Definition
A short, high-rate charge applied to a storage battery to quickly raise its state of charge before use. A boost charge is intended to bring a partially discharged battery up to operating condition in a limited time, not to fully restore or condition the battery the way a slow, controlled charge would.
Plain English
A quick, strong charge given to a battery to top it up fast so it has enough power to use right away.
Context Anchor
Seen in aircraft electrical-system maintenance, especially when a battery has run down and needs to be restored before the aircraft is returned to service.
Derivation
Boost comes from an old word meaning to push up or lift. A boost charge pushes the battery's energy level up quickly, rather than filling it slowly.
Why Pilots Care
A properly boost-charged battery ensures reliable engine starting and electrical power for avionics and lights, reducing the chance of a dead battery on the ramp.
Intuition Check
Boost charge does not mean engine boost or extra power from the engine. Here, it means a controlled electrical recharge of the aircraft battery.
Example Sentence 1
The mechanic gave the aircraft battery a boost charge so the airplane could be started for a short repositioning flight.
Example Sentence 2
After sitting unused for two weeks, the battery received a boost charge to bring it back above 80 percent capacity.