does Magpul PTS make a battery stock or could one of these be modified to fit one?
http://shop.ehobbyasia.com/magpul-pts-acs-carbine-stock-for-m4-m16-series-multicam.html
http://shop.ehobbyasia.com/magpul-pts-ctr-stock-for-marui-m4-m16-multicam.html
http://shop.ehobbyasia.com/magpul-pts-acs-carbine-stock-for-m4-m16-series-multicam.html
http://shop.ehobbyasia.com/magpul-pts-ctr-stock-for-marui-m4-m16-multicam.html