2S lithium battery series charger

Because I have a lot of 2s XT30 interface batteries, and the charger I have is b6, and I have to get an xt60 to xt30 adapter cable to charge them, and charging them one by one is too troublesome.
I wanted to be lazy, so I connected three 2s batteries in series to charge the 6s. It was very cool to charge 3 batteries at a time. Personal test is very easy to use.
 
Note:
1. In fact, the 2s lithium battery only needs to be connected to the balancing head for charging. The interface of xt30 can be left alone, so the board does not need to be soldered
. 2. The interface for BB ringing is reserved, so you can check the status of each battery cell at any time. Power (however, I measured it and found that the measurement of 5 or 6 cells would be inaccurate, but in the end it was all 4.2v after charging)
3. Due to the charging characteristics, try to have the voltage of each battery as close as possible before charging, otherwise there will be overcharge. possible.
4. The XT60 and the balanced head can be soldered directly. I used a socket for modularity.
5. In order to make it more beautiful, I drew a base casually, see the attached stl file. Install using M3 bolts and nuts.
 
picture: