What batteries does a GSM device run on?

The battery type most often used today in consumer electronics, such as a mobile phone for example, is of the lithium-ion (Li-Ion) type. The main reason for this is that it has the greatest power density (ie the battery can be lighter than a NiCd or NiMH battery of the same power), and it has no “memory effect”. The latter means that you do not have to completely discharge the battery before recharging it.

For more information about Li-Ion batteries, please refer to:

http://electronica.infonu.nl/diversen/2166-litihium-ion-Battery.html

For a comparison between the different types of rechargeable batteries I have also added a number of links. Hopefully this answer sheds some light in the darkness.

Kind regards,

Jurgen.