14x 3.7v 4750mah 17.57Wh Cells with BMS - $60/kWh

These batteries have all been removed from overstock or customer returned Amazon tablets. The BMS is a 2a BMS and it connects to a connector. These packs you can charge and discharge from the red and black wires. If you check the voltage on the red and black wires and get 0v just apply a 4.2v 1a charge. Many of these batteries are sitting at 2.8v and the BMS discharge kicked in. Takes a second to reactivate. The 2 red wires are positive, the 2 black wires are negative, the 2 white wires do nothing for your build so just cut them out. Super easy to build packs with these. The backs likely will have some "wrinkly" appearance because they were double side taped down but the cells are super sturdy, no swelling at all, and we've tested hundreds of these and they test amazing. Most of these have never been cycled or only cycled a few times.

Of course we always recommend using a BMS on all battery packs. If you make a higher voltage battery out of these and find a way to connect to the ribbon connectors you should always use an overall pack BMS. These BMS units would work great as smart cell level fuses.

These sell for $15 per battery on Ebay. Model 26S1014 for the Amazon Fire tablets. You are getting 14 of them.

Dimensions are roughly 1/8" x 3 7/8" x 4 3/4"