How to keep phones charged in a blackout

The short answer

Your phone is your flashlight, news source, map and link to family. In a long outage its battery will be the first thing you worry about. The plan is simple: use less power, carry stored power, and add a way to make more.

Ready.gov advises planning alternative power, such as a portable charger or power bank, for devices you rely on.

Step 1: Use less power

These settings help right away:

1. Turn on Low Power Mode (iPhone) or Battery Saver (Android).
2. Lower the screen brightness and shorten the screen timeout.
3. Close apps you are not using and turn off background refresh.
4. Turn off Bluetooth and Wi-Fi if you do not need them.
5. Use Airplane Mode when you do not need to be reached. According to the FCC/FEMA tips, a phone in airplane mode stops searching for a signal and saves battery. Switch it off every hour or so to check messages.
6. Put the phone away. Use a lantern, not your phone, for light.

Step 2: Text, do not call

The FCC and FEMA advise using text messages for non-emergencies, because texts to other wireless devices may go through when a call will not, though there may be a delay when the network is busy. They also note that limiting calls saves battery.

Keep calls short. Do not assume a text will always arrive. Have a backup plan, covered in communicate when phones are down.

Step 3: A power bank is your first reserve

A power bank is a battery you can charge a phone from. A 20,000 mAh bank gives a typical phone several full charges, which is often enough for a three-day blackout when you use it wisely. As a rough guide, expect three to four charges; the exact number depends on your phone and the bank.

• Keep it full and in the kit.
• Charge it every three months, because batteries slowly lose charge on the shelf.
• Keep the right cable with it.
• Charge the phone when it is down to about 30 percent rather than waiting until 5 percent.

Step 4: Add sunlight

A folding solar charger turns daylight into a trickle of power. It works best in direct sun, so set it in a south-facing window or outside on a sunny day. Charge the power bank with it, not the phone directly, because clouds make the power uneven.

Test it once before you need it, so you know it works and how long it takes.

Step 5: Larger batteries and the car

A portable power station can charge many phones many times and run other things. See running a fridge on a portable power station.

You can charge from a car with a car charger, but follow these rules.

Do not drive around just to charge a phone unless you also need to travel. Keep fuel for real needs.

A simple blackout charging routine

• Morning: check the weather, check messages once.
• Mid-day: put the solar charger in the sun and plug in the bank.
• Evening: charge phones from the bank and send your check-in texts.
• Overnight: Airplane Mode with the alarm on, if you can.

What to do before the next outage

• Fully charge phones, power banks and tablets when a storm is forecast.
• Download offline maps and your family contact list.
• Write key phone numbers on paper. See the family emergency plan.
• Put a reminder in your calendar to charge your power bank every three months.

Next steps

• Plan the first days: the 72-hour blackout plan.
• Back up your phone: communicate when phones are down.
• See the Blackout Kit.