Lenovo ThinkPad 9 Cell Lithium Ion Battery 44++ ( Manufacturers P/N; 0A36307 ) 94Wh Extended Life System Battery For X220 And X230 Laptops Only Only Used In Lenovo X220 And X230 Laptops. Not Used In X220T Tablet Or X230T Tablet Lenovo 9 Cell , 94Wh, 510 Grams, 9.0Ah , 11.1V Extended Life Battery ThinkPad Lithium Ion Battery 44++ Has Over Discharge Protection. Lenovo Battery 44++ Is Safeguarded With A Chip To Authenticate Itself With Lenovo Systems. Lenovo Battery Reset May Be Needed If Your System Is Not Recognizing The Item With An Error Warning. Remove And Re Install The Item To Fix This Issue. This Is Due To Recent Windows Updates. This 9 Cell Extended Life Battery And Will Stick Out Of The Battery Compartment By 1 inch.