Planning Devices and Power for a Long Outage

Updated September 2026: in 2018 I continued my account of the first day of the 2015 Chennai floods, when my MacBook Pro ran out of battery around 7pm and took my hotspot, and every connected device, down with it. I have rewritten it into advice on planning devices and power for a long outage.

After shutting my office laptop, I kept browsing on the MacBook Pro in hotspot mode. I had an old Samsung Galaxy phone and an iPod Touch, both charged to 100%. By about 7pm the MacBook Pro was out of battery, and since it was the hotspot, everything else lost the internet. The rain kept pouring. For the first time I went down to the portico to look, saw the rain lashing everywhere, and went back in after a few minutes. I did not know it was the last time my phone would have signal at home.

What went wrong with the setup?

Everything depended on one device with the largest battery drain. When it died, so did the connection for all the others. A phone hotspot would have lasted longer and cost less power per hour.

How should you plan devices for an outage?

• Give each device a role: phone for calls and messages, one device for news, one kept off as reserve.
• Avoid single points of failure: do not route everything through one device.
• Download entertainment and documents early: offline content needs no signal.
• Know where signal is strongest: near a window or on a higher floor.

What happens to mobile networks in a flood?

Towers run on grid power with limited backup. In long, widespread outages, as in Chennai in 2015, the backup runs out and coverage disappears. Expect your signal to fail after a day or so, and send important messages early.

Is it safe to go out and look?

Only within the building and away from water, wires and basements. Floodwater hides open drains and live cables. Staying in was the right choice.

Keep reading

• Seeing Your iPhone Battery From a Mac
• Replacing an Old First-Generation Chromecast
• Moving From Windows To Mac: What Actually Ports