My brand new LabQuest 2 battery doesn't work.

This information pertains to LabQuest 2.
If you have an original LabQuest, see Original LabQuest Battery Troubleshooting and FAQs

The LabQuest 2 battery ships with a small translucent sticker over the contacts to protect it from accidental contact. Verify that this sticker has been removed and make sure there is no residue on the battery contacts. If there is residue, clean the contacts with a dry cloth. Insert the battery and then charge for 12 hours.

If the battery is not charging, see TIL 2741: LabQuest 2 Battery Troubleshooting and FAQs