Battery loading and unloading mechanism

A battery comprising:

• a back frame portion having a back surface and a thickness extending towards an insertion surface of the battery, the back surface also having a width;
• a first projecting portion being within the width of the back surface and being within the thickness of the back frame portion;
• and
• a second projecting portion being within the width of the back surface and being within the thickness of the back frame portion,
• wherein the first projecting portion extends from a first longitudinal end of the back frame portion and has a first shape, and
• wherein the second projecting portion extends from a second longitudinal end of the back frame portion and has a second shape different from the first shape.

An electronic device having a battery insertion portion configured to receive a battery,

• wherein the battery comprises a back frame portion having a thickness extending towards an insertion surface of the battery and a first side surface connected to and substantially perpendicular to the back frame portion,
• the back frame portion further comprising a first projecting portion and a second projecting portion having different shapes from one another located at both longitudinal ends of the back frame portion and being within the thickness of the back frame portion,
• the first and second projecting portions being located in a plane substantially perpendicular to the first side surface,
• the back frame portion being opposite to the insertion surface of the battery inserted into the electronic device, whereby the battery formed in the flat almost rectangular parallelepipedic shape and having an almost-square main surface is prevented from being erroneously inserted into the electronic device.