When the power fails, enable your phone’s battery-saving mode first, dim the display, shut down radios and background activity you do not need, and reserve the remaining charge for essential texts and calls. Keep a charged USB power bank ready; use a vehicle charger only outdoors or in a genuinely well-ventilated location.
1. Turn on Low Power Mode or Battery Saver
This is the fastest platform-specific change because it reduces several kinds of background consumption at once.
As an Amazon Associate I earn from qualifying purchases.
iPhone
- On iPhone 14 and earlier, open Settings > Battery > Low Power Mode.
- On iPhone 15 and later, open Settings > Battery > Power Mode > Low Power Mode.
Low Power Mode reduces background activity, lowers display brightness, limits the refresh rate on supported ProMotion models, and pauses some automatic downloads and mail fetching. It turns off automatically when the phone reaches 80% charge. On supported iPhones, Apple’s Adaptive Power setting can also enable Low Power Mode automatically at 20%.
Recommended Free Tools
Android
Open Settings > Battery > Battery Saver. Android’s Battery Saver limits or stops some background activity and can delay visual effects, features, network connections and app activity. Menu names and available controls differ among manufacturers and Android versions, so use the Battery section’s search field if the path is different on your device.
#1 Best Overall
- Huge Capacity 50000mAh Portable Charger - The 50000mAh power bank ultra-high massive capacity will keep your phone and other device running for many days！Without extra worry about low phone battery. Ideal for traveling, camping and hiking.
- Latest PD 22.5W High-Speed Charging - OHOVIV 50000mAh Portable phone charger adopts the latest Super Charger Protocol and Fast Charger Protocol with 22.5W output USB-C port.Support QC4.0 QC3.0 huge capacity power bank with fast charging, it only takes 30 minutes to charge your iPhone 14 from 0% to 55%.（NOTE: The 50000mAh PORTABLE CHARGER ARE NOT ALLOWED ON AIRPLANE！！）
- Power 3 Devices at Once - Cell phone external battery pack is equipped with 2 USB-A (22.5W output) ports, 1 USB-C (18W input/22W output) port and 1, and it can charge three devices at the same time. The portable power bank is universally compatible with all products via USB charging cable, including all iOS and Android smartphones, watch, bluetooth headsets and so on.
- LED Digital Display & Compact Design - OHOVIV 50000mAh Cell phone portable charger comes with smart LED digital display, accurately keep track of remaining juice, allowing you to easily operate your power.Our battery pack charger portable is 13.4*7*3.4cm（5.27*2.75*1.33in）, and weigh 613g (21.6oz), which is easy to carry.
- Safe Powerful Phone Charger - OHOVIV 50000mAh portable charger power bank with premium Li-polymer battery, this portable battery charger can charge your devices multiple times.Battery bank adopt smart chips to prevent overcharge, overvoltage, overcurrent, and short circuit to ensure customer safety.
2. Dim the screen and make it turn off sooner
The display is a continuous, visible drain during an outage. Pull down your phone’s quick settings and move the brightness slider as low as you can comfortably read, or use the display controls in Settings. Then shorten the screen timeout or auto-lock interval so the screen is not left on after every check.
Android documentation specifically recommends both lower brightness and an earlier screen shutoff. The same approach applies to iPhone: avoid raising brightness to compensate for a dark room, and lock the phone immediately after reading or sending a message.
Rank #2
- 40% Smaller & Lighter Portable Charger: Powered by the industry’s first TinyCell high-density battery technology, this ultra-compact 10,000mAh portable charger power bank is 40% smaller and 36% lighter than conventional chargers. Whether you are an office user slipping a mini small portable battery into a purse for commuting, or a student looking for lightweight college essentials, you get powerful daily carry convenience without the extra bulk to keep you powered on the go.
- 45W Pro Speed Portable Phone Charger: This 45W fast charger boosts an iPhone 17 Pro Max to 76%, a Galaxy S25 Ultra to 84%, or an iPad Pro to 60% in just 30 minutes (charging from 20%). Whether you are a driver needing a quick portable charger for car, a commuter relying on a desk phone charger, or a gamer wanting a seamless Switch battery pack and Steam deck charger portable, you will spend less time tethered to a wall and more time enjoying your day.
- Detachable Cable for Multiple Devices: Unlike a standard portable charger with built in cable that becomes useless if the cord breaks, INIU's 0.4ft detachable braided USB-C cable can be swapped anytime to save your investment. It effortlessly transforms into a versatile travel charger for multiple devices, ensuring your family or group travelers always have a reliable portable charger for all cell phones to keep everyone connected without carrying messy cords.
- Airline-Safe Travel Essentials: This TSA-compliant, flight safe power bank provides nearly 2 full charges for your smartphone, making it the perfect battery pack flight safe for business trips, cruise vacations, and airplane travel essentials. Beyond flights, it empowers campers, hikers, and outdoor users with ultimate camping essentials and road trip essentials—so you can explore freely without battery anxiety, making it ideal gifts for travelers women and men.
- Trusted Emergency Backup: As the SAFE Fast Charge Pro trusted by over 38 million users, we ensure the safest charging with the highest-grade materials. When unexpected storms or hurricanes strike, it acts as a lifeline—providing a dependable power outage battery backup and emergency phone charger for emergency users.
3. Disable radios and background drains you do not need
Every active connection can wake the phone, search for a network or transfer data. Turn off only the functions you can safely do without:
Free tools Windows power users keep installed
One-click scans. No signup required.
- Airplane mode: Use it when you do not need mobile connectivity. Turn it off again before trying an emergency call, receiving an alert or sending a message.
- Wi-Fi and Bluetooth: Disable either one when you are not connected to a needed network or accessory.
- Personal hotspot or tethering: Stop sharing the phone’s connection; tethering is a significant drain.
- Location services and GPS: Avoid prolonged navigation or location-heavy apps unless they are necessary for safety.
- Push notifications and background app access: Restrict nonessential apps so they stop waking the phone and checking for updates.
Google warns that tethering, long GPS sessions, streaming and prolonged navigation consume substantial battery. NYC Health likewise advises turning off unused Wi-Fi or Bluetooth, disabling push notifications and background app access, and using the phone primarily for emergency information.
Rank #3
- 【Smaller & Slimmer】A 0.55-inch power bank that breaks the 10000mAh limit, weighing just 219g and only 14mm thick. Enjoy the days’ worth of charging capacity, enough to top up iPhone 16 1.9 times, Samsung S23 1.9 times, or Headphones 11.5 times. The battery pack easily slipped into any travel lover's pockets or bag.
- 【3 Output & 2 Input】2-Pack Portable charger also has 3 USB output ports that detect all the connected devices and efficiently distributes the current. Includes double USB-A (Output), a USB-C (Output&Input), a Micro USB (Input), and USB-C, Micro USB ports can fully refill the battery itself in 4 hrs!
- 【USB C Bidirectional Portable Charger】Designed with USB-C input & output, this power bank brings a great convenience. Use the same USB-C port to recharge the portable charger and power your phone, earbuds, tablet, laptop and other devices. Bidirectional charging saves time and simplifies your carry. Evopow battery pack charger portable— your smart charging solution.
- 【Charge 3 devices simultaneously】10000mAh Power bank can charge a iPhone, a Tablet and a Headphones at the same time. Lets you share battery pack with family and friends anywhere, anytime. Whether you're traveling, commuting, or just getting through a busy day, you'll never have to deal with the "which device do I charge first?" dilemma again.
- 【Your Reliable Blackout Partner】When a sudden power outage hits, panic kicks in—phones die, lose connection, and lights go out. Stay powered! This compact power bank is your emergency must-have—keeping your phone and devices charged when the power goes out. Peace of mind, right in your pocket.
Do not enable airplane mode automatically just because the power is out: emergency alerts and emergency calls may require a network connection. If you need connectivity, leave the relevant radio on and disable the other sources of activity instead.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.4. Reserve the phone for essential communication
After the settings changes, protect the charge you have left. Avoid streaming video, gaming, downloading media, social scrolling and long navigation sessions. Keep necessary voice calls brief and limit non-emergency calls.
Rank #4
- 56,800mAh Portable Charger – Multi-Day Power: Built for extended use, this high-capacity power bank keeps your devices charged for days. Compatible with iPhone 18/17/16/15/14/13 series, Samsung Galaxy S25/S24/S23, Google Pixel 9/8/7, Android phones, iPad, tablets, earbuds, and other USB devices. A practical Travel Essential for camping, road trips, outdoor work, power outages, and emergency backup. Not allowed on airplanes due to battery capacity.
- Triple Device Charging with USB-A & USB-C: This portable charger battery pack features 2 USB-A outputs and one two-way USB-C port, so you can charge up to 3 devices at once without waiting. The smart power bank automatically adjusts current output for stable, efficient charging and helps protect connected devices. Ideal for iPhone, Samsung, Android phones, iPad, tablets, and other USB-powered electronics during road trips, long commutes, business meetings, family outings, or power outages.
- 22.5W PD Fast Charging & 10+ Device Charges: This portable charger delivers fast, stable USB-C charging for iPhone 18/17/16/15, Samsung Galaxy S25/S24, Android phones, tablets, and more. The fast charging power bank charges iPhone 17 to about 60% in around 40 minutes, while the 56,800mAh battery pack powers iPhone 17 or Galaxy S25 10+ times, helping reduce battery anxiety during travel, camping, work, and emergencies.
- LED Display & Multi-Layer Safety Protection: The built-in LED digital display shows the remaining battery percentage clearly, so you can check your portable charger power level at a glance. This high-capacity power bank battery pack is designed with safeguards against overvoltage, overheating, short circuits, and overcurrent, helping deliver safe, stable charging for phones, tablets, earbuds, and other USB-powered devices during daily use, travel, and backup power needs.
- Heavy-Duty Backup Power for Outdoor Use: Built as a reliable external battery, this 56,800mAh portable charger power bank provides long-lasting backup power when outlets are not available. The high-capacity battery pack fits in backpacks, gear bags, or emergency kits, making it useful for road trips, hiking, camping, outdoor work, storms, and power outages. Works with your own USB charging cables for flexible everyday use.
When a message will do, text rather than call. FEMA explains that text messages use less bandwidth and may get through more reliably when networks are crowded; NYC Health’s concise advice is, “Text. Don’t call.” Draft messages before turning connectivity on, send them, then lock the phone again. Keep the phone available for emergency information and updates rather than entertainment.
Do these 3 things before closing this tab:
1Clear out junk files and repair common Windows errors2Fix the driver behind crashes, sound loss and screen glitches3Repair Windows errors before they cause bigger problemsKeep a safe charging backup
FEMA recommends having an emergency charging option for phones and other mobile devices. For most households, a USB power bank is the most broadly useful single backup because it works without a wall outlet and can be carried with the phone. A 12V USB car charger is a useful secondary option if you have access to a vehicle. The U.S. Department of Energy also recommends keeping spare batteries and a car charger.
What to compare when buying a power bank
| Buying axis | Why it matters during an outage |
|---|---|
| Battery capacity | Indicates how much stored energy is available for recharging phones. |
| Expected phone recharges | Helps you match the bank to the number of devices and outage duration. |
| USB-C and USB-A compatibility | Determines whether your existing cables can be used. |
| Size and weight | Affects portability and whether the bank is practical to keep with an emergency kit. |
| Recharge method | Shows how you will refill the bank after its stored energy is used. |
| Safety certifications | Provides a check that the product has undergone relevant electrical-safety testing. |
Official guidance does not establish a universal number of extra hours for any tweak or a guaranteed number of phone recharges from a particular product. Actual results depend on signal strength, phone model, battery health, temperature and what you continue doing on the device.
Charging from a vehicle
If you charge from a running car, follow FCC, FEMA and Department of Energy safety guidance: move the vehicle outdoors or to another genuinely well-ventilated place before running the engine. Never run a vehicle in a garage, even with the door open. Use this option only after any immediate danger has passed and remain alert to carbon-monoxide risk.
Quick Recap
A practical outage sequence
- Enable Low Power Mode or Battery Saver.
- Lower brightness and shorten screen timeout.
- Stop hotspot use, streaming, navigation and other heavy activity.
- Turn off unused Wi-Fi, Bluetooth, location, push notifications and background access.
- Use airplane mode only during periods when you do not need network service.
- Text when possible, keep essential calls short, and lock the phone between tasks.
- Recharge from a charged USB power bank; if using a car, do so only in safe, ventilated conditions.
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 at the time of purchase will apply.
