Universal camcorder Li-Po battery pack with USB-C charging

I acquired a vintage camera with a dead Ni-MH battery at a flea market. I wanted to experiment with it and create some old-school VHS vaporwave videos :)
 

I designed a battery pack with the main idea that it can be charged from modern USB-C PD chargers in the field or run while charging.
 

A word of caution: When working on your own hardware projects, remember that Li-Po batteries should not be soldered in a charged state (discharge them first) or damaged in the process, as it poses a potential fire hazard. Also, please pay attention to the polarity and avoid mixing positive and negative wires.

The maximum capacity depends on the cells you put inside.

It operates with 2x 3.7V Li-Po batteries in a 2S (two in series) configuration, with a maximum charged voltage of around 8.4V. However, this voltage drops under load, which is close to the 6V of the Ni-MH (7.5V). My camcorder handled it without any problems. Additionally, you'll need a BMS (Battery Management System) and a USB PD charger board because you need to balance the charge on the cells while charging due to differences in internal resistance and capacity of the batteries. Likely there is all-in-one module available to buy.

What will you need?
 

2x Li-Po cells that fit the case (I used ones from a portable DVD player)

1x Charging PCB like this one: https://www.aliexpress.com/item/1005004846748321.html?spm=a2g0o.order_list.order_list_main.103.58c01802SIPhr1

1x Printed top cover

1x Printed bottom parts

Nickel tape to create contacts

Some glue to assemble it

You can find the schematics on the charger link above.
 

You can secure the nickel contacts with superglue or a soda solution, creating a sturdy polymer that will hold the contacts in place and prevent them from bending.

Some printing hints:

Can be printed from whatever you want - PLA is common. Use supports. 

Feel free to reach out if you have any questions :)