Why does WhatsApp drain so much phone battery? ⁄ Manual do Usuário

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Scarcity makes us pay more attention to details. A clear reflection of living with limited resources, one of the things that has intrigued me is the tiny battery capacity of my phone.

It wasn’t the biggest when it was new and, four years later, reduced to ~82% of its original capacity and more demanded by major annual software updates, it now requires some planning on the days I know I’ll be away from power outlets for long stretches.

It’s not quite a problem because I work from home. Still, sometimes I find myself playing battery babysitter.

My phone’s energy scarcity made me learn more about settings and workarounds to extend its battery life than I would have liked. It also led me to revisit some habits that I carry from my first phones, over twenty years ago.

On iOS, within the phone’s settings, there’s a dedicated battery section. The latest versions display a daily consumption chart, listing the most power-hungry apps and highlighting those that exceed the standard.

This chart is very useful for detecting misbehaving apps and insane apps. The misbehaving ones are put in their place: no background app refresh. It helps.

The insane ones are a different breed. They ignore the ban on updating when not in use. The worst offender is WhatsApp, and maybe it only flies under people’s radar due to the large batteries in modern phones and its reputation as a lightweight app — something it hasn’t been for at least ten years.

It’s hard to give up an app that became synonymous with digital communication, especially in Brazil. What to do to tame it?

Bad, but it can get worse.My default reaction — blocking the app from refreshing in the background — doesn’t work as intended with WhatsApp. Even with this setting enabled and very little active use (“On Screen”), the days went by with Meta’s messaging app frequently at the top of the energy consumption charts, sometimes marked in orange, indicating abnormal consumption.

My theory is that WhatsApp takes advantage of notifications to keep a channel open with Meta’s servers. It’s not a conspiracy theory: in February 2024, researchers discovered that some apps on iOS used notifications to capture data beyond what was necessary for their declared purposes. Unsurprisingly, Meta, WhatsApp’s owner, was among the offenders.

On a given day, WhatsApp was responsible for 20% of my phone’s energy consumption because it spent almost an hour working in the background. Doing what? I don’t know.

What on earth happened here!?The bigger surprise came when I also turned off notifications. This extreme measure means an app doesn’t exist for the operating system until it is opened.

Or so I thought. The battery stats still accused WhatsApp of working in the background. How?!

(This isn’t a new question, by the way. In July 2023, when I suspected Signal was devouring my battery, I mentioned WhatsApp in passing [pt_BR]. In the end, the culprit was indeed WhatsApp.)

I’ve never had the habit of force-closing apps from the multitasking view — double-clicking the iPhone’s home button (or swiping up) and discarding the app window by swiping it upward. Apple itself says this practice is harmless, that the system can manage its resources according to demand.

The only explanation I could come up with is that WhatsApp takes advantage of having been opened to, somehow, keep sucking data and resources when it’s not in the foreground, but still saved in RAM. To test this hypothesis, I started force-closing it after using it.

Today, my WhatsApp is treated like radioactive material. It sends no notifications, doesn’t update in the background. On the rare occasions I need to open it on my phone, I do what I have to do and then force close it.

Tamed, but at what cost?<br>The extra effort has paid off, as seen in the screenshots above. Would I rather not have to do it? Certainly. Replacing my old phone with one newer with a larger battery would solve it by brute force: with more energy available, WhatsApp’s excesses would cause less damage proportionally. It might even go unnoticed. That would be an expensive individual solution to a (possible) collective problem, though.

Obviously, I won’t do that. Not because I’m cheap. I refuse to fix it that way because there’s no plausible reason for a messaging app to demand so much from the phone, nor for me to replace a functional device with a newer, larger battery capacity one.

Alongside these containment measures, I continue trying to communicate with people through other, better-behaved apps. There’s Signal and, even better than that in this regard, the system’s default messaging app, now viable thanks to the arrival of RCS in conversations between Android and iOS.

There is also the possibility that my phone suffers from some very specific and hard-to-replicate bug. iPhone users, what is WhatsApp’s battery consumption like on your phones?

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