Originally Posted by protc3

tape is the best way to secure the batteries but it is a pain.it is difficult to use a solid strap because battery packs dont usually stay perfectly straight when you solder them together so they will have a slight mismatch to the battery slots.if you solid clamp them it will tweak the chassis with the batteries slightly mismatched to the slots.some remedies for this are flexible optional hold downs such as O rings or rubber bands.this method will need some sort of locator plate for the battery to keep it from moving but can still move when taking a good hit.for big events i ALWAYS use tape.for club racing when i am short of time i use an O ring to hold my batteries and it does the job.for the stock L4 chassis,just put the tape through the slots and get it in place,install the batteries and then tape them over.this is going to be the easiest tweak free method without making your battery packs perfect.hope this helps