Parkside X20V battery in Ferrex tool (with reverse side entry)

All parts were printed with PETG with a resolution of 0.28mm and with supports.

In addition to the printed parts, you will need 4 screws identical to those in the photo plus 3 BX2091C terminals 

https://www.aliexpress.com/item/1005004612347066.html?spm=a2g0o.order_list.order_list_main.5.21ef18029GUYot

and 3 Spade 6.3mm male terminals 

https://www.aliexpress.com/item/1005001726738591.html?spm=a2g0o.order_list.order_list_main.140.21ef18029GUYot

Three wires of about 70mm are also needed.
The positive and negative wires should be 16AWG. The third wire can be thinner as it serves to transmit the temperature sensor signal and does not need significant current.

The slots for inserting the terminals are very tight so they can stay in place until you apply the glue, so it takes a little effort and patience to insert the terminals.
I recommend hot glue to secure the terminals in place.

The terminals must be placed as shown in the photos.

If you want an adapter where the battery goes through the same side as the original tool, check out this model:

https://www.printables.com/model/329087-parkside-x20v-team-battery-in-ferrex-tool-battery-

Do not use the Ferrex charger to charge the Parkside battery.