Boston Swing 5300 Lithium ion Cell

As the special NCM system with rare earth material and special structural, Boston cells have high energy density(207Wh/Kg,490Wh/L),long cycle life,fast charging ability, and wide temperature performance(-40~70degrees).

Typical capacity: 5300mAh
Voltage: 3.65V
Charging end-voltage: 4.23V
Discharging end-voltage: 2.75V

This model cell mainly application on the power in the electric bus, its dimension same as 2 18650 parallel connection. Mostly people will treat it as 2 18650 cells,but more if you see our following test photos. 

Following is the dis-part Boston 5300 cell
Please be careful and full discharge cells before dis-parting it.
1) Each cell have its series number and QR code

2) Using diagonal pliers cutting around the edge of the cell

3) Cutting the round of the edge slowly

As you can see the circle on the cell, that’s the cell protection. (Maybe battery get wrong, it will be ballooning) ,but it welded on the inner connection tap(maybe it will power-off when ballooning ).
Now the following sampler circle is battery negative port(GND).

Both negative and positive port from 2 taps connection, and The inner resistance will be smaller.

The plastic plate under the case as protection.

4) Cut down the connection one by one.

5）Take away the white plastic protection case.

6) It’s hard to take the inner part out, then we cutting the battery outside case.

7) Now we see the inner part structure.

The dark green tapes rolling together. And there nothing on the bottom of cell.

8) Let’s do short-circuit. And the yellow tape on the battery connection is burning. Boston swing 5300 cell really still has strong power!

9) Left the connection of short-circuit, the fire stopped.

10)Now we dis-part it completely,it’s very clearly now. Four different layers in one rolling, Two layers port, Two layers film(electrolyte inside).

If you think its welding together, that’s wrong. It’s just 2 layers rolling together. And it more than 1.5m longer.

One is Copper, and another maybe Ali-um(not sure whether is AL). And both sides have aquadag coating.

If you want see more? Oh,no,please you can’t make them as cell again.