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Best rechargeable batteries for a power outage
Flashlights, radios, headlamps and CO alarms eat AA and AAA cells. The right rechargeables hold their charge in a drawer for years and refill from a power bank or power station.
Photo: Sung Jin Cho / Unsplash
By PowerLockdown EditorialUpdated November 1, 20269 min readHow we research
In this guide
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The short answer
The best rechargeable batteries for a power outage are low self-discharge NiMH cells such as Panasonic eneloop, which Panasonic says keep 70% of their charge after 10 years in storage. Pair them with a USB-powered charger so you can refill them from a power bank or power station, and keep a pack of lithium primaries as backup.
The American Red Cross lists extra batteries among the basic supplies for every emergency kit, next to a flashlight and a battery-powered or hand-crank radio. Rechargeables cut the number of cells you have to buy and store. The catch is that ordinary rechargeables drain themselves while they sit. A battery you charged in spring can be flat by the time a hurricane knocks out power in September. That is why storage retention matters more than raw capacity for outage use.
Our picks at a glance
| Pick | Best for | Chemistry | Capacity (AA) | Rated cycles | Storage claim |
|---|---|---|---|---|---|
| Panasonic eneloop AA | Best overall for outage kits | Low self-discharge NiMH, 1.2 V | Up to 2,100 mAh | Up to 2,100 | 70% after 10 years |
| Panasonic eneloop pro AA | High-drain lights and radios | Low self-discharge NiMH, 1.2 V | Up to 2,600 mAh | Up to 500 | 85% after 1 year |
| Energizer Recharge Universal AA | Easy-to-find NiMH | NiMH, 1.2 V | Not stated by maker | Up to 1,000 | Up to 12 months |
| Pale Blue AA USB-C | Charging with no dock | Lithium-ion, 1.5 V | 1,700 mAh (2,550 mWh) | 1,000+ | About 12 months in a device |
| Panasonic BQ-CC87 charger | Charging from USB power | Charger for NiMH AA/AAA | 4 AA in about 4.5 h | n/a | n/a |
| Energizer Ultimate Lithium AA | Long-storage backup | Lithium primary, 1.5 V | Not rechargeable | Single use | Up to 25 years |
The picks
Standard eneloop is the default choice: read the full review. For high-drain gear, see the eneloop pro review. If you want to charge AAs over USB-C with no dock, see the Pale Blue review.
No. 1Rechargeable batteries
Panasonic eneloop AA rechargeable, 8 pack (BK-3MCCA8BA)
Best for: Rechargeables that sit in a drawer for months and still work
- Low self-discharge NiMH; maker: holds 70% of its charge for up to 10 years in storage
- Up to 2,100 mAh (AA); rechargeable up to 2,100 times (maker, IEC test method)
- Factory pre-charged using solar power; low-temperature rating down to -4°F
- 1.2 V nominal; made in Japan
Tradeoffs
- 1.2 V nominal, versus 1.5 V for alkaline; Panasonic's storage figures assume 68°F, and heat shortens them
- Needs a NiMH charger, sold separately
No. 2Rechargeable batteries
Panasonic eneloop pro AA high capacity, 4 pack (BK-3HCCA4BA)
Best for: High-drain gear: headlamps, flashlights and radios run on high
- Up to 2,600 mAh (AA)
- Rechargeable up to 500 times (maker, IEC test method)
- Maker: holds 85% of its charge for up to 1 year
- Low-temperature rating down to -4°F; factory pre-charged using solar power
Tradeoffs
- About a quarter of the cycle life of standard eneloop
- Loses charge in storage faster than standard eneloop
- Panasonic has a newer BK-3HCCE version; check which one the listing ships
No. 3Rechargeable batteries
Energizer Recharge Universal AA, 4 pack (UNH15BP-4)
Best for: A widely stocked NiMH alternative to eneloop
- NiMH, pre-charged
- Maker: can be charged up to 1,000 cycles
- Maker: charge lasts up to 12 months in storage
- Made with recycled battery material (per Energizer)
Tradeoffs
- Energizer's page does not state capacity in mAh
- Storage claim (12 months) is far shorter than eneloop's 10-year figure
- Charger sold separately
No. 4Rechargeable batteries
Pale Blue Earth AA USB-C Rechargeable Lithium-Ion Batteries, 4 pack
Best for: Recharging AAs straight from a power bank or power station USB port, no charger dock
- Lithium-ion, 1.5 V constant output; 1,700 mAh / 2,550 mWh
- Charges in about 90 minutes over USB-C; 1-to-4 USB-A to USB-C cable included; green LED charge indicator
- Rated 1,000+ cycles
- Operating range -4°F to 140°F; certifications listed include IEC 62133 and UN38.3
Tradeoffs
- Maker says a cell left in a device lasts about 12 months, so it is not a 10-year drawer battery
- Each cell needs its own cable lead to charge
- Lower mAh than NiMH on paper (the 1.5 V output closes most of the energy gap)
No. 5Battery charger
Panasonic eneloop Advanced Individual Battery Charger (BQ-CC87ABBA)
Best for: Charging AA and AAA NiMH cells from a power bank, power station or car USB port
- Charges 1 to 4 AA and/or AAA cells individually; powered by the included USB cord
- Maker charge times: 4 AA (2,100 mAh) about 4.5 hours; 2 AA about 2.5 hours; 4 AAA (850 mAh) about 3.5 hours
- 4 LEDs with charge fuel gauge; peak-sensing cut-off stops when cells are full
- Panasonic chart lists USB pass-through charging; ETL certified
Tradeoffs
- Slower than Panasonic's wall-plug CC55 (about 3 hours for 4 AA)
- Built for NiMH eneloop cells, not lithium-ion AAs
No. 6Long-storage batteries
Energizer Ultimate Lithium AA (L91), 4 pack
Best for: Backup cells for a go-bag, car kit or CO alarm drawer that may sit untouched for years
- Maker: AA and AAA last up to 25 years in storage
- Maker: performs from -40°F to 140°F
- Leak-resistant construction; lightweight
- Not rechargeable
Tradeoffs
- Single use: costs more per hour of runtime than rechargeables used often
- Never put them in a battery charger; check the device manual before switching battery types
What matters for outage batteries
Storage retention beats capacity
Outage batteries spend most of their life waiting. Panasonic rates standard eneloop at 70% of charge after 10 years and eneloop pro at 85% after 1 year. Energizer says its Recharge Universal cells hold a charge for up to 12 months. Pale Blue says its lithium-ion AA lasts about 12 months installed in a low-drain device such as a door lock. For a kit you check twice a year, standard eneloop gives the most margin. Panasonic bases its storage figures on 68°F, so a hot garage or attic will drain cells faster.
Capacity and voltage
mAh only compares batteries of the same voltage. NiMH cells run at 1.2 V; alkaline and lithium primaries start at 1.5 V. Multiply to compare energy: an eneloop AA at 2,100 mAh and 1.2 V holds about 2,520 mWh, and Pale Blue lists its 1.5 V cell at 2,550 mWh. On paper they store about the same energy. eneloop pro holds more, at up to 2,600 mAh, but Panasonic rates it for 500 recharges instead of 2,100.
AA rechargeable batteries vs AAA rechargeable batteries
Buy the size your outage gear uses, then standardize. Panasonic lists eneloop AAA at up to 850 mAh and eneloop pro AAA at up to 980 mAh, with the same storage claims as the AA versions. If you can choose, AA gear has the edge: on those figures an AA cell holds more than twice the charge of an AAA.
Rechargeable batteries with charger: pick a USB one
A wall-plug charger is useless when the wall is dead unless you have a power station with AC outlets. A USB-powered charger runs from a power bank, a power station's USB port or a car. Panasonic's chart lists the BQ-CC87 as USB-powered, charging 4 AA cells (2,100 mAh) in about 4.5 hours and 4 AAA cells (850 mAh) in about 3.5 hours. The wall-plug CC55 is faster at about 3 hours for 4 AA. Pale Blue cells skip the dock entirely: each cell has its own USB-C port and charges in about 90 minutes.
Recharging during a power outage: the math
AA cells hold very little energy compared with a power station, so recharging them barely dents a battery bank. One eneloop AA stores about 2.5 Wh. A set of four holds about 10 Wh.
- 01Add up the cells you will cycle: for example 8 AA (2 flashlights, 1 radio) = about 20 Wh of cell energy.
- 02Allow for charger and conversion losses. Our planning assumption (not a maker figure) is to budget about twice the cell energy: 40 Wh.
- 03Compare that with your source. The Goal Zero Venture 35 power bank stores 35.52 Wh, so it refills roughly one set of 8 AA. A 1,000 Wh-class power station such as the Anker SOLIX C1000 could refill that set many times over.
- 04Solar works too: charge the power bank or station from a panel during the day, then run the USB charger from it at night.
Sizing the power station itself is covered in how to get electricity during a power outage and the backup power calculator.
When alkaline or lithium primaries are the better battery for a power outage
Rechargeables win for gear you use every night of an outage. Primaries win for gear that must work the first time after years of storage. Energizer says its Ultimate Lithium AA and AAA cells last up to 25 years in storage and work from -40°F to 140°F. That makes them the better choice for:
- A car kit that bakes in summer and freezes in winter.
- A go-bag you may not open for a year. See best emergency kit for a power outage.
- The spare set for a battery-backup carbon monoxide alarm. See best carbon monoxide alarms and follow the alarm maker's battery instructions.
- A weather radio that lives on a shelf. See best emergency radios.
A simple household setup
| Item | Quantity to plan for | Why |
|---|---|---|
| eneloop AA | Two full sets for every AA device | One set in use, one charging |
| eneloop AAA | Two full sets for every AAA device | Same rotation for headlamps |
| USB charger (BQ-CC87 or similar) | 1 | Runs from a power bank, station or car |
| Energizer Ultimate Lithium AA | One pack per kit | Go-bag, car kit and CO alarm spares |
| Power bank or power station | 1 | Refills phones and batteries |
Pair the batteries with the right lights. Our best emergency lights for a power outage guide and the lanterns and flashlights kit page cover which models take AA cells and which have built-in batteries. The battery operated fan guide covers fans that run on D cells. For the full list, see what to buy before a power outage.
Frequently asked questions
- What is the best battery for a power outage?
- For devices you use every day of an outage, low self-discharge NiMH rechargeables such as Panasonic eneloop, which Panasonic says keep 70% of their charge after 10 years in storage. For gear that sits unused for years, lithium primaries such as Energizer Ultimate Lithium, which Energizer says last up to 25 years in storage.
- Do rechargeable batteries lose charge in storage?
- Yes, all of them do. Low self-discharge NiMH cells lose it slowly: Panasonic rates standard eneloop at 70% after 10 years and eneloop pro at 85% after 1 year. Energizer says Recharge Universal holds a charge for up to 12 months. Top up stored cells when you check your kit.
- Can I charge AA batteries from a power station or power bank?
- Yes, with a USB-powered charger such as Panasonic's BQ-CC87, which Panasonic says charges 4 AA eneloop cells in about 4.5 hours, or with USB-C cells such as Pale Blue that charge directly from a cable. A set of 4 AA cells stores only about 10 Wh, so recharging uses little of a power station's capacity.
- Are eneloop pro batteries better than regular eneloop for emergencies?
- Only for high-drain devices you use often. eneloop pro holds more energy (up to 2,600 mAh) but Panasonic rates it for 500 recharges and 85% retention after 1 year, against 2,100 recharges and 70% after 10 years for standard eneloop. For a kit that sits in storage, standard eneloop is the safer pick.
- Did you test these batteries?
- No. These are research-based picks based on manufacturer specs and published data. We do not test products.
Sources
- Panasonic Energy Corporation of America, eneloop Rechargeable: battery technology, accessed November 1, 2026.
- Panasonic Energy Corporation of America, eneloop pro Rechargeable: battery technology, accessed November 1, 2026.
- Panasonic Energy Corporation of America, Charger Technology comparison chart (CC17, CC55, CC63, CC65, CC75, CC87), accessed November 1, 2026.
- Energizer, Energizer Recharge batteries, accessed November 1, 2026.
- Energizer, Energizer Ultimate Lithium batteries, accessed November 1, 2026.
- Pale Blue Earth, AA USB-C Rechargeable Batteries: technical specifications, accessed November 1, 2026.
- American Red Cross, Survival Kit Supplies, accessed November 1, 2026.
- Ready.gov (FEMA), Build a Kit, updated July 1, 2026.
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