g&g gr16 rail's

[gotchya24]

so ive been looking at a gr16 by g&g, and i want to change it up a bit by getting tactical rails so i count mount flashlights etcetc.

im thinkin about either one of these rails from ehobby:

http://shop.ehobbyasia.com/accessori...handguard.html

http://shop.ehobbyasia.com/accessori...handguard.html

but heres the problem...i figure that the normal stock 9.6v battery wont fit in there cause itll probably be too tight with a big battery like that..
im wondering if theres any batteries out there that would fit into the rail system..i found a battery on ehobby, but im not sure if this would fit

http://shop.ehobbyasia.com/bb-batter...twin-type.html

i dont wanna put the battery in a box on the side of the rail..and i wanna keep the stock that it originally comes with...the onli alternative i have is to change the stock to something that would fit the battery..but id rather not change the stock if i dont have to..

so if theres any batteries out there that you know/think would fit into inside the rail, your recommendations would be greatly appreciated!! thanks in advance

[Hash Vapor]

You might want to look in Lithium Polymer batteries. They are small and powerful, just be sure your gearbox can handle them.