Hold your iPhone to your battery tester. Batteryism reads the values, follows your battery’s health over time and helps you see when it may be time for a new one.
Opens your mail app · only used for the launch email
Coming soon to the App Store · Free · iOS 17+
Clamp your tester on as usual and run the battery test.
Point it at the tester’s screen. Each value fills in as it is read – show the next page for the rest.
Every test lands in your battery’s history. Tap any value to correct it.
One test tells you how your battery is doing today.
Batteryism shows how it’s changing.
Year 1
Example data · scroll to follow one battery
The chart
Health, starting power, charge, voltage and resistance over time – and a forecast of when it may need replacing.
Insights
Worked out on your iPhone: how much cold weather costs, rising resistance, and cranking power against the rating.
Garage
Every battery filled to its health, with a badge when it’s time to test or charge.
Reminders
A nudge when a battery is due for a test, and every four weeks for a vehicle in storage. Swipe for Later or Clear.
Battery label
Hold the camera to the battery’s label – brand, model, capacity and cold cranking fill in by themselves.
Statistics
Health and ageing across every battery you own – and, if you like, how the same model does for others.
Works with Siri – just ask How is my battery in Batteryism?
Always private
Cars, registration plates, VINs, names and notes stay on your iPhone and in your own iCloud. No account, no ads, no tracking.
Shared – if you want
Share your battery readings anonymously and see how your battery model really ages in other cars. Turn it off, and everything you shared is removed.
Opens your mail app · only used for the launch email