How often do you need to charge a stun gun?

A common question we get is how often do you need to charge a stun gun. 

First off, it's important to know that not all stun guns are rechargeable. TASER brand stun guns are usually not rechargeable (at least the civilian versions) with the exception of the Strikelight 2. 

Stun guns that are rechargeable, do not follow a specific standard, so performance will vary greatly between models. In standby (without being used or without switching the safety off) a decent stun gun should stay charged several weeks at the very least. If however you switch the safety off, then many models have some sort of LED indicator that confirms that the stun gun is live and ready to discharge, or sometimes a battery indicator. The LEDs actually slowly drain the battery slowly, so the lifetime of the battery can be reduced to a week or even days in extreme cases. If battery life in live mode is important to you, look for models that don't use indicator LEDs, or models which turn off the LEDs after a brief period of time. 

The other important factor that plays into the battery life is the size of the battery. With the exception of stun guns that use removable batteries, battery capacity is rarely specified in the stun guns' datasheets. As a simple rule of thumb, the larger the battery, the more charge it can store, so avoid very small models if battery life is important to you.

To see some real life measurements, check out this article.