Battery straps for FLM chassis???

What are you guys using at the moment? I am using the gorilla maxx straps with the flm ones. I have used zip ties to attach the gorilla maxx straps since i need some nuts to be able to use screws, and i always break a zip tie when i bash lol, i thought thats fine better the zip tie than the strap but now it has gotten annoying and the gorilla maxx strap is nearly ripping. So i thought oh well and used 2 zip ties per side and zip tied the batteries to the chassis aswell as used the gorilla maxx strap and it still didnt work, the battery still moved and hit the rear shocks. so what are u guys using that holds the batteries on really well? its kinda weird how the chassis is nearly flat which allows the batteries to come out the side, and move around, wouldnt it be better to have something like the stock chassis? like how the battery tray on the stock has walls so the battery cant fly out.