Fujitsu Batteries: How to Choose and Use Them

Quick selection guide

• If you use the device daily or it draws high current (cameras, flash, toys, wireless peripherals), choose NiMH rechargeables (AA/AAA).
• If the device is used occasionally (TV remotes, basic flashlights, radios), choose alkaline (AA/AAA/C/D/9V).
• If the device is ultra low‑drain (wall clocks, simple remotes), carbon‑zinc can be a cost‑saver.
• For watches, calculators, and instruments, use specialty coin or silver‑oxide cells in the exact size specified by the device.

Compare chemistries at a glance

Chemistry	Best for	Reusable	Typical shelf life	Notes
Alkaline	Intermittent, low–moderate drain	No	Up to ~7–10 years (unopened)	Good all‑purpose; voltage sags under heavy load
NiMH (low self‑discharge)	Frequent use, high drain	Yes	Holds ~70–85% after 1 year (typical)	Hundreds to thousands of cycles; needs a charger
Carbon‑zinc	Very low drain	No	~2–3 years	Lowest cost; shortest runtime
Specialty coin/silver‑oxide	Watches, instruments	No	Varies by cell	Choose exact size (e.g., CR2032, SR626SW)

Battery types in the Fujitsu lineup

Alkaline (AA/AAA/C/D/9V)

Use for remote controls, radios, basic flashlights, toys, and emergency kits. Many alkaline cells offer a long shelf life when stored properly and are leak‑resistant.

• Pros: Widely available, good for intermittent use, long storage life.
• Limits: Performance drops in high‑drain devices; not rechargeable.
• Tip: For gear stashed for emergencies, rotate stock every 5 years and remove cells from devices you rarely use.

NiMH Rechargeable (AA/AAA)

Best for cameras, flash units, gaming controllers, wireless keyboards/mice, motorized toys, and LED lighting.

• Pros: Low self‑discharge; strong high‑drain performance; long‑term cost savings.
• Cycle life: Often 500–2100 cycles depending on capacity, charger quality, and depth of discharge.
• Self‑discharge: Typically retains ~70–85% charge after 1 year at room temperature (model‑dependent).
• Charging: Use a smart NiMH charger with delta‑V or timed termination; a 0.2–0.5C charge rate balances speed and longevity.
• Simple runtime estimate: A 2000 mAh AA NiMH can power a 300 mA device for roughly 5–6 hours; actual runtime varies by device and cutoff voltage.

Carbon‑zinc (AA/AAA/9V)

Works well for ultra low‑drain products like wall clocks, basic IR remotes, and simple LED candles.

• Pros: Lowest upfront cost for low‑drain use.
• Limits: Shorter runtime and shelf life than alkaline; avoid in high‑drain devices.

Specialty coin and silver‑oxide cells

Common formats include lithium coins (e.g., CR2032, CR2025) and silver‑oxide watch cells (e.g., SR626SW). Match the exact code printed in your device manual or on the old battery.

• Use for: Watches, calculators, key fobs, medical and test instruments.
• Notes: Silver‑oxide cells offer flatter voltage for precision devices; lithium coins provide long shelf life.

Compatibility and charging notes

• Do not charge alkaline or carbon‑zinc batteries. Only charge NiMH in a charger designed for NiMH.
• Charge matching sets together (same brand/capacity/age) if your device uses two or more cells.
• Avoid continuous trickle charging above ~0.05C on NiMH to reduce wear.
• Temperature: NiMH charge best around 10–30°C (50–86°F). Performance in cold improves with NiMH versus alkaline, but capacity still drops in sub‑freezing conditions.

Storage, shelf life, and care

• Store in a cool, dry place; avoid heat and direct sun. Room temperature is ideal.
• Keep batteries in original packaging or battery cases to prevent short circuits.
• Remove cells from devices you won’t use for a month or more to reduce leakage risk.
• Rotate stock: use older cells first; mark purchase dates on packs.

Safety essentials

• Never mix old and new batteries, or different chemistries, in the same device.
• If a cell leaks, handle with gloves, avoid contact with skin/eyes, and clean the device following the manufacturer’s guidance.
• Coin cell hazard: keep out of reach of children; seek immediate medical attention if swallowed.
• Recycle: Take spent batteries to local battery recycling points where available.

When to consider alternatives

• Extreme cold or very long runtimes: Primary lithium AA (FR6/L91) often outperform alkaline; check your device’s recommendations.
• High‑output flashlights or custom electronics: Rechargeable Li‑ion (e.g., 14500) may be used only if the device explicitly supports 3.6–3.7 V cells—never substitute Li‑ion for standard AA in unsupported devices.
• Smoke alarms: Use the battery type specified by the alarm manufacturer; many recommend long‑life 9V lithium primaries.

FAQ

How long do Fujitsu alkaline batteries last in storage?

When stored cool and dry, many alkaline models maintain performance for up to about 7–10 years. Always check the date code on the packaging.

How many times can I recharge Fujitsu NiMH batteries?

Typical cycle life ranges from a few hundred to over a thousand cycles depending on capacity, charger quality, and how deeply you discharge them each time.

Can I mix NiMH with alkaline in the same device?

No. Mixing chemistries or old and new cells can cause leakage, poor performance, or device damage.

Do NiMH hold charge in a drawer?

Low self‑discharge NiMH retain much of their charge for months; many hold around 70–85% after a year at room temperature. Top off before important use.

Which charger should I use?

Use a smart NiMH charger with individual cell monitoring and automatic termination. Avoid fast charging above 1C unless the cell and charger explicitly support it.

Specifications and performance vary by model and device. Consult product packaging and your device manual for exact requirements.