HP · Calculators
HP 12C battery
2 × 3V lithium coin cell
How to replace it
| Compartment | Rear cover |
|---|---|
| How to open | Slide back cover off |
| Orientation | Positive (+) facing outward |
| Notes | Replace one battery at a time; do not use rechargeable cells |
| Access | Tool-free |
Important
- Modern HP 12c Quick Start specifies two CR2032 — older vintage 12C generations may differ; keep separate if documenting classic models
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 × CR2032 should restore HP 12C if the battery was the problem. Work through the checks below before replacing the device.
- Check orientation
Confirm the cell is seated correctly: Positive (+) facing outward
- Check the battery type
This device needs 2 × CR2032 (lithium). Rechargeable cells are not supported for this device. Same size does not always mean the same battery.
- Check known model-specific issues
Modern HP 12c Quick Start specifies two CR2032 — older vintage 12C generations may differ; keep separate if documenting classic models
- 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.