With constant usage, the batteries last for over 6 days.

The new firmware features some relevant new features.

  • standby mode has been re-enabled; this can give up to 1 month of battery life

  • new battery level indicator

  • new charging indicator

Instructions for updating firmware are found here. Also, please update the phone app to v.1.3.5 for full compatibility.

Standby Mode

Standby mode requires both firmware 0.6.0 and phone app version 1.3.5 to work. Standby mode is off by default and must be enabled via app settings. The basics:

  • when standby mode is enabled, CORE will automatically enter a low power state after it has not been worn for 20 minutes.

  • during standby mode, all data communication is disabled.

  • standby mode can extend the time between recharges to up to 1 month.

You can wake your CORE from standby mode by shaking the CORE, connecting it to a charger, or resetting it.


The LED light now has six functions:

  1. battery level indication

  2. heart rate monitor detected

  3. charging status

  4. the device initially connects to CORE (4x rapid blink as previously)

  5. data is downloaded from CORE (continual fast blinking, as previously)

  6. on reset (short blink followed by battery level indication, as previously).

Shake to wake and battery level indication

When you shake your CORE to wake it from standby, the LED indicates how much battery is left.

LED behaviour


Residual capacity

Operating time left

Standby time left

3x short blink



Less than 12 hours

Less than 1 day

1x longer blink



> 12 hours

1–5 days

2x longer blink



> 36 hours

> 1 week

3x longer blink


>50 %

> 72 hours

> 2 weeks

Heart rate connection

After the battery status is given, the heart rate monitor status is indicated for 2 minutes. In free-living mode (no heart rate monitor detected), CORE will give a single blink every 2 seconds. In sports mode (heart rate monitor detected), it will double blink every 2 seconds.

  • no heart rate monitor detected: single blink every 2 seconds (free-living mode)

  • heart rate monitor connected: double blink every 2 seconds (sports mode)


The LED will also now show charging status while connected to a USB:

  • charging: LED blinks 1s on/1s off

  • charge complete: LED off

  • connect USB: blink 5x

  • disconnect USB: no reaction

The device connects to CORE

Your CORE will blink 4x rapidly when it connects to a device.

Data downloaded from CORE

Your core will continuously blink rapidly while it is downloading data.

On reset

Short blink followed by battery level indication (see “Shake to wake”)

Android App v.1.3.5

This latest app version is needed to enable standby mode. You can find it in the Google Play store.

If the CORE is off (following a reset) and for future firmware updates when CORE is detected to be off-body for a sufficient time, it will automatically sleep.

In this case, under average use (just for sports training and competition only), the expected run-time is about 5-6 weeks on one charge.

Inside the CORE App, a battery level indicator shows the current charge

Once empty, a complete recharge takes about 2 hours.

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