---
layout: simple
title: Batteries
revisions:
- author: Cuu 
  date: 2024-02-22
  comment: First version
---
The 18650 batteries are NOT included in the package due to global supply
chain interruptions, as of writing. Finding 18650s in stock may require
extra searching.

There is an [extensive thread discussing
18650](https://forum.clockworkpi.com/t/battery-model-recommendation/6611/2)
batteries on the Clockwork Forums.

### Sizes

The 18650 comes in various sizes, and the DevTerm battery holder is
compatible with those sized **Φ18±0.5mm diameter, 65-69mm length**. If
oversized batteries are too big, they will put extra tension on the
battery springs or plastic cover, potentially denting the batteries or
damaging your hardware. This being said, many of the recommended
batteries are a "tight fit."

### Circuit Protection

The battery module has "Short Circuit and Reverse Polarity Protection"
features, but you are still advised to purchase the batteries from a
reliable distributor and install them correctly. Nitecore and Panasonic
are regularly cited as reliable bands that produce multiple 18650
models, some featuring protected cells to prevent accidental damage to
the batteries or DevTerm.

### Avoiding Counterfeits

18650 batteries are commonly used in [vaping
devices](https://en.wikipedia.org/wiki/Electronic_cigarette) and may be
available at local retail stores that carry such equipment. Beware of
counterfeit and/or poorly made batteries when ordering online. It is
best to stick with reputable brands.