I put the Lenovo ThinkPad X220's 24-hour battery claim to the test | Windows Experience Blog
Just bought a quirky x220 slice battery. Looks exactly like a 19+, but says 20+. Works completely fine with 1% wear. Does anyone know what it might be? : r/thinkpad
The Slice Battery for ThinkPads (🍕🔋 🍀 🤔🗒️) - YouTube
the slice battery was too expensive, but i had a better idea : r/thinkpad
ThinkPad X220 versus ThinkPad X230 with 19+ battery slice | Flickr