Stay unplugged longer with these genuine ThinkPad batteries. These rechargeable batteries use Lithium-Ion technology and can be used as replacement for aging system batteries or as a convenient spare battery.• Lithium-Polymer-Technologie • 4-Zellen-Systemakku • Akkuenergie (Wattstunden): 29 Wh • Kompatibel mit dem externen Ladegerät von ThinkPad (40Y7625)