In April and May of 2014, some LabQuest 2s missed the on-board fuel gauge programming step (details below). This can be fixed by updating to 2.3.1 or newer at:
How can I tell if my unit has not been programmed?
Go to System:System Information:Battery
The parameter FullAvailableCapacity should be a number over 3000. If it is under 1000, the unit has not been programmed.
What units are affected?
LabQuest 2 units with serial numbers 14004311 through 14014489. (This is stamped on each unit near the bar code on the back label.)
As part of the manufacturing process, the on-board fuel gage is programmed with a profile to match a typical LabQuest 2 battery. A temporary process change caused this step to get skipped. The result is the fuel gage does not work correctly on these units, causing problems such as "not holding a charge", "won't charge" or "bad battery". We have since corrected our manufacturing process to ensure that the problem does not happen again.
TIL 2741: LabQuest 2 Battery Troubleshooting and FAQs