Documentation WARMWORLDBattery life and charging
How to read the per-sock indicator, runtime estimates, and safe charging tips.
Two little battery icons sit at the top of the WARMWORLD app — one per sock. Here's how to read them and what runtime to expect.
Reading the indicator
Each icon shows roughly how much capacity is left in that sock's battery. The colour also changes (green / amber / red) as it drains. Because the left and right batteries deplete independently — they don't share power — it's normal for one to be slightly lower than the other after a long session.
Runtime — what to actually expect
Runtime depends on the temperature you pick and the battery model. Rough numbers from third-party retailers using the same battery spec:
- Low (around 40 °C): 6–8 hours on a full charge
- Medium (around 55 °C): 4–5 hours
- High (65 °C+): 2–3 hours
To get the longest possible runtime: pick the lowest temperature that's actually comfortable, and use the timer so you're not heating during transit / lunch / breaks.
Charging safely
- Use the included USB cable. Generic cables sometimes don't negotiate the right current.
- Charge from a regular 5 V USB port. Fast-chargers don't speed it up.
- A full empty-to-full cycle takes about four hours.
- All four LEDs go solid white when the battery is fully charged.
- Don't try to use the sock while it's plugged into the charger — the battery turns itself off to charge safely, so it won't heat anyway. See Socks disconnect after charging.