If you own a Toshiba Satellite U300 laptop and need to replace the battery on this device, the number that you need to remember when ordering a new battery is PA3594U. This is the part number of the original Toshiba battery used on these laptops and when you search for replacement batteries at USB Phone World, using this number will allow you to locate the ideal battery for your Satellite U300 series laptop computer. Our battery replacements for model number PA3594U 1BRS original batteries are 6-cell units that have a capacity of 4400mAh and a voltage of 10.8V. Our batteries are priced much lower than retail and the quality of our batteries is very high. In fact, you can expect slightly better performance from our battery than the original Toshiba battery. Charge times are slightly longer and recharging the battery will take less time, due primarily to the advanced lithium used to make our batteries. You can be assured that our batteries are compatible with your laptop and our claim is backed by our 30-day money back guarantee. We also stand by the quality of our replacement batteries by adding a 12-month warranty to our products.