Panasonic AAA NiMH Industrial (BK80, HHR-75AAA/B)

Panasonic’s industrial AAA NiMH cells are reliable, rechargeable power sources for cordless phones and other everyday electronics that don’t require high surge current. Choose BK80 (780 mAh) for maximum runtime or HHR-75AAA/B (700 mAh) for dependable, cost-effective performance in bulk deployments.

When to Choose These Batteries

• Use for: Panasonic and other brand cordless phone handsets (often 2x AAA per handset), TV/AC remotes, basic wireless sensors, thermometers, small toys, LED path lights, and presentation remotes.
• Avoid for: High-drain gear like high-lumen flashlights, camera flashes, and motorized toys—choose high-current NiMH or Li-ion systems instead.
• Good alternative to alkaline AAA when you want lower long-term cost and less waste from disposables.

BK80 vs HHR-75AAA/B: How to Decide

Model	Nominal capacity	Best for	Notes
BK80	780 mAh	Longest runtime in cordless phones and remotes	Choose when you want the fewest recharges between use
HHR-75AAA/B	700 mAh	High-volume replacements, fleet maintenance	Industrial bulk ("/B") packaging; dependable daily-use performance

Compatibility and Fit

• Size/chemistry: AAA (HR03), 1.2 V NiMH. Fits standard AAA compartments (approx. 44.5 x 10.5 mm).
• Cordless phones: Many handsets use two AAA NiMH cells. Replace both cells together for balanced performance.
• Replacing alkaline AAA: Works in many devices; some products that expect 1.5 V may show a low-battery warning earlier. If that’s critical, consider low self-discharge NiMH or primary lithium AAA (non-rechargeable).

Charging and Runtime Guidance

Charge only with NiMH-compatible chargers (or the handset’s cradle if designed for NiMH). Typical charge rate guidance for AAA:

• Recommended charge current: 0.1C–0.5C (70–390 mA for 700–780 mAh cells). Slower rates are gentler and extend life.
• Estimated charge time: capacity (mAh) / charge current (mA) × 1.4. Examples:
  • 200 mA charger: ~4.9 h (700 mAh) to ~5.5 h (780 mAh)
  • 100 mA charger: ~9.8 h (700 mAh) to ~11 h (780 mAh)
• Usage expectations (typical):
  • Cordless phones: full-day talk/standby for most home use; recharge nightly in cradle.
  • Remotes/sensors: weeks to months between charges, depending on duty cycle.

Operating Conditions

• Discharge: -10°C to +65°C (14°F to 149°F)
• Charging (typical): 0°C to +45°C (32°F to 113°F)
• Cycle life: up to 1000 cycles with proper charging and moderate depth of discharge.
• Self-discharge: All NiMH cells slowly lose charge in storage. For readiness, top up every 3–6 months if not in regular use.

Key Specs

• Chemistry: Nickel-Metal Hydride (NiMH)
• Size: AAA (HR03)
• Nominal voltage: 1.2 V
• Typical capacity: BK80 780 mAh; HHR-75AAA/B 700 mAh
• Dimensions: ~44.5 mm (L) × 10.5 mm (D)
• Weight: ~11–12 g per cell
• Mercury- and cadmium-free design

Pros and Cons

• Pros: Rechargeable up to 1000 cycles, stable 1.2 V output, wide operating range, cost savings vs. disposables over time.
• Cons: Lower voltage than alkaline (1.2 V vs 1.5 V) may trigger early low-battery indicators in some devices; periodic top-ups needed due to self-discharge.

Best Practices

• Use a smart NiMH charger with delta-V or temperature cutoff to prevent overcharge.
• Do not mix old and new cells or different capacities/brands in the same device.
• Replace both cells in cordless phone handsets at the same time.
• Store cool and dry; avoid prolonged heat. If storing long-term, charge to ~40–60% and top up every few months.
• Recycle at approved battery collection points. Do not dispose in household trash.

Alternatives

• Need longer shelf readiness in rarely used devices: consider low self-discharge NiMH AAA.
• Need maximum runtime in high-drain lights: consider high-current NiMH or Li-ion systems designed for those devices.
• Need very long storage without charging: primary lithium AAA (non-rechargeable, 1.5 V) may be suitable.

FAQ

Can I use these to replace alkaline AAA in any device?

Often yes, but some products expect 1.5 V and may show a low-battery warning sooner at 1.2 V. If that’s an issue, choose low self-discharge NiMH or primary lithium AAA.

Do I need to fully discharge NiMH before recharging?

No. NiMH cells have minimal memory effect. Partial charges are fine and can extend cycle life.

How many cycles will I actually get?

Up to 1000 under gentle use (shallow discharges, proper charge rates, moderate temperatures). Deep cycles, heat, and fast charging can reduce life.

Are these pre-charged from the factory?

Industrial bulk cells may arrive at a partial state of charge. For best results, fully charge before first use.

Why does my cordless phone battery life vary?

Handset power draw, base station design, signal conditions, and charger behavior all affect runtime. Higher-capacity BK80 generally provides longer intervals between charges than HHR-75AAA/B.