With constant usage the batteries last for over 6 days.
The current firmware version means that CORE does not sleep so it should be recharged ahead of time.
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.