Lenovo 5B11M90090 is an internal lithium-ion battery for a compatible Lenovo laptop, intended to power the computer from inside. Its part number is associated with battery model L21M6P70, identifying this particular replacement configuration.
The battery has six cells and a 94Wh energy rating, which describes its stored energy capacity. Its listed voltage is 11.52V, and the safety data sheet gives a weight of 375g. These details can help identify the correct part when servicing a laptop that uses this battery assembly.
As an internal component, it is distinct from an external power bank or removable accessory. It is intended for replacement inside a compatible laptop when the installed battery needs to be changed.