Mavic Mini : B0B DIY battery parts

thingiverse

Here are some parts to build DIY batteries for Mavic Mini: http://aeropic.free.fr/B0B/ The most challenging part of building a DIY battery is creating the battery connector. If you don't get the genuine DJI one, I found a way to make a female battery connector. The genuine lyre of DJI's battery connector offers 4 contacts to the male pin. The DIY battery connector will also offer 4 contacts per pin. To create this connector, I simply extracted some female lyres from a 2mm pitch square pins connector and placed them two by two inside a 3D printed case. Soldering in place can be difficult, so it's best to use a male connector or at least a male pin to keep the pair of females in place while soldering. Be patient, the result is excellent - we get the same four contacts to the male pin as with the genuine one. Insertion into the male connector requires less force than with the genuine one. If the MM draws 10 A, this gives 5 A per pin, since Vdd and GND are duplicated, which turns into 2.5 A per lyre and 1.25 A per contact... It does a perfect job on B0B! To make battery soldering easier, use the 3D printed template. Print it and glue 2 pins inside the holes. Mark the polarities on the template to avoid any mistakes. Insert the female 8 pins connector, and place the cells in contact with the connector. Hot glue the 2 cells together and attach the connector to the cells with some strong double-sided tape. You can now solder your cells to the connector - only 3 pins from both sides need to be connected. Remove the two middle pins. Don't forget to solder the other side in series and add a one-pin dupond connector to charge and balance the cells. You can 3D print the B0B_center_batt thing in spiral vase form. Glue it under the cells, and it will help centering correctly the battery inside the Mavic Mini hole. The conic slot is to be set at the opposite of the connector. Finally, you need a way to secure your battery to the mavic mini - see MM_B0B_lock.stl.