Hi
just recently I have been noticing a huge increase in the battery usage by Arc.
See attached.
Just wondered if you had any idea?
I am using 3.11.0 on an iPhone 14 plus.
Hi @Dirky!
It’ll be worth tapping on the row in the list, so you can see a breakdown of what the “on screen” time is. It should show you something like “11m on screen - 23h 49m background”.
The more time the app spends in the foreground (ie “on screen”), the more battery it will use. The time in the background uses very little battery, so if there’s no foreground time, the battery usage shown in Settings app will typically be much lower.
Basically Arc is optimised such that it can record continuously in the background for up to 2 days on a single battery charge - it’s super battery efficient. But when you bring the app into the foreground / “on screen”, all bets are off. Building and interacting with the UI is unavoidably energy/battery expensive. The map view uses a lot of energy, due to being graphically and data intensive. The timeline views and other tabs are also energy expensive because they need to load and process large amounts of data. iOS also counts the energy cost of the screen itself towards whichever app is in the foreground at the time, and the screen is the first/second most energy expensive part of the phone (the other being the CPU/GPU, which will be more or less energy expensive than the screen depending on how you’re using the phone at the time).
So basically if the app is in the foreground for a lot of time, and the app is showing as having used a fair bit of battery in the Settings app, that’s normal. However if the screen time is very low (eg under 10 minutes or so), and the energy use is still unusually high, that might indicate a problem.
Though because Arc’s core recording engine hasn’t changed significantly (or barely even at all) in a long time, any temporary weirdness in energy consumption is likely to be just that - a temporary blip. Weird things can happen sometimes, and there’s nothing either of us can really do about it.
One example is the phone might’ve been in an indoor situation where it couldn’t get good cell signal nor see enough wifi hotspots to triangulate your location, and then churned through more energy than usual trying to figure out where you were. Arc does auto adjust for those situations, asking for significantly less location accuracy when it detects that the phone can’t cope, but there’s still some unavoidable extra energy cost in those cases.
There’s a bunch of other transient situations that might lead to a temporary spike in energy consumption, but I won’t bore you with listing them out. Suffice to say, unless it’s an ongoing problem it’s not worth losing sleep over it. It’ll likely just come right on its own, and there wouldn’t have been anything either of us could have done to avoid the temporary higher energy consumption anyway.
Hi - also wanted to report high battery usage that has been going on for a few months. If I don’t plug in my phone at night, the app regularly drains the battery to below 10%. It’s pretty much the only app running during those hours. See screenshot for example.
I’m always connected to Wi-Fi at home, so don’t think the signal is an issue here?
I’ve paid for lifetime subscription, but given this serious effect I’ve been recently contemplating deleting the app.
Hi @pjverde!
Arc App records continuously, which means that as long as it’s running it will be using some small amount of battery. However the recording engine is optimised to be as efficient as possible, such that the app can record continuously on a single battery charge for up to 2 days. That means that if Arc is the only app running on a phone, a full battery charge can last up to 2 days before fully draining.
If you don’t plug the phone in overnight, that’s a bunch of hours of sustained trickle battery drain, that will add up - let’s say 8-9 hours, so about a third of a day, which would equate to about 17% of a full battery charge drained overnight. So for example if your phone’s charge level were at 50% when you went to bed, it might be around 33% by the morning. Edit: I should say 17-33% drain overnight, given different phone models last from 1 to 2 days on a single charge.
If it’s draining faster than around that rate overnight, then something is likely going wrong.
If it’s a problem with Arc, it’ll likely be something to do with location data, eg some combination of weak cell tower signal, limited nearby wifi hotspots, and lack of GPS line of sight coming together to cause the phone to use extra energy to try to determine location. Another possibility is that the phone’s battery is aged and is draining unevenly.
Either way, unfortunately there’s nothing I can do from my end. When the phone is unplugged Arc will do nothing other than its optimised “sleep mode” recording overnight - ie the lowest energy consumption possible. The scheduled background tasks won’t run when the phone isn’t plugged in, so Arc won’t be doing anything else that might drain the battery.
The simple fix however is to plug the phone in overnight 
That also comes with the added benefit of the phone running all its scheduled background tasks overnight - not just Arc’s, but the scheduled tasks of all other installed apps, system apps, and iOS itself. Almost all of those tasks are set to only run when the phone is plugged in and idle, ie overnight when you’re asleep.
Aside: If those tasks don’t get that chance to run when the phone is plugged in and idle overnight, they can create a backlog, which can impact the performance and reliability of apps and the system during the day. So in general you really do want your phone to have that chance overnight to do all its housekeeping. Although if you do leave your phone plugged in and idle for extended periods during the day, that might hopefully compensate for the missed opportunity overnight. But really overnight is your best bet.
One thing I should mention: I keep saying “up to 2 days on a single battery charge”, and I should probably explain how I’m getting that number.
I always have at least two phones running Arc at all times, that go almost everywhere with me - my main phone, and at least one “test device” that stays in my bag wherever I go. Those test devices do basically nothing other than run Arc (and Arc Mini). I open up the apps each morning as my first task of the workday, to check that they’ve recorded correctly and all is well.
The “up to 2 days” value is based on these test devices. It used to be only the “Max” phone models that would get past 1 day and get to 2 days, but in recent phone model generations even the standard “Pro” models have reliably surpassed 1 day (ie more than 24 hours) continuous recording.
Currently my main test device is my old iPhone 11 Pro, which has a dying battery (Battery Health view says 78% capacity and recommends replacing the battery). That 11 Pro will happily survive a full day of travel on a single charge, including airports, airplanes, taxis, etc.