Aerator - Battery Build


To power the Aerator, a 20400maH 12.6V pack needs to be built.  This is done using individual 18650 cells.  The battery cells will be installed into a custom 3D printed frame to fit the battery into the chassis of the Aerator


3S Protected Circuit

To create the battery pack we ned to buy individual 18650 LiIon cells.  Please use good quality Panasonic 18650B LiIon Cells.  Its worth investing in good quality batteries once.

These single cells can be purchased online (e.g. Ebay).  Don't be fooled by manufacturers claiming enormous cell capacities.  3400mah is the standard cell capacity.  I always use Panasonic NCR18650B cells.


Battery Construction


The battery case first needs to be printed using the provided STL files.  The upper lower and battery base should be printed in standard PLA material.




The 18650 Cells are arranged in the case as shown above.  Please take care to have the correct orientation of the battery (+/-) in the case.

Once the cells are correctly positioned in the lower case, the top case can be lightly tapped using a rubber mallet onto the cells to secure the pack.


The cells can be connected to each other as shown in the picture below  This is easily done by using Nickel Plated strips to connect the cells (or by using individual wires).  Spaces are provided in the custom battery case for the strips to fit between. The cells are connected together in multiple positions to ensure even charging and discharging of the battery cells.

If you are soldering the cells, please remember that you will need a lot of heat on the negative side of the battery to create a good solder joint.  (This is as the negative side includes the whole case which acts as a heat sink).






The BMS (Battery Management System) is fitted to the small recess at the front of the pack.  The B+ and B2 connections are easily made by curling a strip of wire in the provided recesses from the cells to the BMS.  

Due to the custom shape, the B1 and B- connections to the BMS need to made with some wire.  The connection points are shown in Yellow and Blue.


Yellow --> B1      &        Blue --> B-



An EC5 Connector should be used on the main terminals of the battery (P+ and P-)





Testing the Battery

Before charging the battery please make sure all the connections are working



Using a multi-meter you should measure the following DC voltages

  • Between B- and B1      3.2V - 4.2V
  • Between B- and B2     6.4V - 8.4V 
  • Between B- and B+     9.6V - 12.6V

If all this is correct you should measure:

  • Between P- and P+     9.6V - 12.6V

(If the first 3 voltages are correct and the last voltage is not correct it could mean a faulty BMS board)


If everything measure correct the battery is ready to be charged and installed.