Guides
Task-first explainers — codes, testing, charging, and safe replacement. Not product roundups.
Testing
How to test a battery
A practical order: quick tester, multimeter, then capacity tools for rechargeables.
Battery tester vs multimeter
Which tool answers which question — without star ratings or “best buy” lists.
How to test a coin cell
CR2032, CR2025, LR44 and friends — what voltage can and cannot tell you.
How to measure battery capacity
Why voltage is not capacity — and when a discharge test is worth it.
Charging & rechargeables
Rechargeable vs disposable
Only use rechargeables when the manufacturer allows them.
Rechargeable AA and AAA guide
Low-self-discharge NiMH — only when the device supports it.
How smart AA/AAA chargers work
Basic, independent-channel, and charger-analyzer — what each is for.
NiMH vs alkaline in devices
When rechargeable NiMH AA/AAA are allowed, when alkaline is required, and why voltage differences matter.
Battery storage and self-discharge
How to store spare cells, what low self-discharge means, and why hot cars kill packs.
Codes & chemistry
How battery codes work
Why LR44, AG13, A76 and L1154 can all mean the same battery.
CR vs LR vs SR
The three letter codes you see most on everyday batteries.
Same size is not always the same battery
Fitting the slot is not enough — type matters too.
How to identify the battery you need
A short checklist before you buy.
Alkaline vs silver oxide
When the cheaper LR battery is fine — and when SR is worth it.
Glossary: IEC, ANSI, AG and friends
Plain meanings for the naming systems you see on packs and in manuals.
Battery codes by market
Why US packs say 357 / A76 while many manuals say SR44 / LR44.
LR44 battery equivalent
AG13, A76, L1154 and other pack labels for LR44 — and why 357 / SR44 is the same size but not the same battery.
Hearing aid battery sizes
Zinc-air sizes 10, 312, 13 and 675 — colour tabs, activation, OEM size-table posture, and why rechargeable aids are a different system.
Watch battery sizes
Coin and button cells used in watches — CR2016, CR2025, SR626SW / 377, SR920W / 371 — and why Casio module numbers matter.
Film camera battery finder
How film cameras take batteries — 6V photo cells, button cells for meters, and why mercury-era codes are a different problem.
Instax battery guide
How Fujifilm Instax Mini cameras take batteries — AA alkaline architecture, model checks, and why Polaroid packfilm is different.
Safe replacement
Safe replacement basics
Simple habits that protect the device — and people.
Polarity and contacts
Why orientation and clean contacts matter more than brand.
Dispose and recycle
Coin and button batteries belong in battery recycling — not household trash where you can avoid it.
Smoke and CO detector batteries
There is no safe generic “smoke detector battery”. Identify architecture first — 9V, AA, sealed 10-year, or hardwired backup — then match your exact model.
Remote not working after battery change
Checklist when fresh cells do not revive a TV, soundbar, streaming, garage or AC remote.