Hello Apple Team, I’ll be attending the Battery and Performance Optimization Lab this Thursday, and I’d like to prepare as thoroughly as possible to get the most value from the session. I’m particularly interested in understanding what I can do beforehand to identify optimization opportunities in my app and arrive with useful performance measurements and actionable questions. I would appreciate your guidance on a few areas: Xcode configuration: Are there specific build settings, diagnostic options, profiling configurations, or performance-related settings I should enable or review before the lab? Performance measurement: Which Instruments templates, metrics, or profiling workflows would you recommend using beforehand to establish a meaningful baseline for CPU usage, memory, energy consumption, and battery efficiency? Preparation: What measurements, diagnostic reports, or reproducible test scenarios would be most useful to bring so we can spend more time investigating optimization opportunities rather than establishing a baseline? Technical resources: Are there specific WWDC sessions, documentation, or technical concepts you recommend reviewing to better understand how iOS manages energy consumption, background execution, and performance? Prioritization: What are the most important things developers should understand before attending this lab, particularly when optimizing an application that performs continuous on-device processing and audio playback? iPhone Duo testing: Will the engineering team have iPhone Duo demonstration or development units available during the lab for testing and profiling applications on actual hardware? My app includes Duo-specific multitasking and display adaptations, and I’d particularly value the opportunity to evaluate performance, battery efficiency, and resource usage on the device. My goal is to arrive with a well-profiled application, a clear understanding of its current performance characteristics, and enough preparation to make the session as technically productive as possible. Thank you for your guidance. I’m looking forward to learning from the team on Thursday!

I'm developing an iOS app that includes the following Network Extension providers: NEPacketTunnelProvider NEFilterDataProvider NEFilterControlProvider I want to analyze CPU usage, memory footprint, and battery/energy impact for these extensions after release, using data collected from production devices. I've been looking into MetricKit, including MXMetricManager and MXMetricPayload, and would appreciate clarification on its support for app extensions. Specifically: API support: Can MetricKit be initialized and registered as a subscriber from within a Network Extension provider's process? Are there any restrictions specific to these extension types? Metric availability: If registration is supported, do the resulting metric payloads contain CPU, memory, and energy metrics attributable to the extension itself, or do they cover only the containing app? Production reliability: Can I rely on MetricKit to collect these metrics consistently across production devices and app versions? Are reports generated for extensions independently, and are there known limitations in report delivery or coverage? Memory and CPU: Is there a supported way to obtain the extension's peak memory footprint and CPU consumption through MetricKit? If these metrics aren't available through MetricKit, what APIs or reporting mechanisms does Apple recommend? Energy and battery: Can MetricKit provide energy-impact metrics specifically attributable to a Network Extension provider, rather than aggregated metrics for the containing app? Recommended approach: For post-release analysis of these extensions, should I use MetricKit, Xcode Organizer's Energy reports, custom telemetry within the extension, or a combination of these? My goal is to monitor resource consumption and identify regressions in production without relying on Instruments profiling on individual devices. I'd appreciate clarification on which of these capabilities are officially supported for Network Extension providers and which approach Apple recommends for reliable production monitoring. Thanks!

Hi there! i have a similar issue as this guy (Link), but on my iPhone 14 Pro running iOS 16.4 (20E5229e). Without really using the wallet, it accounts for a huge portion of battery usage (see below). Does anyone of you have a similar issue?

I'm building an accessibility feature where a user walks around and taps NFC tags to trigger updates in the app (e.g., wayfinding/context info). I want a "Live Mode" toggle that keeps the app listening for NFC reads continuously while it's on, processing each tag as it's scanned, rather than one-shot read-and-dismiss. Is there a Core NFC API or session configuration that supports this kind of continuous/persistent listening, or does every read still require invalidating and restarting the session afterward? Currently: I have high-performant reads working reliably with passive NDEF/tag detection. What I'm trying to figure out: Recommended approach — should I keep a single long-lived NFCReaderSession alive and handle repeated reads within it, or restart a new session immediately after each read? VoiceOver / accessibility — how does the system NFC sheet interact with VoiceOver, especially if the session is restarting frequently while the user is mid-walk? Session timeout and restart handling — what's the best way to detect and recover from a session timing out or invalidating unexpectedly, without the user noticing a gap in "Live Mode"? Battery/radio use — are there known concerns with keeping NFC polling active over an extended period (minutes, not seconds)? Thank you.

I recently noticed a UX inconsistency while using the battery charge limit feature on my MacBook with a MagSafe charger. With the optimized charging feature, users can set a custom maximum charging limit (for example, 95%) to improve battery health. However, the MagSafe LED indicator continues to show the charging state (amber) even after the device reaches this user-defined limit. Previously, the LED would turn green when charging reached 100%, clearly indicating a “fully charged” state. But now, when charging stops at a user-defined limit, there is no clear visual feedback that charging has effectively completed based on the user’s preference. This creates confusion, as the LED suggests that charging is still ongoing even though the system has stopped charging at the configured limit. A possible approach to improve this could be to treat the user-defined limit as an effective “fully charged” state during charging. For example: if is_charging: if battery_percentage < user_defined_limit: LED = AMBER else: LED = GREEN This would align the physical LED indicator with the system’s charging behavior and improve clarity for users without requiring hardware changes. Has anyone else observed this behavior, or is there any existing workaround?

Since my questions were never answer and no replies during the group lab, I'm posting them here: When does vapor chamber cooling activate on the new iPhone 17 Pro devices? Does the system handle the cooling in those scenarios, can developer activate it? Does volume level affect performance/battery? Can you discuss bluetooth connections to AirPods Pro 3/AirPods Pro Max and impact on battery? Is there an API to detect thermal changes and what are UI changes that can reduce thermal impact when app is in background and foreground? Whats the best way to profile Power usage and battery drain when an application is processing, working in background and multimodal? Thank you.

Ever since virtualization changed when Apple transitioned to their own Apple silicon chips, I’m curious whether there is anyway to make virtual machines read the host battery? Asking this because VMs in general always assuming it’s on AC adapter makes battery drain a lot faster it seems like so I’m curious whether adding it or some workaround to add battery reporting w/ power efficiency is possible to match with VMs is possible on Apple Silicon so users on Apple silicon MacBooks don’t have to worry about huge battery power consumption drain with adding some sort of feature or pass through to make VMs read host battery. Hope this makes sense.

While analyzing system power on an M4 Max under GPU-heavy compute workloads, I noticed that the the GPU power reported by powermetrics does not come anywhere close to total system DC power reported by the SMC counter PDTR (as used by utilities like mactop). For example, in a heavy GPU workload, powermetrics would report a 65W idle-load delta on the GPU, but at the same time system DC power would rise by 179W, leaving 114W or nearly 2/3 of total system DC power on a Mac Studio M4 Max unexplained. From measurements, the difference appears to correlate with the amount of on-chip data movement (for example, varying bytes-per-FLOP in the workload changes the observed gap). Using SMC and IOReport, I was able to reverse engineer an energy model for the GPU that explains almost all of the energy flow with less than 2% error on the workload I studied. The result is a simple two-term energy roofline model: P_GPU (GPU_combined term in the plot) ≈ a * bytes + b * FLOPs with: ~5 pJ/byte for SRAM movement ~2.7 pJ/FLOP for compute. Has anyone observed similar behavior, or is there guidance on how GPU power reported by IOReport/powermetrics should be interpreted relative to total system power? In particular, I’m interested in whether certain classes of GPU activity may not be attributed to the GPU component in IOReport. Full details with the methodology and results are available here: https://youtu.be/HKxIGgyeISM

My phone says ‘Slow Charger’ even if it’s Apple original power adaptor and cable. It‘s new and i think it’s a software issue. If it is then please fix it. If it’s not i’ll try fixing it myself. And a few things that i don’t like about iOS 26.4 are: Overheating, Safari Bugs, Apple Music UI not working. Please also try to fix them.

iOS 26.2 Beta 23C5044b Phone's battery reports 0% Health, leaving it on multiple chargers (high/low wattage) doesn't change anything. Icon changes to charging. Changed the battery with a high quality aftermarket of ~70% charge, same issue. Unable to remove beta or update to RC2 due to the 20% minimum required... not sure what to do.

Gostaria de propor a criação de um Modo de Bateria Crítica Inteligente para impedir desligamentos abruptos quando o iPhone atinge 1% de bateria. O objetivo principal é evitar perda de dados, especialmente em tarefas importantes ou documentos não salvos. ✔️ Funcionamento sugerido: • Quando o iPhone atinge 1% de bateria, o sistema ativa automaticamente um modo de energia ultrarreduzida, mantendo o aparelho ligado por alguns segundos ou minutos extras. • Esse modo poderia: • suspender animações; • reduzir brilho ao mínimo; • pausar atualizações em segundo plano; • congelar aplicativos não essenciais; • priorizar salvamento automático de arquivos, notas, gravações e mensagens. ✔️ Benefícios: 1. Evita a sensação de desligamento inesperado. 2. Reduz o risco de perda de dados importantes. 3. Melhora a segurança e experiência do usuário. 4. Prolonga a vida útil da bateria, reduzindo ciclos críticos. ✔️ Considerações: O objetivo não é estender artificialmente a autonomia, mas sim criar uma janela de proteção que permita ao sistema salvar dados e fazer desligamento programado, evitando danos e frustração.

Is it recommended to turn off 'Charge Limit' if I leave my iPhone plugged into my Mac all day for development? I want to minimize battery degradation. Thanks

I have bought iphone 16 pro max on October 28, ( 9 months ago) and rarely dropped by battery health below 20%. I also set limit to 80% so I can preserve my Battery Health. I am not a multitasking user. I used fan to keep the phone cool during charging. But today I update to iOS26 public beta, It dropped to 99% at 88 Cycle which is quite low cycle. Many other user are getting their battery health dropped to 99% after 120, 130+ cycle with daily usage. Why mine got dropped after updating. I am quite unhappy with it, and iOS 26 is so jittery in my phone

I am monitoring the battery usage of an app when it is running in the background and foreground. The app uses "Always" location permission, and we're observing 15 hours of background usage and 10 minutes of on-screen usage. The battery usage for our app is showing 44%, while other apps are showing around 14% and so on, representing the cumulative battery percentage. Based on this information, is it normal usage or my app is consuming more battery

A while ago i installed iOS 26 beta 2 on my iPhone 12 mini with an unrecognised battery, and after updating, the battery percentage was stuck at 1%. so I tired different things, but never worked if not downgrading to iOS 18, now iOS 26 is out and i don't know if it now safe to update. i don't have the time now to troubleshoot so if someone can help me or tell me if this bug is fixed

I have a iPhone 16 pro for two months and since have put 26 beta my batTrey is draining much quicker

Hi , since I've been trying out this latest beta, my battery life has dropped dramatically. I have an iPhone 16 Pro. It doesn't last until the evening. I didn't have any problems with version 4 before. Thanks

I Downloaded new beta 7 iOS 26 update and i have issues with my iPhone 15 pro

Hello, when I got it, I updated it, but the battery life has decreased. Please advise. My battery health is 99%. It's been a few months since I bought the phone.

Hello Apple team and community, I’m reporting a critical issue affecting iPhone 13 (128 GB) on iOS 26 Public Beta 3. Problem Summary: • Device stays stuck at 1% battery, even while charging • Battery Health shows 0% in Settings • Phone reboots every 5 minutes while unplugged • Only works when connected to power • Cannot update, charge properly, or maintain uptime Additional Context: • The issue appeared immediately after installing iOS 26 beta 3 • Affected devices often have a replaced battery (even official or high-quality replacements) • Seems to be a software validation bug related to battery firmware • Reported by many users across Reddit, Apple Forums, and Twitter — but not listed in Known Issues What Has Been Tried: • Recovery Mode / Safe charging / Clean install (same version) – no effect • Third-party repair tools (ReiBoot, 3uTools) — partial workaround • Jailbreak with Nugget or iCleaner to disable crash daemons – temporarily helps • Apple Support suggested full device replacement (!) ⸻ Request: Please investigate and acknowledge this issue. This bug renders devices unusable for users with legitimate battery replacements — we need a fix in an upcoming beta.