I am not sure what every use means: duration, programs running etc. But that drainage is properly excessive. TI estimates that with 2 hours a day of usage, the batteries should last a school semester.Possible causes of rapid drainage.
The most common causes of rapid battery drain are mismatched batteries
- Batteries of different brands
- Batteries of different types (alkaline (1.5V + rechargeable NiMH 1.2V)
- Batteries of different charge levels (new batteries with old ones)
- Negative charge build up
Another cause of rapid battery drain is the use of third-party programs: Certain of them keep large amounts of data in memory. Some of them are tweaked to bypass the TI power management scheme and disable the TI APD
(automatic Power Down ) after 5 minutes of inactivity.Possible remedies
If that fails
- Remove all batteries (main batteries and backup battery)
- Leave them out of calculator for about 15 minutes. (Beware that this will clear the contents of the memory and that data will be lost along with all applications installed). However Applications cam always be reinstalled once calculator returns to its normal state.
- The possible benefit of the removal of all batteries is to make the negative charge build up disappear.
If the foregoing steps fail to restore the calculator to its normal behavior, you may have to contact TI Customer Assistance by filling out and submitting a customer assistance form.