> ## Documentation Index
> Fetch the complete documentation index at: https://docs.researchanddesire.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Battery and Power
> Battery monitoring, charging, and power management for RADR
This guide covers RADR's battery system, charging, and power management features.
## Battery System
RADR uses a lithium battery with intelligent monitoring:
| Component | Description |
| ------------------ | ---------------------- |
| Battery Type | Lithium Polymer (LiPo) |
| Fuel Gauge IC | MAX17048 |
| Charging Port | USB-C |
| Charging Indicator | Hardware LED |
### MAX17048 Fuel Gauge
The MAX17048 is a precision fuel gauge that provides:
* **Battery Percentage** — Accurate state-of-charge reading (0–100%)
* **Battery Voltage** — Real-time voltage measurement
* **Low Battery Alerts** — Programmable threshold notifications
The fuel gauge uses proprietary algorithms to accurately estimate remaining battery life, compensating for factors like temperature and discharge rate.
## Battery Indicator
The battery status is displayed in the status bar at the top of the screen:
| Level | Approximate Range |
| -------- | ----------------- |
| Full | 90–100% |
| High | 60–89% |
| Medium | 30–59% |
| Low | 10–29% |
| Critical | 0–9% |
When battery reaches critical levels, save your session and charge RADR to avoid unexpected shutdown.
## Charging
### USB-C Charging
RADR charges via the USB-C port located at the top of the device, next to the power switch.
* Connect any standard USB-C cable
* Compatible with USB chargers, power banks, and computer USB ports
* Charging works while RADR is powered on or off
### Charging Indicator
A hardware LED indicates charging status:
| LED State | Meaning |
| --------- | ------------------------------ |
| LED On | Charging in progress |
| LED Off | Fully charged or not connected |
The charging LED is separate from RADR's software-controlled RGB LEDs. It's controlled directly by the charging circuit.
RADR relies on the hardware charging LED rather than software-based charging detection. This provides more accurate and reliable charging status indication.
### Charging Tips
For fastest charging, use a USB charger rated for 5V/1A or higher.
You can use RADR while charging, but charging may take longer during active use.
## Power States
RADR has several power states:
### Active (Connected)
* Display on, backlight active
* Bluetooth connected to a device
* LEDs active
* Highest power consumption
### Active (Idle)
* Display on, backlight active
* Bluetooth scanning or in menu
* LEDs in idle pattern
* Medium power consumption
### Sleep Mode
* Display off, backlight off
* Bluetooth disabled
* LEDs off
* Very low power consumption
* GPIO wake enabled
### Power Off
* All systems off
* No power consumption
* Requires power switch to wake
## Deep Sleep Mode
Deep sleep provides significant power savings when you're not using RADR but want quick access later.
Technically, RADR uses "light sleep" mode internally rather than true deep sleep. This provides more reliable button wake-up while still achieving very low power consumption. The user experience is the same—the device appears off until a button is pressed.
### Entering Sleep Mode
1. From the main menu, select **Sleep**
2. RADR performs the shutdown sequence:
* Disconnects any connected devices
* Plays the shutdown buzzer sound
* Turns off the display backlight
* Clears all LEDs
* Enters deep sleep
### Wake Sources
The following buttons can wake RADR from deep sleep:
| Button | GPIO |
| ------------------- | ------- |
| Under-Screen Center | GPIO 39 |
| Under-Screen Left | GPIO 38 |
| Under-Screen Right | GPIO 40 |
Press any of these buttons to wake RADR. The device performs a full restart.
### Sleep vs Power Off
| Feature | Sleep Mode | Power Off |
| ----------------- | ---------------- | ------------ |
| Power consumption | Very low | None |
| Wake time | \~2 seconds | \~5 seconds |
| Wake method | Button press | Power switch |
| State preserved | No | No |
| Use case | Between sessions | Storage |
Use sleep mode during sessions with breaks. Use the power switch for extended storage.
## Power Management Tips
### Maximizing Battery Life
1. **Use sleep mode** — When taking breaks, put RADR to sleep instead of leaving it idle
2. **Lower brightness** — The display backlight is a significant power consumer
3. **Disconnect when done** — Active Bluetooth connections use more power
4. **Power off for storage** — Use the physical switch for extended storage
### Monitoring Battery Health
* Check battery percentage periodically in the status bar
* Charge before sessions to avoid mid-session interruptions
* Don't let the battery fully deplete frequently
### Charging Best Practices
* Use quality USB-C cables
* Charge in moderate temperatures (avoid extreme heat/cold)
* Any standard USB charger works (5V)
* Fully charge before first use
## Specifications
| Parameter | Value |
| ------------------ | ------------------ |
| Operating Voltage | 3.3V (regulated) |
| Charging Voltage | 5V USB |
| Deep Sleep Current | \< 100μA |
| Active Current | Varies by activity |
## Troubleshooting
* The fuel gauge may need calibration after extended storage
* Fully charge, then fully discharge once to recalibrate
* Battery readings stabilize after a few charge cycles
* Try a different USB-C cable
* Try a different USB power source
* Ensure the USB-C port is clean and undamaged
* Check that the charging LED illuminates when connected
* Check if you're leaving RADR in active/idle state
* Use sleep mode when not actively controlling a device
* Active Bluetooth connections consume more power
* Older batteries may have reduced capacity
* Press and hold an under-screen button for 2-3 seconds
* Try the power switch if buttons don't respond
* Ensure the battery isn't completely depleted