extra space in 2.4 transmitter what is it for?

[vwbug]

just like the title says in my 2.4 transmitter it has 2 spaces one for batteries and i use the other one for the sheet and i was wondering if the place the sheet goes can be a spot for a battery because of the connecter and does traxxas have a battery for that? I think i explained that well haha.

[Captain_Rusty]

I've heard something about battery packs going there but never heard of anyone actually using it. Most use it to store the sheet or body pins or small Allen keys for quick adjustments/repairs in the field

[Jimmie Neutron]

The extra space is there because that same body used to hold 8 batteries.
The port is for factory use only.