Eneloop AAA Pro

Panasonic Eneloop Pro AAA (BK-4HCD)

High-capacity, low self-discharge NiMH AAA cells designed for compact, high-drain devices. Typical capacity 950 mAh (min. 900 mAh), stable 1.2 V output, and up to 500 recharge cycles. Pre-charged and ready to use.

When to choose Eneloop Pro AAA

• High-drain or frequently used AAA devices: headlamps, bike lights, wireless keyboards/mice, handheld recorders, toys.
• Cordless phones that specify AAA NiMH: longer time between charges (most handsets use 2 cells).
• Mixed environments: reliable operation from -4 to 122°F and strong performance under load.

Consider standard Eneloop AAA (BK-4MCCA) instead if

• You prioritize maximum cycle life (up to 2100 cycles) over peak capacity.
• Devices are low-drain: TV remotes, clocks, simple sensors—where Pro’s extra capacity offers little benefit.

Runtime snapshots (rough guides)

Actual time varies by device cutoff and brightness settings. Estimates below assume one cell and typical efficiency.

Device example	Typical draw	Estimated runtime
LED headlamp (high)	300 mA	2–3 hours
Wireless mouse	20 mA	30–40 hours of active use
Motion sensor (avg.)	5–10 mA	4–8 days
DECT cordless phone handset (pair of cells)	~30 mA avg.	50–60 hours talk/active time

Charging and care

• Use a smart NiMH charger with individual bay monitoring and -ΔV/temperature termination. Recommended AAA charge current: 250–500 mA (≈0.25–0.5C).
• Let the charger complete automatically; avoid repeatedly “topping off” hot cells.
• Storage: cool, dry place (50–77°F). For long storage, leave 40–80% charge and top off every 6–12 months.
• Keep matched sets together for multi-cell devices; do not mix capacities, ages, or charge levels.
• Recycle at end-of-life; never incinerate or short-circuit.

Compatibility notes

• Nominal 1.2 V vs. alkaline 1.5 V: many devices run better on NiMH because voltage remains stable under load, but some older or sensitive devices may show “low battery” earlier—check the manual.
• Use only where AAA NiMH is specified. Avoid devices that state “alkaline only” or where the manufacturer forbids rechargeables.
• For devices stored unused for years (emergency kits), primary lithium AAA may be a better choice due to longer shelf life.

Pros and cons

• Pros: higher capacity than standard Eneloop AAA, strong high-drain performance, low self-discharge, wide temperature range.
• Cons: fewer cycles (up to 500) than standard Eneloop, higher upfront cost, not ideal for ultra-low-drain devices.

Specifications

• Chemistry: Low self-discharge NiMH
• Nominal voltage: 1.2 V
• Typical capacity: 950 mAh (minimum 900 mAh)
• Recharge cycles: up to 500
• Charge retention: ≈85% after 1 year (stored at room temperature)
• Operating temperature: -4 to 122°F (-20 to 50°C)
• Size/weight: AAA (44.5 × 10.5 mm), ~14 g
• Model: BK-4HCD

Alternatives

• Panasonic Eneloop AAA (BK-4MCCA): lower capacity (≈800 mAh) but far higher cycle life (up to 2100).
• Lithium AAA (primary, non‑rechargeable): best for extreme shelf life and very cold weather; not rechargeable.
• Alkaline AAA: inexpensive for occasional single-use, low-drain applications.

FAQ

How long do they take to charge?

At 300 mA, expect about 3–4 hours; at 500 mA, about 2–2.5 hours, plus brief top-off time. Always follow your charger's instructions.

Can I mix Eneloop Pro with other batteries?

No. Do not mix brands, capacities, ages, or charge levels—especially in devices that use multiple cells.

Do they have memory effect?

Modern NiMH has minimal memory effect. Partial charges are fine; avoid deep discharges for longest life.

Are they safe for cordless phones?

Yes, if the handset specifies AAA NiMH. Use a matched pair and replace both cells together. For maximum lifespan, standard Eneloop AAA may be sufficient; choose Pro if you want longer time between charges.

Why does my device show low battery with NiMH?

Some devices expect 1.5 V alkaline. NiMH holds a steadier 1.2 V under load, but certain low-battery indicators trigger early. If performance is normal, the reading can be ignored; otherwise consult the device manual.