Batteries, rechargeables and chargers for emergencies: what to choose and how to store them (2026)
Which batteries are worth it for an emergency kit: alkaline, lithium or low self-discharge NiMH rechargeables. Plus power banks and USB-C and car chargers. Shelf life, storage and how to use them in a long outage.
In short
- For long-term storage, lithium AA/AAA batteries are best: 10–20 years of shelf life and good cold performance.
- For frequent use, low self-discharge NiMH rechargeables are cheapest: they recharge hundreds of times.
- A 10,000–20,000 mAh power bank charges a phone 2–5 times. Store it at 50–80% and check it every 3 months.
- Standardize: choose flashlights, radios and lanterns that use the same battery size, ideally AA.
Almost everything you use in a power cut runs on batteries: flashlights, radio, lanterns, phone. If the batteries are flat, expired or the wrong size, the gear won’t help you. A simple battery strategy solves that.
Battery types compared
| Type | Shelf life | Rechargeable | In the cold | Best for |
|---|---|---|---|---|
| Alkaline | 5–10 years | No | Poor | Remotes, low-drain devices |
| Lithium (AA/AAA) | 15–20 years | No | Excellent | Emergency kit, car, go bag |
| Low self-discharge NiMH | Holds much of its charge for years | Yes, hundreds of times | Good | Frequently used lights and radios |
| Standard NiMH | Self-discharges in months | Yes | Good | Daily use |
| Built-in lithium-ion | Slow self-discharge | Yes | Poor below freezing | Rechargeable lights, power banks |
The simple strategy
- Standardize on AA (and AAA if needed). Choose flashlights, radios and lanterns that take the same batteries.
- For your emergency kit and car: lithium batteries, which last for years and don’t leak.
- For frequent use: low self-discharge NiMH rechargeables and a good charger.
- For phones: a power bank for each adult.
- For long outages: a power station or solar panel to recharge batteries and power banks.
Power banks
- Real capacity: about 60–70% of the stated mAh reaches your phone. A 10,000 mAh bank charges a typical phone 2–3 times.
- USB-C Power Delivery: fast-charges new phones and, at higher wattages, laptops.
- Storage: at 50–80%, at room temperature. Check and top up every 3 months.
- Don’t leave it in a car in summer heat or deep cold.
Chargers
- A multi-port USB-C wall charger.
- A USB-C car charger: your car becomes a small generator in an outage.
- A NiMH charger that runs from USB, so you can power it from a power bank or panel.
- Spare cables for every phone in the house.
How to store them
- In original packaging or a plastic box, dry, at room temperature.
- Not in the fridge (moisture does more harm than good).
- Away from metal objects (keys, coins) to avoid short circuits.
- Date the box and use the oldest first.
- Remove alkalines from devices you’re not using.
How many you need
- Spare batteries for every flashlight, lantern and radio, for at least 3 nights
- A 10,000–20,000 mAh power bank for each adult
- Cables for every phone
- A car charger
See also headlamps and lanterns and emergency radios.
Recommended equipment
What to look for when buying. Links go to partner shops; if you buy through them we may earn a small commission at no extra cost to you.Details.
Lithium AA batteries
For long-term storage and cold: go bag, car, bedside flashlight.
- Stated shelf life of 15–20 years
- Works below –4 °F (–20 °C)
- Leak-proof
Low self-discharge NiMH AA rechargeables
For devices you use often. Recharge hundreds of times.
- Marked "low self-discharge" or "pre-charged"
- At least 1,900–2,000 mAh
- Smart charger with auto shut-off
20,000 mAh USB-C PD power bank
Charges phones several times, some laptops too.
- USB-C Power Delivery, at least 20 W
- Charge level display
- Safety certified (UL or CE)
USB-C car charger
Charge phones from the car during a long outage.
- At least one USB-C PD port
- 30 W or more total
Frequently asked questions
Why AA rather than other sizes?
AA is the most common size: sold everywhere and used by most flashlights, radios and lanterns. If all your devices take AA, you need only one kind of spare and can swap batteries between devices.
How big should my power bank be?
For one person over 2–3 days, 10,000–20,000 mAh. Only about 60–70% of the stated capacity reaches your phone. For flights, power banks over 100 Wh (about 27,000 mAh) are restricted.
Can I leave alkaline batteries in a flashlight?
Better not, if you won't use it for months. Old alkalines can leak and ruin the contacts. Keep them packaged next to the flashlight, or use lithium batteries, which don't leak.
Sources and further reading
Preper is for general education and does not replace instructions from your local authorities or advice from a doctor. In an emergency, call your local emergency number.