Smart locks
August Wi-Fi Smart Lock (4th Gen) battery
2 × 3V lithium cell
August Wi-Fi Smart Lock (4th Gen) takes 2× CR123 / CR123A lithium. Replace both at once. Do not use rechargeable cells. Older August Pro / 2nd / 3rd Gen locks use 4× AA — confirm generation in the August app.
How to replace it
| How to open | Press the August logo at the bottom of the faceplate, tilt/remove cover, replace both CR123A cells positive (+) up, reseat faceplate. |
|---|---|
| Orientation | Match polarity markings |
| Low battery indicator | App or device low-battery cues where equipped |
| Notes | August Support: Wi-Fi Smart Lock uses 2× 3V CR123 / CR123A lithium. Replace both at once. |
| Access | Tool-free |
Important
- August Support: Wi-Fi Smart Lock uses 2× 3V CR123 / CR123A lithium. Replace both at once.
- Do not use rechargeable batteries (limited capacity) per August.
- Not the same as August Smart Lock Pro / 2nd / 3rd Gen (those use 4× AA).
- Battery identification only — no lock-bypass guidance.
Sources
Helpful for this device
Optional tools for opening, testing or charging — separate from the battery answer.
- Fluke 101 Digital Multimeter
Accurate open-circuit voltage and basic electrical checks
- Klein Tools MM400 Multimeter
General DC voltage checks including battery terminals
- Digital multimeter
Measure open-circuit voltage and general electronics checks
New battery but still not working?
A fresh 2 × CR123A should restore August Wi-Fi Smart Lock (4th Gen) 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 2 × CR123A (lithium). Rechargeable cells are not supported for this device. Same size does not always mean the same battery.
- Check known model-specific issues
August Support: Wi-Fi Smart Lock uses 2× 3V CR123 / CR123A lithium. Replace both at once. Do not use rechargeable batteries (limited capacity) per August. Not the same as August Smart Lock Pro / 2nd / 3rd Gen (those use 4× AA).
- Confirm the battery itself
For most coin cells, fitting a known-good fresh cell of the correct code is simpler than capacity testing.
- 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?
August Wi-Fi Smart Lock (4th Gen) is still sold new. Only buy another if a fresh battery and the checks above did not help.