WHOOP 4.0 Battery Pack and Sensor LEDs
Check how much power your WHOOP 4.0 or battery pack has remaining so you can stay charged wherever your day takes you. Both the WHOOP 4.0 sensor and the 4.0 battery pack make use of LEDs in order to seamlessly and intuitively display the current charge level remaining. See below for a breakdown.
WHOOP 4.0 Sensor LEDs
Double-tap the top of your WHOOP 4.0 sensor and an LED on the side will briefly illuminate. Based on its color, you can quickly tell how charged your 4.0 is:
| Led pattern | WHOOP battery level |
| Green | 50-100% |
| Yellow | 20-49% |
| Red | 5-19% |
| Blinking red | Less than 5% |
Note: If no LEDs illuminate on either side of your WHOOP 4.0 when double-tapping, your 4.0 could have drained to 0%. Open up the WHOOP app and check if your 4.0 has disconnected - you may need to charge.
4.0 Battery Pack LEDs
A fully-charged battery pack has the capacity to charge a 4.0 a single time - for more details on the 4.0 battery pack abilities, check out our 4.0 Battery Pack Overview article.
When plugged in to charge, the LED on your battery pack will remain continuously illuminated. When it's not charging, double-tap the top of your 4.0 battery pack at any time to see its current charge level. Based on its color, you can quickly tell if your battery pack is ready to charge your 4.0.
| Led Pattern | WHOOP battery level |
| Solid green | 70-100% |
| Solid red | 1-69% |