How to keep your phone charged and useful in a natural disaster

The remnants of Hurricane Ida unloaded a historic deluge in New York City and the surrounding area on Wednesday night, triggering states of emergencies in New York and New Jersey and leading to at least nine deaths. Nearly 1 million households are still without power in Louisiana after Ida made landfall as a Category 4 hurricane on Sunday and the heavy rain knocked down cell towers, leaving many without a phone connection. In California, record-setting wildfires are encroaching on populated areas, including South Lake Tahoe where more than 20,000 people have been ordered to evacuate.

If you're preparing for, in the midst of, or recovering from a disaster, here are some of the best ways you can get your phone in the best shape to help you. From making a charge last as long as possible, to finding the right information online.

- Make your battery last

Assume your electricity can go out at any time and plan accordingly. Charge your phone and any additional devices ahead of time, leaving them plugged in until the last minute. Also charge any backup batteries and laptops, then make sure all charging cords are collected in one place to take with you.

If the power is out, or if you're no longer someplace with an outlet, you'll need to make any charges last as long as possible. To do that, follow these instructions:

Turn on low power mode on your phone if it's an option. On iPhones, go to Settings, Battery, and toggle on Low Power Mode so it's green. On many Android phones, you can swipe down from top of the screen to see your notifications, and swipe down one more time to find a shortcut to the phone's battery saver mode. Meanwhile, some recent Samsung phones offer even more aggressive ways to preserve battery life: Go to Settings, then Battery and Device Care, Battery, and finally Power Saving mode to tweak these options as needed.

Avoid draining activities. Don't use your phone as a WiFi hotspot for other people, don't watch streaming videos and close any apps running in the background that might be using location. Turn off notifications you don't need. If you're in a safe place, you can turn off GPS to stretch the battery life.

WiFi is less draining than cellular connections, so use it whenever possible. If you don't need to be in immediate contact with anyone, you can even turn on Airplane mode for maximum power saving. (Unless you're planning on leaving your phone off for a long period of time, it's better not to turn it off completely.)

Turn off Background App Refresh on iPhones. Go to Settings, General, Background App Refresh. If you have an Android phone, search in your settings for a feature called Data Saver and turn it on - it will prevent all apps except the ones you've selected from sending or receiving data in the background.

Avoid phone calls, and especially video calls, in favor of texts when possible.

Turn down your screen's brightness.

- Different ways to recharge your phone

Again, external batteries are the best to have. But in a pinch, you do have other options for recharging a device when the power is out.

You can charge off a laptop if you have one. This is a good reason to charge your computers as well, even if you don't plan on using them.

If there's an emergency hand-crank radio nearby, check to see if it has a USB port. You can plug your phone charger in here, but be prepared to crank for a long time.

If there's a car available, you can connect through a USB port, whether it's built in or through a lighter-port attachment. You can charge in many (but not all) cars by just turning them on to accessory mode - meaning you just turn the key once to fire up the radio but not the engine. Do not attempt to start the car if it's in deep flooding or a closed space like a garage. If you're going to need the vehicle to evacuate, be careful not to drain its battery on a phone.

- Contact 911 or other assistance

If you need emergency services and have a cellular or Internet connection, always start by calling 911. However, it can be hard to get through - in New Orleans, the 911 system crashed during Ida - and it's best to try all options.

Many counties have added the ability to text 911. Only try this after, and in addition to, calling emergency services. When you text, include your name, a description of the emergency and an address. Look out for a bounce-back message to tell you if your local 911 doesn't accept texts. If it does go through, don't assume it was seen immediately.

Use your phone's SOS service. Android and iOS both have built-in emergency options that will contact authorities. They also can be set up to send your current location to predetermined emergency contacts. It can vary depending on your device, so find out how it works ahead of time.

If authorities can't reach you in time, your best bet might be your community or local help networks. For example, the Cajun Navy is a network of volunteers using boats and other equipment to help rescue people after floods and hurricanes in the South. They have a form on their website people can fill out to request a rescue.

- Share your location with friends

Your friends and family will want to know you are safe and your location in case you aren't safe.

Send your location with everyone over text, so they'll know where to look if you lose contact. Make sure to include people outside of the disaster zone. If you are using a GPS location-sharing option, like the one in iPhone Messages, don't just send your current spot one time. Select the option to share it indefinitely. You can turn this off later.

On an iPhone, you can also open the Find My app, select Friends and add people to share your location with. You can share your live location with others through Google Maps, though there are some limitations.

If you're on social media and have service, drop a line to let people know you're okay. Facebook will let you mark yourself as safe if you're in the area of a disaster. Start on the company's Crisis Response page, where you can also find other calls for and offers of help.

- Get the latest emergency updates

To make sure you have the very latest information, including evacuation instructions, there are a few steps you can take before and during a disaster.

Sign up for all local emergency alerts. While some text alerts can be sent to all phones, many are only sent to people who have opted in. These services are set up by your local governments and use tools like Nixle. Go to your local emergency preparedness website (for example, New Orleans's is ready.nola.gov) and follow directions. Usually you will be asked to text something to a specific number.

Download any emergency apps, such as FEMA's, ahead of time. If you're already dealing with limited service and battery life, stick to their websites.

Follow relevant emergency and informational accounts on Twitter and Facebook. This can include your local fire and police departments, the mayor and governor's office, the state and federal emergency services offices, your local FEMA region, your local National Weather Service account, your state department of transportation, and the state and local fire services. Follow the Twitter hashtag for your disaster, but screen any information you find. Look out for any scams - nobody should call and ask you for money to assist you.

- Keep phones dry and at the right temperature

Most modern phones are sturdy but sensitive to their environments. To make sure they continue working efficiently, take these precautions.

Many phones are now rated as "water resistant." However, you should still avoid exposing them to water as much as possible. If you are dealing with flooding and rain, pop them into a plastic zip-top bag. If you're dealing with a fire, pack them with something cool.

In a storm or hurricane, it's unlikely that you'll be able to keep your phone dry indefinitely. If your phone does get drenched, wipe it down with a dry cloth, gently shake out any excess water and remove the battery if possible. In the event that you have access to a hair dryer with a cooling function, or a working car heater, you can use them to dry the area around your phone's charging port.

Extreme cold and heat can cause your phone battery to be less efficient and even stop your phone from working. You'll typically see a warning sign on the screen if this happens. If you can turn it off, don't turn it back on until it's back to an acceptable temperature. Whether it's extreme cold or heat, avoid leaving your phone exposed and don't leave it in a car.

- Get apps that work when cell service is spotty

If you're struggling to find reliable Internet and cellular connections, there are apps that could still help you stay in touch or give you helpful information. Download and set them up early as part of your disaster preparation, when you have plenty of bandwidth.

Zello: It's a free messaging app for Android and iOS that lets people create and join group "channels" where they can send voice messages and images to many others at once. (Think of it as a free, smartphone-based walkie-talkie.) Multiple volunteer groups have used Zello to organize relief and assistance efforts during hurricanes, but there's one catch: the app cannot be used at all if you don't have an Internet connection.

Google Maps: Download the Google Maps information for surrounding areas in case you need to move fast and cell service isn't available. Put in your main location, hit the three dots in the corner, select Download Offline Map. You can crop the exact area you think you'll need.