Nissan Leaf EV Battery

WARNING :  

Batteries of all types are dangerous. Do not attempt any

work you are not qualified to perform.

 

I saw a long list of EV battery modules on Ebay in the midst of my EV car research, and thought whoa ! I could evaluate its internals and use it for my drones and other robotic projects. I think with a 3C output that means 100 Amps which does seem plausible when attempting to lift a drone. I just dont know how to cool it off.

The battery as purchased and unmodified. The two large outer terminals are for power output and the white small one in the middle is the balance tap.

The module in OEM form was purchased used for 75 US $. The previous owner was a builder like myself and used it briefly for an electric skateboard.

Some OEM module specs :

Case : Formed thin aluminum sheet metal.
Type : Pouch, 4 cells. 32.5 Ah and 3.75 V per cell.

Circuit : 2 series 2 parallel at 7.6 volts nominal, 60 to 90 amp normal output.

Mass : 3.787 kg (8.4 pounds)
Dimensions : 22.2cm W x 30.7cm L x 3.7cm H   (8.75 in. W  x  12.1 in. L  x  1.47 in. )

Chemistry :
Cathode = LiMn2O4 with LiNiO2

Anode = Graphite

The battery after aluminum removed, terminals visible.
Much of the Aluminum and plastic removed.

Specs after liberation :

Mass : 3.293 kg (7.3 pounds)
Dimensions (Cell Stack) : 21.6cm W x 29.2cm L x 3.3cm H  (8.5 in. W  x  11.5 in. L  x  1.3 in. )
Mass removed = 493 g (1.1 pounds) 14.6 % lighter.
Connecting bars : 0.252 cm^2 in cross section and several centimeters long. Seemed to be harder to cut than natural copper. (Appx 3 or 4 awg equivalent.)

The copper tabs. Very thick and wide for low voltage drop at high current. Now each cell can be wired independently in series or parallel a needed.
Removed material and battery.
Positive, balance and negative Connections.
Terminal after being cut off. It was clearly harder and stiffer than normal copper. A alloy definitely chosen for efficiency
Very sensitive film sealed cells.

Left: Here the battery is about as  disassembled as it can safely be. Its very vulnerable to being pierced.