9V battery reference
A 9V battery is a rectangular 9-volt cell with snap-style terminals on one end, commonly called a pp3 or 6F22.
Exact specs
| Designation | 9V (IEC: 6LR61 alkaline, 6F22 carbon-zinc) |
|---|---|
| Width | 26.5 mm |
| Depth | 17.5 mm |
| Height | 48.5 mm |
| Nominal voltage | 9V |
| Typical capacity | 400–600 mAh (alkaline) |
| Terminal type | Snap connector (pos: small cap, neg: large ring) |
What devices commonly use it
Smoke detectors, guitar effects pedals, AM/FM radios, and some multimeters use 9V cells.
What it's interchangeable with
NiMH rechargeable 9V cells (8.4V nominal) work in most applications. Lithium 9V cells deliver more stable voltage and longer life in smoke detectors.
What it's NOT interchangeable with
The polarized snap connector physically prevents reverse insertion, but ensure terminal polarity matches the device's connector orientation.
Common mistakes
- Snapping the battery in with reversed polarity awareness — snap connectors are keyed but always verify.
- Assuming 9V cells last as long as AA in comparable jobs — capacity is much lower.
- Leaving 9V cells in smoke detectors for more than a year without replacement.