Alkaline cylinder
A23 battery equivalent
BuyA23Alkaline · 12 V · 10.3 × 28.5 mm
Safe swap, same cell: MN21 · GP23A · 23A · KE23A · 4223
12 V · 10.3 × 28.5 mm · 12 V alkaline stack
A23 is a 12 V alkaline miniature cylinder. Energizer's sheet prints ANSI-1181A, 55 mAh to 6.0 V on 20 kΩ at 21°C, and drawing figures 10.30 / 9.70 mm and 28.50 / 27.50 mm. The replacement guide says it covers labels MN21/23, KE23A and 4223. Energizer's finder returns this product for GP23A. A27 is the thinner 12 V cell and does not fit an A23 clip.
| Chemistry | 12 V alkaline stack |
|---|---|
| Nominal voltage | 12 V |
| Diameter × height | 10.3 × 28.5 mm Energizer A23 drawing prints 10.30/9.70 mm and 28.50/27.50 mm. The figures used for size search are the maximums. |
| Designation on the datasheet | ANSI-1181A |
| Weight | Energizer 8.0 grams (0.3 oz.) |
Can I substitute it?
Not interchangeable with A27. Not a substitute for any coin cell. Twelve volts into a 3 V fob will destroy the device. GP23A is the finder label that returns this cell. The printed guide says MN21/23, not '23A'.
Size check at real size
Lay the old cell on the outline. This shows the top outline (diameter) and the side outline (height) at 1:1 once the screen is calibrated.
A23 outline, 10.3 × 28.5 mm. Not a photograph, drawn from the figures above.
Calibrate this screen
Screens scale pages differently, so true size is only true after calibration. Hold a bank card or ID card (85.60 mm wide, ISO/IEC 7810 ID-1) against the bar and slide until the bar is exactly as wide as the card.
Saved in this browser only.
All cells on one true-size sheet
When printing, set scale to 100% or Actual size, not Fit to page.
Capacity
| Source | mAh | Test as printed |
|---|---|---|
| Energizer | 55 | 55 mAh to 6.0 Volts |
Cross-reference
Each code is printed on the cited chart. A shared outline is not, by itself, the same cell.
| Where it is printed | Code |
|---|---|
| Listed label | MN21 |
| Listed label | GP23A |
| Listed label | 23A |
| Listed label | KE23A |
| Listed label | 4223 |
Devices named on the Energizer guide
Garage door openers, car alarms, lighters, key fobs, electronics. See car key fobs, garage openers, remotes and doorbells.
12 V mini cylinders, the N cell, and 9 V
A23 and A27 are stacks of alkaline manganese cells in a small round can, nominal 12 V, meant for key fobs, garage-door remotes and similar short pulses. Energizer's A23 sheet (ANSI-1181A) rates 55 mAh down to 6.0 V on 20 kΩ at 21°C. The drawing prints 10.30 mm and 9.70 mm on one axis and 28.50 mm and 27.50 mm on the other. The A27 sheet has no ANSI or IEC designation line (it prints 'N/A'), rates 22 mAh to 6.0 V on the same style of load, and prints 8.00 / 7.40 mm and 28.20 / 27.00 mm. They do not interchange. A 27 will rattle in a 23 holder, and a 23 will not enter a 27 holder. Neither belongs anywhere a coin cell belongs.
Energizer's replacement guide lists A23 as the cell that replaces MN21/23, KE23A and 4223. The specialty finder maps the label GP23A to the A23 product. The exact string '23A' is not printed on that guide. Searches for 23A are sent to A23 because that is the cell the finder returns for GP23A, and the gap is noted on the page.
The N cell is Energizer E90: ANSI-910A, IEC-LR1, 1.5 V. The sheet draws a maximum of 12.00 mm by 30.20 mm and does not state a single milliamp-hour rating, so none is shown. The 9 V transistor battery is Energizer 522: ANSI 1604A, IEC-6LF22 or 6LR61, 9.0 V, a rectangular can. Its sheet likewise gives capacity as a family of curves rather than one number.
Sources
Last verified 2026-10-29.
- Energizer battery cross reference guide Energizer, checked 2026-10-29
- Energizer A23 product datasheet (a23.pdf) Energizer, checked 2026-10-29
- Energizer specialty battery finder, label GP23A resolved to the A23 product Energizer, checked 2026-10-29