eneloop AAA review
Panasonic eneloop AAA Rechargeable Batteries (4-pack)
By Tom Calder
The AAA twin of the standard eneloop; this European BK-4MCDE version is rated at a minimum of 800 mAh on its datasheet. It shares the slow self-discharge of the AA version, so it suits devices you use occasionally. AAA cells hold much less energy than AA, so check what your torch or radio actually takes before standardising on this size.
- Best for
- Small-device AAA needs such as remotes, small torches and some radios.
- Skip it if
- Your devices take AA, or you want cells you never need to recharge
as of 2 Nov 2026, 16:07 GMT · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.We earn a commission if you buy through the retailer links on this page. It doesn't change our verdict. How we make money →
Researched, not used. We haven't used this product. This review is built from the maker's specifications, owner reports and our own sizing.
What we like
- Slow self-discharge per Panasonic, so the cells are usable after long idle spells
- Works in any standard NiMH charger
- Established brand with clear published specs
Worth knowing
- Small capacity means short runtime in anything power-hungry
- Needs a charger and a power source to refill
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Our review
The eneloop AAA, Panasonic part BK-4MCDE, is the small sibling of the standard eneloop: a minimum 800 mAh at 1.2 V, made in Japan, with the same low self-discharge that keeps about 70% of a charge after ten years. It is the cell for pocket radios, head torches and remotes, and like all rechargeables it depends on a charger being available.
What it is
The distributor data sheet for the BK-4MCDE gives a nickel metal hydride AAA with a minimum capacity of 800 mAh, a nominal 1.2 V, a weight of 13 g and charging from 0°C to 40°C, made in Japan. Older versions of the cell, with the MCCE suffix, were rated at 750 mAh, which is why retailer listings disagree. Panasonic's FAQ gives the storage figure: around 70% of a full charge remains after ten years at 20°C under IEC 61951-2, and the cells ship pre-charged so they work from the packet.
Cycle life is the same story as the AA: up to 2,100 charges under the 2011 IEC test and approximately 600 under the 2017 revision, according to Panasonic. Both are far beyond household use, and a set that is charged a dozen times a year will still be working when the device it powers has been replaced.
Where AAA cells go in a kit
AAA cells run the small things: a pocket radio, an AAA head torch such as the Black Diamond Astro 300 or a Petzl Tikka, a thermometer, a remote. Those devices draw little, so 800 mAh goes a long way, and low self-discharge means a set charged in autumn is still useful in spring. Energizer's technical handbook puts standard NiMH at roughly 50 to 80% of capacity after a year on the shelf; eneloop's advantage is holding far more for far longer.
The dependency is the same as for any rechargeable: a charger and a power source. In an outage that means a USB charger and a power bank. Our power cut preparation guide suggests lithium AAA cells for the sealed kit and eneloops for the devices in daily use.
How it compares
On the rechargeable batteries page the eneloop pro AAA holds about 930 mAh with faster self-discharge and fewer cycles, for high-drain use. Duracell's Recharge Ultra AAA is rated at 900 mAh. The combo pack of four AA and four AAA eneloops is the cheapest way to cover both sizes at once. The eneloop AA is the cell most kit uses; buy AAA only for the devices that take them.
Our verdict
Buy a pack if you have AAA devices in weekly use and a charger. Skip them for the grab bag and for anything you want to leave for years without thought, where lithium AAA cells are the simpler choice. Label the packet with the date you charged them, and top them up twice a year. If you are buying a charger at the same time, pick one that takes both AA and AAA cells and runs from a USB lead, so a power bank can refill it when the mains is off; the four-slot chargers sold with Energizer and Panasonic cells both do this.
A researched review, built from the maker's specs, manual and UK listings; facts checked 2 Nov 2026. Sources: Panasonic eneloop BK-4MCDE AAA data sheet (RS Components, PDF); Panasonic: eneloop FAQ; Energizer: nickel metal hydride handbook and application manual (PDF).
Who shouldn't buy this
Don't buy it if your devices take AA, or you want cells you never need to recharge.
Key specs
| Size | AAA |
| Capacity | 800 mAh |
| Pack | 4 |
| Charger | No |
This is a Researched review: we haven't used this product. We check every specification against at least two independent sources, re-check the UK price on a schedule where we can track it automatically, and say plainly who it isn't for. Commissions never change a rating.
If this isn’t the one
Best for A kit that needs reusable AA cells you can top up once or twice a year and still trust.
as of 2 Nov 2026, 16:07 GMT · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.
Best for A household with both AA and AAA devices that wants one purchase.
as of 2 Nov 2026, 16:07 GMT · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.
Best for Heavier-draw AA devices where runtime per charge matters more than months of shelf life.
as of 2 Nov 2026, 16:07 GMT · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.Questions
What is the capacity of eneloop AAA batteries?
The BK-4MCDE data sheet gives a minimum of 800 mAh at 1.2 V. The older BK-4MCCE was rated at 750 mAh, which explains differing retailer figures.
How long do they hold a charge in storage?
Panasonic says around 70% of a full charge remains after ten years at 20°C. Standard NiMH cells, by Energizer's handbook, keep roughly 50 to 80% after a year.
Can I use them in a head torch rated for alkaline cells?
Usually yes. NiMH cells run at 1.2 V rather than 1.5 V, so some torches show a lower battery level sooner, but most AAA head torches accept them; check the maker's manual.
Do I need a special charger?
Any NiMH charger that takes AAA cells will work. A smart charger that monitors each cell is better for their life than a basic timed charger.
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