We have a Drive Scout mobility scooter that was missing the charging port cover. The screw, spring and plastic pin were inside the case, fortunately it did not cause a short circuit. There are 8 screws attaching the top of the battery case. 2 are under pressed in guide pins ( see the picture). The screw and spring worked well with the cover I designed.
I printed the cover using:
PLA+
100% infill (it's a small part)
This cover is probably the same on other charging ports.
The author hasn't provided the model origin yet.