---
title: "INR21700 equivalent: 2170, INR21700, NCR21700"
description: "The INR21700 is a 3.6 V lithium-ion (rechargeable) cell, also sold as 2170, INR21700, NCR21700. Full equivalents, what does not substitute, and where it is used."
url: https://atoneplace.net/battery/21700/
site: "At One Place"
---

# INR21700 battery

**What replaces a INR21700: 2170, INR21700, NCR21700, 21700 Li-ion**

3.6 V lithium-ion (rechargeable), 21 × 70 mm (diameter × height)

The INR21700 is a rechargeable 3.6 V lithium-ion (rechargeable) cylindrical. The codes below are the same physical cell sold under different manufacturer names, and any of them will fit.

## Specification

- **IEC designation:** INR21700
- **Nominal voltage:** 3.6 V
- **Chemistry:** Lithium-ion (rechargeable)
- **Size:** 21 × 70 mm (diameter × height)
- **Typical capacity:** 4800 mAh
- **Rechargeable:** Yes

## Codes that mean the same battery

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

| Code | Fits? |
| --- | --- |
| 2170 | Yes — same cell |
| INR21700 | Yes — same cell |
| NCR21700 | Yes — same cell |
| 21700 Li-ion | Yes — same cell |

## Codes that look close but are not

| Code | Why it is not a substitute |
| --- | --- |
| 18650 | Three millimetres wider and five longer, holding around half again the charge. A 21700 will not enter an 18650 tube; an 18650 in a 21700 tube rattles and may arc. |

## Where it turns up

- Tesla Model 3 and Model Y packs
- Modern high-output torches
- E-bike and scooter batteries
- Newer cordless tool packs

> Genuine capacity runs 4000–5000 mAh. The name is the size: 21 mm across, 70.0 mm long.

## Common questions

### What is equivalent to a INR21700?

2170, INR21700, NCR21700, 21700 Li-ion — all the same 3.6 V cell under different manufacturer codes.

### Can I use a 18650 instead of a INR21700?

Three millimetres wider and five longer, holding around half again the charge. A 21700 will not enter an 18650 tube; an 18650 in a 21700 tube rattles and may arc.

### Is the INR21700 rechargeable?

Yes. Use a charger made for its chemistry and never substitute a primary cell of the same size.

## 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/)
- [FR6 battery](https://atoneplace.net/battery/fr6/)
- [4LR44 battery](https://atoneplace.net/battery/4lr44/)
- [CR15H270 battery](https://atoneplace.net/battery/cr2/)

## Sources

- Typical range compiled from manufacturer specifications — At One Place (/about/)