Lithium-ion laptop batteries have distinct advantages over the older nickel-based batteries. They allow for greater capacity and are low maintenance. The advanced technology includes built-in circuit protection and cell temperature monitoring. However, no battery lasts forever. If youre noticing reduced productivity from your computer, or if your battery is no longer holding a charge, you probably need a new one. Our replacement PA3785 battery for Toshiba Dynabook is built to the original manufacturers specifications for optimal performance, and will operate exactly the same as those direct from the factory. This 6-cell lithium-ion battery is rated at 10.8V with a 4400mAh capacity, and it is 100 percent compatible with the Toshiba Dynabook UK/24MBL, UX/23LBR and other models. See the product page listing of compatible laptops. One important tip to prolong the life of a lithium-ion battery is to recharge it when it reaches 20-30 percent of capacity, rather than waiting for it to be fully depleted. At USBPhoneWorld.com, we sell laptop batteries for many computer models, and our customer service team is happy to assist you with any questions.