I think the dimensions are wrong for the "Elite Airsoft 3000 mah 9.6v Double Nunchuck battery pack" on the cheapbatterypacks website (
http://eliteairsoftbatteries.com/pro...tery-pack.aspx). I think it might fit in our m4 hand guards...
if that pack is using the 2/3 type cells then i don't see why it wouldn't fit as its just about the same as a small type battery pack except 2 of them. the elite 1500mah cell is supposed to be 2/3 type and .7in x 1.1in. I am pretty sure the height being stated as 1.3440in is a mistake, i have emailed them and if I am right, then this might be the very best 9.6v battery you can fit in the m4 handguard.