Tested Valence U-Charge U1-12RJ LifePo4 Battery 12V 40Ah 512wh

Every battery is fully tested and comes with the printout of the test report which shows the capacity and charge/discharge graph. You can select the tested capacity from the drop down menu. There is a BMS already built in to each battery.

If you want to series connect them you should charge each module fully then connect in series. You can also parallel them. These are one of the most trusted and best built batteries on the market. They are used in many hospitals. Bolts are also included.

You can series up to 4 to make 48v modules.