I present my HBX 2997a TPU battery tray. You will need to relocate your ESC (usually what we all do first anyways). If you have moved it and want a more stable platform on top of your steering servo or have not moved it yet and want the best relocation/mounting solution, check out my ESC relocator plate HERE . This battery tray can be printed out of PLA but it will make the vertical sides more susceptible to breaking.

Ensure you clean the inside of the chassis location with ISO or something similar before using double sided tape to hold the tray down.

Tray dimensions are:

120mm long

32mm wide

30mm tall

I use a 1x20inch velcro strap. Easy find on Amazon. Amazon also sells create your own velcro strap kits.