Battery Handling Mistakes That Cause Injuries and Fires

FRC's SLA battery is heavy, stores a lot of energy, and is the single most-handled hazardous item on the team. Here are the recurring mistakes and how to stop them.

Mistake 1 - Carrying a battery by its cable. This is the classic one. WPILib explicitly warns against it: pulling on the cables fatigues the internal lugs and tabs, raising internal resistance and creating a hidden weak battery that browns out later. Fix: always carry from the body with two hands; add a battery handle/strap; coach every new member on day one.

Mistake 2 - Recharging a hot battery immediately. A battery just off a hard match is warm; charging it right away accelerates degradation. Fix: WPILib says to wait until the case is no longer warm to the touch - fifteen minutes is usually plenty - then charge on a smart charger. Build a 'cooldown shelf' separate from the 'ready' rack.

Mistake 3 - Ignoring physical damage. A bulging, swollen, leaking, melted, or burned battery is a real fire/acid hazard. Fix: inspect every battery before and after every match; quarantine any damaged unit in a sturdy plastic bin and recycle it - do not put it back in rotation.

Mistake 4 - Running a worn-out fleet. Batteries lose their competitive edge after heavy use. Teams keep dead bricks 'for practice' and then accidentally play a match on one. Fix: number and log every battery; retire on internal resistance above 0.020 Ohm or 12.5V on an idle robot (see the battery-management mini-project). Mark retired batteries clearly.

Mistake 5 - Exposed terminals and bad mounting. A battery that can short across its posts (loose tape, exposed metal) or that isn't strapped in fails inspection and can arc - a fully charged battery can briefly supply over 180A and arc at over 500A. R607 requires every terminal on the battery, main breaker, and their connections to be fully insulated at all times. Fix: fully insulate posts and the main breaker terminals; secure the battery with a bracket or strap (e.g., the AM14U Vertical Battery Tray, am-3964a, for AM14U frames).

Mistake 6 - No spill plan. Fix: keep a battery spill kit (baking soda, nitrile gloves, plastic bin) in the pit, and know that cracked SLA cells leak acid.

Diagnostic habit: make 'inspect, test, log' the ritual every time a battery comes off the robot. Most battery failures are caught by simply looking at and Beak-testing the battery before it's trusted again.