67.2v 50ah 3.36kWh Lifepo4 Battery 21s - $44/kWh
These batteries are built solid and the price is amazing. Easy access to the connections and all the balance leads are there. You can easily add a 21s BMS.
They were all recovered from all-in-one inverter systems where the inverter was locked out or non-functioning. The batteries are all perfectly balanced and testing at or near full capacity.
They are 55 1/2 pounds which is convenient because they can still ship ground. This avoids high costs of freight shipping.
We were able to break one of these down to 4s, 8s, 12s, and 16s but we had to use a dremel to cut the cell tab series connections. The module itself is very easy to dismantle just keep in mind the cell tabs are laser welded in series. You should have enough cell tab length to make a hole and use nuts/bolts for connections but overall we recommend keeping the batteries as they are and adding a BMS. These would also be great to put in series for higher voltage systems. Of course, high voltage systems require expertise and extra safety precautions.
You can see the wiring harnesses in the last 2 photos. Unfortunately, we couldn't afford a hand model this time since we're selling batteries for so cheap. The black wiring harness is all the temperature probe wires. That would likely not be useful for your application since your BMS will have it's own temperature probes. The white wiring harness is all of your balance leads. There is no model number on the wiring harness. You also get a main positive and negative wire. The main positive wire has an in line 50a fuse as you can see in the 2nd photo.
Each cell is 3.2v nominal and 50ah. Fully charged voltage per cell is 3.65v. Fully discharged voltage per cell is 2.5v. The whole battery nominal voltage is 67.2v. Fully charged 76.65v. Fully Discharged 52.5v. The pack is set up for max 50a charge/discharge (1C).
The main reason you don't want to break down these packs, as you can see in the photos, is they are professionally compressed and assembled. If you can't use these in the current configuration, we have plenty of other batteries in different voltages at great prices.