# do step counters drain your battery? · Angel Step > Your phone counts steps on a chip built to run all day — the app only reads the number. What costs battery is everything else an app does around it. Canonical: https://angelstep.app/step-counter-battery Language: en Updated: 2026-09-30 Whole site in one file: https://angelstep.app/llms-full.txt This file is the markdown twin of the page at the canonical address above: the same words, without markup. Cite the canonical address, not this file. --- The counting doesn't — because the app isn't the thing counting. Your phone counts steps on a chip built to do nothing else, all day, whether or not you install anything. A step counter reads that number. What costs battery is everything an app does around the number. Angel StepCute Pedometer, Daily StepsFree · In-App Purchases · iPhone Scan with your iPhone camera ### The counting is a hardware job Steps are detected by dedicated low-power motion hardware rather than by any app — Apple introduced it in 2013 as the motion coprocessor, measuring motion even while the phone is asleep. The system keeps a rolling seven days of that history, and it runs with the screen off. This is not an Apple quirk. Platform rules state it as a requirement: a step detector must be implemented in hardware rather than on the main processor, precisely because such sensors are expected to run around the clock and doing it any other way would drain the battery dramatically. Sensor readings are buffered in hardware so the main processor is not woken for each one. So the question changes shape. Nothing you install makes your phone start counting, and nothing you uninstall makes it stop. What differs between step counter apps is not the counting — it is everything else. ### What actually costs battery Roughly in order, and none of it is the step count itself. - The screen. The most expensive part of a phone by a distance. An app you open twenty times a day costs more than one you open twice — which is an odd thing for an app to admit, and true anyway. - GPS. An order of magnitude above the motion sensor. A step counter has no use for it; a route map does. - The network. Every advert shown is a request. Analytics are more requests. Syncing to a server is more again. - Background refresh for an app that keeps its own tally instead of reading the one the phone already has. ### How far apart are the sensors? A study of phone sensors left running continuously measured how long the battery lasted with each one active. Hours of battery with one sensor running continuously, from a study of phone sensor power use. ⚠️ Measured with the main processor polling the sensor. | sensor | battery lasted | | GPS, outdoors | 7.1 h | | GPS, indoors | 11.6 h | | Microphone | 13.6 h | | Bluetooth | 21.0 h | | Accelerometer | 45.9 h | The same study puts it another way: GPS raised the drain nine to thirteen times above an idle phone, while the accelerometer raised it about three times. Read these as the distance between sensors, not as the cost of a step counter. They were measured with the main processor polling the sensor; a hardware step detector is cheaper than that, and by how much has not been published. ### Why a free app with ads can cost more An advert is a network request, and a phone's radio is not cheap. Analytics add their own. An app that shows you three adverts a session is doing more work than one that shows none, and the difference lands on the same battery. No controlled comparison of ad-supported against ad-free step counters has been published, so this is a reason rather than a measurement. What ad-free apps cost in money instead is on what step counter apps actually cost. ### What you can check before installing anything The permission sheet is the honest part of any app. A step counter needs motion, and it may ask to read Health. If one asks for location, it wants something other than your steps — and location is the expensive one. ### Where Angel Step stands Angel Step reads the count Apple Health already holds and keeps no tally of its own, and it never asks for your location — there is no map in it and no route to draw. The widget reads Health by itself, and how often iOS lets it wake is the system's budget rather than ours. What this page will not tell you is how much battery Angel Step uses, or that it uses less than anything else. Nobody has measured that, us included, and a number nobody measured is just a sentence with digits in it. ### Sources - Apple, Core Motion — only the past seven days of pedometer data are stored and available for an app to retrieve. Apple Developer - Apple, iPhone 5s announcement (2013) — the motion coprocessor measures motion continuously, even while the phone is asleep. Apple Newsroom - Platform sensor rules — low-power sensor types, the step detector among them, must be processed in hardware; readings are buffered so the processor is not woken. Android Open Source Project - Sensor power study — battery life with each sensor running continuously. Sensors are Power Hungry (2017) Updated 30 September 2026 no map, no route, no location. Angel Step asks for motion and permission to read Health. That is the whole list.