210W Screen-On Extreme Fast Charging Mod

Overview

210W Screen-On Extreme Fast Charging Mod (authored by He Zheng & Class 6 Grade 1) is a comprehensive low-level charging power unlocker designed for Xiaomi, Redmi, and POCO smartphones.

In stock MIUI and HyperOS builds, Xiaomi aggressively throttles fast charging whenever the display screen is turned on—often reducing a 67W or 120W connection down to a sluggish 15W–18W to minimize surface temperatures. This module reconstructs the device thermal engine rules, allowing users to experience full-speed charging while gaming, navigating, or streaming videos.

Technical Architecture & How It Works

The module executes a thorough multi-tier vendor systemless override across kernel modules, user-space daemons, and configuration files:

1. Thermal Engine Replacement & Binary Daemons

The module patches vendor thermal binaries located under /system/vendor/bin/:

• thermal-engine-v2
• mi_thermald
• thermal_manager

These binaries interface with Linux sysfs nodes (/sys/class/power_supply/battery/current_now and /sys/class/qcom-chg/) to modulate charging step currents.

2. Vendor Policy Overrides

The module supplies comprehensive configuration overrides across /system/vendor/etc/:

• thermal-global-u-chg-only.conf
• thermal-global-u-nolimits.conf
• thermal_configs.xml (game engine integration)

Under these customized policies, step-down throttling thresholds during screen illumination are removed, instructing the charge controller to maintain maximum negotiation wattage.

3. Safety Guardrails (80°C Hardware Protection)

Fast charging without OEM throttling demands hardware safeguards. The module implements:

• 80°C Emergency Threshold: If battery temperature sensor telemetry crosses 80°C, the daemon cuts charging current for 10 seconds or switches to trickle charging, ensuring absolute protection against thermal runaway.

Verification & Monitoring

Monitor live charging current and wattage while the screen is awake:

# Query active battery charging metrics
cat /sys/class/power_supply/battery/current_now
cat /sys/class/power_supply/battery/voltage_now

# Calculate real-time charging wattage:
# (current_now [uA] / 1,000,000) * (voltage_now [uV] / 1,000,000) = Watts