Battery & Power Management
Why voltage checks aren't enough, chemistry-specific replacement schedules, Li-ion handling safety, and runtime-complaint troubleshooting.
Battery-related complaints - won't hold a charge, shorter runtime than spec - are among the most common real-world service calls across almost every portable equipment category on this site, and they're also one of the categories most often misdiagnosed by a too-quick check.
Why a voltage check alone is insufficient
A battery that passes a quick static voltage check can still fail completely under real load - internal resistance rises as a cell degrades, and that only shows up when current is actually being drawn. A proper capacity test discharges the battery under a realistic load profile matching the device's actual power draw and measures how long it sustains an acceptable voltage, not just what the voltage reads at rest.
Chemistry-specific handling
- Sealed lead-acid (SLA) and NiMH batteries have a real shelf/cycle life regardless of apparent condition - replace on the manufacturer's schedule, not just on failure, since these chemistries can fail abruptly near end of life rather than degrading gradually and visibly.
- Lithium-ion packs need real handling care: never charge a swollen or physically damaged pack, and dispose of them through a proper battery-recycling stream, not general waste. A damaged Li-ion cell is a genuine fire risk through thermal runaway, and this is not a hypothetical caution - it's the reason dedicated Li-ion disposal containers exist in most facilities that stock portable equipment.
Troubleshooting a runtime complaint
When a "doesn't last as long as it used to" complaint comes in, check three things in order: the battery's actual cycle count/age against its rated life, whether the charging contacts (on both the battery and the device) are clean and making full contact, and whether the device's own power management (display brightness, wireless radios, unnecessary modules left active) has changed since the complaint baseline. A genuinely degraded cell is common, but a dirty charging contact or a setting change is common too, and it's a much cheaper fix.