Staying in Touch with Family During a Power Outage

As covered in the power outage article, a power outage is the single most likely thing to happen during a typhoon in Okinawa. And once an outage drags on, your phone’s battery becomes something you need first for letting people know you’re safe — not for light, and not for browsing.

This is exactly where how you structure your communication pays off. If worried relatives and friends contact you one by one and you reply “I’m fine” each time, you burn through both battery and connectivity. Ten people means ten replies.

There’s just one principle: say it once, to everyone, the same message.

Official services are already built around “choosing a status”

It’s not widely known, but the official safety-check services are designed so that you choose from a fixed set of statuses, rather than write a message.

On NTT DOCOMO’s Disaster Message Board, you choose from the following statuses (multiple selections allowed):

“I’m okay,” “Need Help,” “Safe at home,” “At evacuation area.”

On top of that, you can attach a comment of up to 100 full-width characters (200 half-width characters). Information you register can also be checked from non-DOCOMO phones and computers. The Disaster Message Board is separately operated by each of the four mobile carriers (NTT DOCOMO, KDDI, SoftBank, and Rakuten Mobile).

This is the official version of “once, to everyone.” Instead of replying to each person individually, you set one status, and everyone who’s worried can go check it themselves.

Why it connects more easily than a phone call

The Ministry of Internal Affairs and Communications explains that the Disaster Message Board registers and checks messages over the internet, etc. (data communication) rather than the phone lines (voice communication), which get congested easily — so it stays reachable even when phone lines are jammed.

There’s also a voice-based option, the Disaster Emergency Message Dial (171), which records up to 30 seconds per message. How many messages you can record and how long they’re kept can vary by how the service is operated, so check the official guidance when you actually use it. Detailed steps for using 171 are in the island article (Japanese only).

But it may not be activated during a typhoon

This is the single most important thing to know about living in Okinawa.

These services are not always available. They’re activated when a disaster occurs, and their activation criteria are written around earthquakes.

During a typhoon power outage, there’s no guarantee these will be in a usable state. Regarding 171, NTT East states that whether the service starts is “determined by NTT East depending on the situation, and announced to the public via TV, radio, NTT East’s website, and other channels.” In other words, you can’t know whether it’s active without checking an announcement.

Even if your family has agreed “if something happens, we’ll use 171,” it may simply not be activated on the day of a typhoon — and not knowing this is dangerous if you’re relying on it as your only option.

Check whether it has been activated, during a typhoon’s approach, via TV, radio, or each provider’s official website. If it has been activated, it’s the most reliable method available.

So typhoon communication runs on “family rules” instead

What works regardless of whether an official service activates is only the rule you agreed on beforehand, during ordinary times.

Decide these in advance

• Contact once a day, at a set time (for example, 8 a.m. and 8 p.m.). If the rule is “call if something happens,” you both end up waiting on a phone that never rings
• Designate one contact person. For relatives outside the prefecture, that one person relays information to everyone else, and the others check with that person instead — the person actually affected doesn’t have to explain things over and over
• Agree in advance that no reply doesn’t automatically mean something’s wrong. It’s completely normal, during an outage, for someone to simply have their phone turned off to save battery
• Decide on a place to meet up. This is your insurance for when you truly can’t reach each other

Of these, designating one contact person does the most to save battery.

The trick of using your profile to say it “all at once”

Among families who use social media, a known technique is to rewrite your account name or profile to say “I’m okay,” turning your status itself into the message. Whoever sees it doesn’t need to ask, which cuts down the number of exchanges.

That said, this is not an officially recommended method. No description recommending this technique appears in official information from the Ministry of Internal Affairs and Communications, the Fire and Disaster Management Agency, or the mobile carriers. Understand it as a workaround shared among users, not an official one.

If you use it, keep these points in mind:

• It backfires if people can’t tell whose account it is. Rather than replacing your name entirely, it’s safer to add to it while keeping your original name
• On a public account, don’t write anything that reveals your location. “I’m okay” is enough — don’t write your address or that you’re currently out
• It’s meaningless if nobody notices you changed it. Tell your family, during ordinary times, “check my profile for my status”
• Don’t forget to update it. Leaving “I’m okay” up after the situation has changed is more dangerous than writing nothing at all

Separately, LINE has an official safety-check feature, LINE Safety Check, which is exactly this idea turned into a product. When you choose and make public either “I’m okay” or “Affected,” a safety-status badge appears on your profile icon, and your status and message appear on your profile page. It stops displaying once the disaster has settled down. This, too, only appears for large-scale disasters such as seismic intensity 6 or greater, so it won’t appear for a typhoon — but for an earthquake or tsunami, it’s more reliable than a DIY workaround.

Save your battery for staying in touch

Once you’ve decided how you’ll communicate, the next thing is battery. Preparing power banks and portable power stations is covered in the power outage article. Here, we’ll just add how to use what you have once the outage starts.

• Create stretches of time with no communication. If you’ve set fixed check-in times, you can put your phone in airplane mode the rest of the time
• Dim your screen. The screen uses a lot of battery
• Cut back on scrolling through video, maps, or social media. Checking official primary sources briefly uses less battery than browsing

Carriers have also built in power-saving features. DOCOMO’s Emergency Power-Saving Mode is “a mode that, during an emergency such as a disaster, limits your smartphone’s functions to the minimum necessary to extend standby time as much as possible,” keeping apps useful in a disaster available while restricting running apps and background data while the screen is off.

That said, DOCOMO states: “For devices released from the 2020–2021 winter/spring models onward, this feature is not included, with the exception of some models.” Assume it’s not available on a recent device. In that case, use whatever power-saving settings come standard on your device.

What to do during ordinary times

The Disaster Message Board and 171 both offer trial periods. According to the Ministry of Internal Affairs and Communications and DOCOMO, you can try them on the 1st and 15th of every month, among other dates (the three days around New Year’s, Disaster Prevention Week, August 30–September 5, and Disaster Prevention and Volunteer Week, January 15–21).

A method you’ve never once used won’t work when it counts, either. As a check before typhoon season, we recommend trying it out with your family once, alongside registering for power outage information.

What this article does not cover

Whether a safety-check service is currently activated is not covered by this site. Check its activation status via TV, radio, or each provider’s official information.

Each service’s specifications (the wording of status options, character limits, retention period, supported devices) are subject to change. Always check the provider’s official page when you actually use it.