- Control backlight: it should be is in auto-mode (if you use the full backlight for all time the battery lasts less).
- control the volume of the audio variometer (the maximum volume makes the battery last less, specially if you have a sink tone continuous and persistent);
- before all charge the instrument for 12-13 hrs to give a full charge and verify if the battery has a good duration.
- Verify that the charger works correctly (try to charge the instrument using a different charger - at least 4 Amperes required for the Compass instruments).
- Verify that the power line is 220 V (in some Countries it is less and it takes much more time for a complete charge).
- follow the instructions described for the next problem (battery level wrong).
Remember that the performance of any battery decreases due the aging. After a year of use it is normal that the battery starts to last a bit less. If you use your instrument a lot, we recommend to change the battery after 1 1/2 years of use. Anyway, many instruments don’t need the battery replacement even after 4 years of use.