14.4v 6.6ah 95.04wh Li-Ion Module with BMS
Around $80/kWh for packs with a BMS!
Here are awesome Panasonic 4s3p 14.4v 6.6ah 95.04wh packs with a working BMS. The positive and negative wires allow charge and discharge current so you can use these packs as is. I would recommend keeping the charge and discharge limited to 3 amps per pack or 0.5c. The two blue wires are just for the temperature sensor so you don't need those 2 wires. Just cut the positive and negative wires off the connector and those will be your main wires.
Cells used are Panasonic CGR18650CG which are excellent cells trusted by the medical industry. These are used medical packs with different dates but mostly around 2013 dates. Either way they were only used as backup so the packs likely have not cycled too many times. If you get a pack that does not read voltage simply apply a charge and they will wake up immediately. The cells may be sitting just under the BMS low voltage cutoff. The packs can charge up to 16.8v so just set your charger to 16.8v and maybe 1-2 amps and these will take a charge.
There are 3 options of usage for these packs.
Use the packs as is - Charge up each pack to 16.8v, connect as many as you want in parallel to make a nice 14v pack. Most inverters will take up to 15.5v so at this price, even if you can only charge up to 15.5v to work with a 12v inverter, you can build a 12v pack for a fraction of the cost of anything else out there with a BMS, especially since charging this pack to 15.5v you should get around 80% capacity compared to charging up to 16.8v but many studies show you will more than triple the cycle life by undercharging that amount.
Use the cell configurations as is - Simply remove the shrink wrap and the BMS. You will have cells in 4s3p configuration. You can easily configure these into higher voltage packs. For example you can series 3 of these packs into a 12s module. Then cut one module in half to make a 2s3p module. That way you can make a 14s3p module using 3 1/2 packs.
Salvage the cells - You can also salvage the 12 cells out of these. Remove the shrink wrap, the BMS, wires, and nickel. I would recommend saving the BMS, wires, and nickel for scrap because you can recover some scrap value out of those boards or even sell the 4s lithium ion BMS
Each module weighs 19.5 ounces (1 lb 3.5 oz)
Packs are 4.5" wide, 1.5" deep, 3" tall. Wire leads are roughly 2.5"
Pack full charge voltage is 16.8v
Pack full discharge voltage is 11.2v
The 4th photo shows one of our tests, we tested a few hundred of these and they all test very well with most in the 6.6ah range after a 2nd cycle. This can give you an idea on the discharge curve.
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| Brand: | Panasonic |
| Model: | CGR18650CG |
| Capacity: | 2250mAh Rated |
| Voltage: | 3.60V Nominal |
| Charging: | 4.20V Maximum 1500mA Standard --- mA Maximum |
| Discharging: | 3.00V Cutoff 430mA Standard 4330mA Maximum |
| Description: | Green (Light) Cell Wrapper White Insulator Ring 18650 Form Factor |