Nothing lives forever — and that includes your phone battery. Not only is it dying small deaths on an almost daily basis, but it’s also dying a longer, slower death that’ll eventually render your phone unusable if it’s not permanently attached to a power source.

Unless, of course, you swap out your old battery for a new one.

You may have a sense that your battery is degrading over time, but not know at what point to replace it. A new app from online community, advocacy group and parts retailer iFixit is here to help. The app includes a battery health predictor that shows where your battery is in its lifecycle and estimates when it’s time to break out the toolkit and give your device a new lease on life.

Repairing our tech rather than simply replacing it when it breaks can save us money in the long run and reduce our contributions to the ever-increasing mountains of electronic waste piling up around the world. And thanks to work of the «right to repair» movement, it’s easier than ever to get hold of the spare parts and guidance we need to fix our tech at home. Still, it can be an intimidating prospect for anyone unfamiliar with the inner workings of their devices.

«It’s never been easier to fix our own stuff, but learning how can be a bit bewildering,» says Kyle Wiens, CEO of iFixit. «We have so many different kind of gadgets in our lives now, how do you learn to fix it all?» The answer is the iFixit app, which comes with an AI helper «Fixbot» to walk you through any repairs you want to make, with access to iFixit’s full catalog of repair guides.

This isn’t the first time iFixit has had its own app, but back in 2015, Apple stripped it from the App Store after iFixit conducted an unfavorable teardown of the Apple TV. Now it’s back, and available on both the App Store and Google Play Store for iPhone and Android phone owners. I took it for a spin.

Predicting the death of my iPhone

My current phone is an iPhone 15 Pro Max. I’ve been using it for just over a year. In that time, I’ve definitely noticed it running out of juice more often, and I was keen to find out when I might need to replace it.

The battery health feature in the iFixit app is still in beta, and the process for getting a reading is slightly different depending on your phone manufacturer. (Spoiler: None are completely straightforward.)

Apple doesn’t currently allow access to battery stats via any of its APIs (iFixit tells me the APIs are there, but Apple won’t approve your app if you use them), so instead you have to ensure you have your phone analytics turned on and then import an analytics file into the app.

If that sounds complicated, be assured that it’s not. In the app is a guide that tells you exactly what to do and I found it easy to follow. I turned my analytics on in Settings and allowed it to gather data for one day before sharing the file with iFixit.

What I found surprised me. I consider myself a power user (my screen time is honestly embarrassing), yet in the year or so I’ve had this iPhone, I’ve completed only 266 full charging cycles. As a result, iFixit rated my battery health as «fair» and says it can now charge to just 86% of its original capacity.

It did add: «Your capacity is declining. Plan a replacement soon to maintain performance.» It turns out that «soon» is a relative term, though, as it recommended that replacement didn’t actually need to happen until February 2027.

I was pleasantly surprised by how much life this iPhone still has in it. It’s entirely possible I’ll replace the battery before then, simply because I like to get a full day of life out of one charge, and that isn’t happening right now. But after CNET editor-at-large Andrew Lanxon replaced his own iPhone battery last month, I feel confident in my ability to undertake open-heart surgery on my phone at home. Plus, I always have iFixit’s Fixbot on hand to help me out if I do get stuck.