> For the complete documentation index, see [llms.txt](https://docs.sevenpens.com/drawtab/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.sevenpens.com/drawtab/core/power/powering-pen.md).

# Powering a pen

## Overview

To work, a drawing tablet pen requires a little power. Either a pen gets power from the tablet wirelessly (Passive EMR), or the pen uses a battery (Active EMR). For many years now, tablets have used Passive EMR pens almost exclusively.

## Passive EMR pens

Passive EMR refers to EMR technology where tablets wirelessly power the pen. All modern drawing tablets use Passive EMR. Their pens get power just by being close to the tablet, at about 10mm. The pens do not have a battery that needs to be recharged or replaced.

Wacom has been using Passive EMR for many decades. For non-Wacom tablet brands, the transition to Passive EMR happened within the last 10 years.

## Active EMR pens

In contrast, Active EMR is when the pen is powered by an internal battery. The battery is either replaceable or rechargeable. If it is rechargeable, then the tablet will come with a special cable that plugs into the pen and then usually to a USB port on your computer for charging.

## Cross-compatibility

* Passive EMR tablets can only be used with Passive EMR pens
* Active EMR tablets can only be used with Active EMR pens

## Notes on replacing or upgrading

If you have an older Active EMR pen, you cannot replace it with a Passive EMR pen.