Here's Airsoft GI Bob describing the LiPoly batteries just recently released by Tenergy that should fit in spaces in some AEGs where previous types of batteries can't... "These new Tenergy Batteries are smaller than some other Lipos on the market, meaning that they will fit into guns that are traditionally tough to get batteries into. If you have a SIG 552, G36C/K/Rifle."

Check all the Tenergy Batteries at the Airsoft GI Online store.