LiftMaster · Garage remotes
LiftMaster 878MAX keypad battery
1 × 9V alkaline
LiftMaster 878MAX keyless entry takes 1× 9V alkaline. Replace when the keypad dims. This is not the CR2032 handheld MAX remote answer.
How to replace it
| How to open | Insert a flat-head screwdriver into the oval cutout at the top of the battery cover, slide the cover down, replace with a new 9V alkaline, slide cover up until it locks. |
|---|---|
| Orientation | Match polarity markings |
| Low battery indicator | App or device low-battery cues where equipped |
| Notes | Chamberlain Group documents 878MAX with other wireless keypads as 9V alkaline. |
| Access | tool_assisted |
Important
- Chamberlain Group documents 878MAX with other wireless keypads as 9V alkaline.
- Amazon/retail listings also specify 1× 9V for 878MAX — not AA and not CR2032 remote cells.
- Identify by keypad model 878MAX — not the opener model alone.
Sources
Helpful for this device
Optional tools for opening, testing or charging — separate from the battery answer.
- Ansmann Energy Check LCD
Quick household cell check (good / low / replace)
- ZTS Mini-MBT Multi-Battery Tester
More informative state-of-charge style checks across common formats
- Battery tester
Quick good / low / dead check for household cells
New battery but still not working?
A fresh 1 × 9V should restore LiftMaster 878MAX if the battery was the problem. Work through the checks below before replacing the device.
- Check orientation
Confirm the cell is seated correctly: Match polarity markings
- Check the battery type
This device needs 1 × 9V (alkaline). Rechargeable cells are not supported for this device. Same size does not always mean the same battery.
- Check known model-specific issues
Chamberlain Group documents 878MAX with other wireless keypads as 9V alkaline. Amazon/retail listings also specify 1× 9V for 878MAX — not AA and not CR2032 remote cells. Identify by keypad model 878MAX — not the opener model alone.
- Confirm the battery itself
If you have a battery tester or multimeter, check the cell. A low open-circuit voltage often means replace; for rechargeable AA/AAA, a capacity test is more informative than voltage alone.
- Still not responding?
If a correct, fresh battery installed properly does not restore the device, the fault may be elsewhere — the device may need service or replacement.
Need to replace the device?
LiftMaster 878MAX is still sold new. Only buy another if a fresh battery and the checks above did not help.