My boys have several of the Mototec 48v electric dirt bikes, the batteries that come from the factory are prone to corrosion failure over time, rather than continue to fight the nightmare that is heavy wall shrink material for sealing up the batteries after a repair, I landed on this simple enclosure. I have installed them preventatively in the hopes that the better enclosure keeps the newer batteries from having corrosion issues and makes servicing the battery much less of a headache in the future.

The lid is designed to accept the following cord grip from amazon: https://a.co/d/98QSORe . But any 1/2" NPT cord grip would also work just fine.

I used RTV to seal up the surface between the lid and box, I simply tapped the holes to 3mm threads directly into the plastic, the corner holes are very close to the outer wall, and I had to tap in stages so I didn't cause the outer wall to fail. Not an issue long term because the RTV is what I am relying on to keep the battery sealed, the screws are simple a clamping mechanism to ensure I get good contact with the RTV.

I printed with standard supports @ .20 layer height with a .4 nozzle on a Creality K2 Plus, the supports are only needed for the lip of the lid and the cord grip inset. I used Polymaker Pro PLA.

I then used some neoprene foam weather stripping with an adhesive back to give the battery something to rest against on all sides. This makes the battery just slide in with a small amount of resistance, but pulls out without damaging anything. If I service one of the batteries again, I will try to remember and take some pictures of the inside of the box and the foam weather stripping. One thing you will want to be careful of is that the bottom of the battery is supported evenly since the bottom is where the junction between the 6s and the 7s portions of the battery lives and if you don't support them evenly, the nickel plated bus bars can fatigue and begin cracking. I have found this to be the case even with the factory batteries, so I have taken care to make sure that there isn't any undue stress on that joint.

Mototec 48v Dirt Bike - Lithium Battery Pack Enclosure

0.2mm layer, 2 walls, 15% infill