Hummer H3 key fob battery
3 of the 5 model years listed for the Hummer H3 have a proven battery. The most common answer is CR2032. Rows below run oldest to newest; a year can appear twice when the car came with more than one kind of key.
- 2006Remote (separate)
CR2032
FCC ID L2C0007TOwner's manual: uhs-hardware.com and assets.gm.com (checked Nov 2, 2026)
Manual text: “replace the battery with a three-volt CR2032 or equivalent”
Find CR2032 on Amazon - 2007Remote (separate)
CR2032
FCC ID L2C0007TTwo sites agree: uhs-hardware.com and manualsdir.com (checked Nov 1, 2026)
Find CR2032 on Amazon - 2008Remote (separate)
Not confirmed yet
- 2009Remote (separate)
CR2032
FCC ID L2C0007TOwner's manual: uhs-hardware.com and assets.gm.com (checked Nov 2, 2026)
Manual text: “Insert the new battery. Replace with a CR2032 or equivalent battery.”
Find CR2032 on Amazon - 2010Remote (separate)
Not confirmed yet
Changing the battery
Separate remote fob
- The remote is a small standalone unit. You will not need to touch the ignition key at all.
- Turn it over: some older fobs use one small screw, newer ones just clip. Pry at the seam once any screw is out.
- Lift the old coin cell out and press the new one in with matching orientation.
- Close the fob and test it. If it does not work, open it again and check the cell is seated flat.
A CR2032 is 20 mm across and 3.2 mm thick. CR2032, CR2025 and CR2016 share the same width but not the same thickness, so a swap between them can leave a loose contact or a case that will not close.
If a child might have swallowed a coin cell, treat it as an emergency and get to a hospital right away.