Seatpost battery - Compatible with VELLO bike

I made a seatpost battery suitable for lights on my VELLO bike.

This sealing cap gets placed at the end of the seatpost. It gets fixed by a 4mm grub screw (see pictures), the model does not include the position of the thread. I put it on the side where the Wago connector ist placed. The grub screw must be secured in order to protect against shorts.
The used battery cells are 18650 type. I put 6 batterys inside my seatpost. They all got a battery cell holders at the ends with the clips removed and the corners rounded off to make shure that they fit in. They all got soldered to another (make shure what you are doing). My configuration is 2s3p. On two sides I glued on spokes in order to pull the battery out if needed.
The battery then get hooked up to the Usb C charger module and the Wago 733-202. Then they get placed inside the sealing cap and fixed by hotglue.
When putting all inside the seatpost, make shure that if the battery should slide onto the holder, it cannot damage any wires. Now the hole for the thread can be drilled at the rigth place. Mine is 8mm apart from the end and on the side where the Wago connector is situated.

Needed materials:

• Battery cell holder (https://www.aliexpress.us/item/3256806033560866.html)
• Usb C charger module (https://www.aliexpress.us/item/3256806880577946.html)
• Wago 733-202 (https://www.wago.com/de/steckverbinder/1-leiter-stiftleiste/p/733-202#details)
• Wago 733-102/037-004 (https://www.wago.com/de/steckverbinder/1-leiter-federleiste/p/733-102_037-004#details)
• 18650 batteries
• 2 Spokes
• 4mm grub screw
• Hot glue
• tape