---
title: "FR6 equivalent: FR14505, L91, 15-LF"
description: "The FR6 is a 1.5 V lithium (primary) cell, also sold as FR14505, L91, 15-LF. Full equivalents, what does not substitute, and where it is used."
url: https://atoneplace.net/battery/fr6/
site: "At One Place"
---

# FR6 battery

**What replaces a FR6: FR14505, L91, 15-LF, Energizer Ultimate Lithium AA, FR6/L91**

1.5 V lithium (primary), 14.5 × 50.5 mm (diameter × height)

The FR6 is a single-use 1.5 V lithium (primary) cylindrical. The codes below are the same physical cell sold under different manufacturer names, and any of them will fit.

## Specification

- **IEC designation:** FR6
- **ANSI / NEDA:** 15-LF
- **Nominal voltage:** 1.5 V
- **Chemistry:** Lithium (primary)
- **Size:** 14.5 × 50.5 mm (diameter × height)
- **Typical capacity:** 3000 mAh
- **Rechargeable:** No — never charge it

## Codes that mean the same battery

*Different manufacturers, one physical battery. Voltage, chemistry and dimensions all match.*

| Code | Fits? |
| --- | --- |
| FR14505 | Yes — same cell |
| L91 | Yes — same cell |
| 15-LF | Yes — same cell |
| Energizer Ultimate Lithium AA | Yes — same cell |
| FR6/L91 | Yes — same cell |

## Codes that look close but are not

| Code | Why it is not a substitute |
| --- | --- |
| 14500 | Also an AA-shaped lithium cell, but rechargeable lithium-ion at 3.7 V. The FR6 is a 1.5 V primary and a legitimate AA replacement; the 14500 is not. |
| LR6 alkaline | The FR6 replaces an alkaline AA in almost everything, but it holds a higher voltage under load, weighs a third less, and works to −40 °C. A handful of devices — some medical equipment and older cameras — are specified against it, and a very few chargers will attempt to charge it, which it must never be. |

> The FR6 is a primary cell and must never be put in a charger. Charging a sealed primary battery builds gas pressure inside a can with no vent designed for it, which is how they rupture or catch fire. Rechargeable look-alikes exist for several sizes and carry different codes — check the code, not the shape.

## Where it turns up

- Digital cameras and speedlights
- Trail cameras left out over winter
- GPS units and avalanche transceivers
- Smoke alarms wanting a ten-year cell

> Lithium/iron disulfide — the F prefix in IEC 60086. It is the only lithium chemistry that gives 1.5 V, which is what makes it a safe alkaline substitute where 3 V lithiums are not.

## Common questions

### What is equivalent to a FR6?

FR14505, L91, 15-LF, Energizer Ultimate Lithium AA, FR6/L91 — all the same 1.5 V cell under different manufacturer codes.

### Can I use a 14500 instead of a FR6?

Also an AA-shaped lithium cell, but rechargeable lithium-ion at 3.7 V. The FR6 is a 1.5 V primary and a legitimate AA replacement; the 14500 is not.

### Is the FR6 rechargeable?

No. It is a primary cell — charging one risks rupture or fire. Rechargeable look-alikes exist in the same size under different codes.

## Related pages

- [LR6 battery](https://atoneplace.net/battery/aa/)
- [LR03 battery](https://atoneplace.net/battery/aaa/)
- [ICR18650 battery](https://atoneplace.net/battery/18650/)
- [LR20 battery](https://atoneplace.net/battery/d/)
- [HR6 battery](https://atoneplace.net/battery/nimh-aa/)
- [LR14 battery](https://atoneplace.net/battery/c/)
- [CR17345 battery](https://atoneplace.net/battery/cr123a/)
- [HR03 battery](https://atoneplace.net/battery/nimh-aaa/)
- [8LR932 battery](https://atoneplace.net/battery/a23/)
- [INR21700 battery](https://atoneplace.net/battery/21700/)
- [4LR44 battery](https://atoneplace.net/battery/4lr44/)
- [CR15H270 battery](https://atoneplace.net/battery/cr2/)

## Sources

- Official vendor product documentation — At One Place (/about/)