described. Fast charging/discharging = high current = heat generation. When exam questions pair a physical action with potential hazards, the correct answer typically involves direct physical effects rather than complex electronic phenomena.
Learn more
Battery charging rate directly affects internal heat generation through I²R losses in the battery's internal resistance. Excessive heat causes electrolyte breakdown and gas evolution—hydrogen in lead-acid batteries (explosion risk) or toxic compounds in lithium cells. This is why battery management systems in modern amateur radio equipment include thermal protection and current limiting. Understanding heat as the enemy of battery longevity helps explain why proper charging protocols specify both voltage and current limits.
Think about it
Why do you think battery manufacturers specify both maximum charging voltage AND maximum charging current, rather than just one limit?