CNC-machined battery pack backstop for XRAY X12ââ¬â¢22 made from premium-grade graphite material. The battery pack backstop and rear link brace allow for a wider array of battery positioning adjustment and match battery pack size. Frontward-placed battery pack makes the car simpler to drive, decreases wheel lift in corners, and makes the vehicle more predictable over bumps. Rearward-placed battery makes the vehicle more aggressive, increases cornering speed, but makes the vehicle harder to operate a vehicle.