OP-1 - how long does the battery last? March 24, 2021 20:43 Updated the OP-1 battery will last about 8-10 hours of constant use, on a full charge. in standby mode the battery will last about 16 hours. Related articles can i purchase a replacement battery from teenage engineering? OP-1 - how do i charge it? OP-1 - how do i calibrate the battery indicator? OP-1 - what is the maximum charging current with which OP-1 should be charged at 5V? OP–1 - how do i update the firmware?