Unfortunately sometimes the power fails during unattended logging measurements.
If power is restored, e.g. the solar panel re-charges the battery, the XL2 can be reconfigured to automatically power back on and restart the measurement.
The XL2 hardware does need to be revision E or D2. You can tell your XL2 hardware revision from its serial number. A serial number of A2A-12345-E0 is revision E while a serial number of A2A-01234-D1 is hardware revision D1 and would need to be update. Use our RMA System to return the XL2 for update. Hardware updates are included free of charge as part of calibration.