Dittos to what Phayd said. I have in some extreme cases mounted the battery externally in front of the firewall or under the engine mount beams, just slip it into a baggy.

I don,t know if the LT-40 has a tank hatch or not but if it does just remove the tank, wrap the battery in a little foam and slid it into a baggy and tape the baggy opening to the rear around the wire. Lay it in the bottom up aginst the firewall or thereabouts.
cut a piece of 1/4 square balsa stick the width of the compartment push it down over the battery and CA the ends to the fuse sides, put another at the rear to keep the battery from sliding to the rear, reinstall the battery and your done. If you don,t have a tank hatch I highly recomend you make one all sport airplanes really should have one and particularly trainers. About the only airplanes I do not use a hatch is my pylon racers and thats only because of the need to keep a very strong nose box to carry power loads.

John

Oh almost forgot, Never put a Rx in that area.