Samsung Galaxy S25 One UI 7 Battery Drain After May 2026 Update

What is the Galaxy S25 One UI 7 Battery Drain?

After the **May 2026 One UI 7 maintenance release (firmware builds ending in BYE3 and BYE5)**, Galaxy S25, S25+, and S25 Ultra owners report battery dropping 15–25% per hour in standby and the device running noticeably warmer than under One UI 6.1. The drain traces to three concurrent regressions: a Samsung Account sync loop that wakes the modem every 90 seconds, a Bixby Routines service (com.samsung.android.app.routines) stuck in a wakelock, and an aggressive Quick Share background scan added in this build.

Affected build numbers are S931USQS3AYE3 / S936USQS3AYE3 / S938USQS3AYE3 (US) and S931BXXS3AYE5 / S936BXXS3AYE5 / S938BXXS3AYE5 (EMEA). Samsung Members threads opened May 18, 2026 confirm the regression; an official hotfix is expected in the June 2026 SMR but workarounds exist now.

When does it occur?

• Battery falls 8–12% overnight in airplane mode (should be under 2%)
• Phone is warm to the touch despite no foreground activity
• Settings → Battery → Usage shows "Samsung Account", "Bixby Routines", or "Quick Share" near the top
• The Always-On Display shows the modem icon active even with no carrier traffic
• After installing the May 2026 security patch (SMR May-2026 Release 1)

Common causes

• com.samsung.android.scs (Samsung Account sync) caught in a re-authentication loop against Samsung's chn.samsungcloudsolution.com endpoint
• Bixby Routines wakelock from a Routine triggered by a deleted Wi-Fi network
• Quick Share background scan running every 30 seconds instead of the intended 5 minutes
• Adaptive Battery model corrupted during the update and over-promoting low-priority apps
• New ML-based "Smart Suggestions" service indexing the gallery without throttling
• Thermal sensor calibration drift causing the CPU to stay in performance state P3 instead of P5
• Google Discover widget on the home screen polling at 1 Hz due to an upstream Play Services bug

Step-by-step fixes

1. Identify the rogue process. Open Settings → Battery → Battery usage → "Show full device usage" → tap the three-dot menu → "Show system apps". Sort by 24h consumption. If Samsung Account, Bixby Routines, Quick Share, or Smart Suggestions is in the top 3, follow the matching fix below.

1. Clear Samsung Account cache and force re-login if Samsung Account is the offender. Settings → Apps → Show system apps → Samsung Account → Storage → Clear cache (do NOT clear data unless you have a recovery email set). Reboot, then sign back in via Settings → Samsung account. This breaks the auth loop in ~85% of cases reported on the Samsung Members forum.

1. Disable Bixby Routines wakelock. Settings → Modes and Routines → Routines tab → tap each active routine → toggle off. Then Settings → Apps → Show system apps → Routines → Force stop → Storage → Clear cache. Re-enable the routines you need one at a time, leaving 24 hours between each to spot the culprit.

1. Reset Quick Share to the throttled scan interval. Settings → Connected devices → Quick Share → tap the three-dot menu → "Reset Quick Share". Then immediately set "Who can share with you" to Contacts only (not Everyone). The Everyone mode is what triggers the 30-second scan in this build.

1. Reset the Adaptive Battery model so it relearns app priorities. Settings → Battery → More battery settings → Adaptive battery → toggle off, wait 10 seconds, toggle on. Then Settings → Apps → see app info → Google Play services → Storage → Manage space → Clear all data. Charge to 100% overnight to seed a clean model.

1. Run the Samsung Members diagnostics to verify thermal calibration. Open Samsung Members → Get help → Interactive checks → run Battery, Temperature, and Performance tests in sequence. If Temperature reports >38°C during the idle test, the calibration drift is real — book a free Samsung service center recalibration under the device warranty.

1. Disable Smart Suggestions and the Discover home screen panel as a temporary measure. Settings → Home screen → Media page → off. Settings → Advanced features → Smart Suggestions → off. Each of these adds ~1.5% per hour drain in the affected builds.

1. Roll back the May 2026 patch if needed. If you must, install the prior build using Samsung Smart Switch in PC mode and the BYD9 firmware downloaded from samsung.com → Support → Software updates. Note this requires a factory reset and will trip the Knox warranty bit — only do this if the drain makes the phone unusable.

If it still doesn't work

If none of the above identifies the drain, the issue may be hardware-side battery aging masked by the One UI 7 update. Dial *#0228# to open Samsung's hidden Battery Status menu and read the ASOC (Absolute State of Charge) value. If ASOC reports below 80%, the battery itself is degraded and a service-center swap is the only fix. For S25 Ultra users specifically, also dial *#0011# to open the modem service menu and confirm "Last call drop" is empty — a known May 2026 modem regression keeps the radio at full power after a dropped call until reboot. Wait for the June 2026 SMR (firmware suffix BYF1 or later) which Samsung's developer relations team confirmed on the EFR forum will ship the full mitigation.