Maximize your uConsole's
battery life.

# Edit the boot config
$ sudo nano /boot/config.txt

# Find or add the dtparam for charging current
# Default is usually 500000 (500mA)
# Safe maximum for most 18650 cells: 1500000 (1.5A)
dtparam=axp228-charge-current=1000000

# For aggressive charging with good cells (Samsung/LG/Sony)
# dtparam=axp228-charge-current=1500000

# Reboot to apply
$ sudo reboot

# Check current charging status
$ cat /sys/class/power_supply/axp20x-battery/status
Charging

# Read current charge current limit (in µA)
$ cat /sys/class/power_supply/axp20x-battery/current_max
500000

# Set to 1A (1000000 µA) — if supported by your DT overlay
$ echo 1000000 | sudo tee \
    /sys/class/power_supply/axp20x-battery/current_max

# Verify it took effect
$ cat /sys/class/power_supply/axp20x-battery/current_now

# Check current governor
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
ondemand

# Set conservative governor (all cores)
$ for cpu in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do
    echo "conservative" | sudo tee "$cpu"
  done

# Tune the conservative governor for better battery
$ echo 80 | sudo tee /sys/devices/system/cpu/cpufreq/conservative/up_threshold
$ echo 20 | sudo tee /sys/devices/system/cpu/cpufreq/conservative/down_threshold
$ echo 5 | sudo tee /sys/devices/system/cpu/cpufreq/conservative/freq_step

# Verify
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
conservative

# Install cpufrequtils if not present
$ sudo apt install cpufrequtils

# Set default governor
$ sudo tee /etc/default/cpufrequtils << 'EOF'
GOVERNOR="conservative"
EOF

# Enable the service
$ sudo systemctl enable cpufrequtils

# See available frequencies
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
600000 750000 1000000 1500000

# Cap at 1.0 GHz (CM4) — good balance
$ for cpu in /sys/devices/system/cpu/cpu*/cpufreq/scaling_max_freq; do
    echo "1000000" | sudo tee "$cpu"
  done

# For CM5, cap at 1.5 GHz
$ for cpu in /sys/devices/system/cpu/cpu*/cpufreq/scaling_max_freq; do
    echo "1500000" | sudo tee "$cpu"
  done

# Verify
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq

# Enable WiFi power save immediately
$ sudo iwconfig wlan0 power on

# Make it persistent via NetworkManager
$ sudo tee /etc/NetworkManager/conf.d/wifi-powersave.conf << 'EOF'
[connection]
# 1 = disabled, 2 = disabled, 3 = enabled
wifi.powersave = 3
EOF

# Restart NetworkManager
$ sudo systemctl restart NetworkManager

# Verify
$ iwconfig wlan0 | grep "Power Management"
  Power Management:on

# Check max brightness value
$ cat /sys/class/backlight/*/max_brightness
255

# Set to ~30% (77/255)
$ echo 77 | sudo tee /sys/class/backlight/*/brightness

# Set to ~50% (128/255)
$ echo 128 | sudo tee /sys/class/backlight/*/brightness

# Create a quick-toggle script
$ sudo tee /usr/local/bin/battery-saver << 'SCRIPT'
#!/bin/bash
case "$1" in
  on)  echo 60 | tee /sys/class/backlight/*/brightness ;;
  off) echo 200 | tee /sys/class/backlight/*/brightness ;;
  *)   echo "Usage: battery-saver [on|off]" ;;
esac
SCRIPT
$ sudo chmod +x /usr/local/bin/battery-saver

# Disable Bluetooth
$ sudo rfkill block bluetooth

# Or via config.txt for persistent disable
$ echo "dtoverlay=disable-bt" | sudo tee -a /boot/config.txt

# Disable HDMI output (saves ~25mW on CM4)
$ sudo /opt/vc/bin/tvservice -o  # CM4
# Or for newer kernels:
$ echo 1 | sudo tee /sys/class/drm/card1-HDMI-A-1/enabled 2>/dev/null

# Re-enable when needed
$ sudo rfkill unblock bluetooth
$ sudo /opt/vc/bin/tvservice -p  # CM4

# Check current battery voltage
$ cat /sys/class/power_supply/axp20x-battery/voltage_now
# Value in µV — e.g., 3850000 = 3.85V

# Adjust shutdown threshold in config.txt
$ sudo nano /boot/config.txt

# Add or modify (value in mV):
dtparam=axp228-shutdown-voltage=2900

# Default is 3180 (3.18V)
# Recommended minimum: 2900 (2.9V)
# Absolute minimum: 2700 (2.7V) — risk of cell damage

$ sudo reboot

# Battery voltage (µV)
$ cat /sys/class/power_supply/axp20x-battery/voltage_now
3856000  # = 3.856V

# Charge/discharge current (µA)
$ cat /sys/class/power_supply/axp20x-battery/current_now
-487000  # negative = discharging, 487mA

# Remaining capacity percentage
$ cat /sys/class/power_supply/axp20x-battery/capacity
67

# Charging status
$ cat /sys/class/power_supply/axp20x-battery/status
Discharging

# Battery temperature (0.1°C units)
$ cat /sys/class/power_supply/axp20x-battery/temp
312  # = 31.2°C

# All-in-one status script
$ for f in /sys/class/power_supply/axp20x-battery/*; do
    echo "$(basename $f): $(cat $f 2>/dev/null)"
  done

#!/bin/bash
# uConsole Battery Monitor
# Usage: uconsole-battery-monitor.sh
# Outputs: 🔋 67% | 3.85V | -487mA | ~2h 15m

BAT="/sys/class/power_supply/axp20x-battery"

voltage=$(awk '{printf "%.2f", $1/1000000}' "$BAT/voltage_now")
current=$(awk '{printf "%d", $1/1000}' "$BAT/current_now")
capacity=$(cat "$BAT/capacity")
status=$(cat "$BAT/status")

# Estimate time remaining
if [ "$current" -lt 0 ]; then
  # Discharging: estimate from current draw
  energy_now=$(cat "$BAT/energy_now" 2>/dev/null || echo 0)
  if [ "$energy_now" -gt 0 ] && [ "$current" -lt 0 ]; then
    hours=$(awk -v e="$energy_now" -v c="$current" \
      'BEGIN{t=e/(c*-1); printf "%d", t/1}')
    mins=$(awk -v e="$energy_now" -v c="$current" \
      'BEGIN{t=e/(c*-1)*60; printf "%d", t%60}')
    time_est="~${hours}h ${mins}m"
  else
    time_est="calc..."
  fi
else
  time_est="charging"
fi

# Status icon
icon="🔋"
[ "$capacity" -le 20 ] && icon="🪫"
[ "$status" = "Charging" ] && icon="⚡"

echo "$icon $capacity% | ${voltage}V | ${current}mA | $time_est"

# Install powertop
$ sudo apt install powertop

# Run interactive analysis (let it collect for 30+ seconds)
$ sudo powertop

# Auto-tune all power-saving settings
# WARNING: may cause instability — test carefully
$ sudo powertop --auto-tune

# Generate an HTML report
$ sudo powertop --html=power-report.html
$ xdg-open power-report.html