It is a Ni-MH battery which has a capacity of 3800mAh. It is a 14.4V battery that has been made with the help of high-quality cells, and it is compatible with iRobot Roomba 400 Series. The battery will give the Roomba a 130 minutes run-time. It is convenient to use, and it is a high capacity battery. It can be charged only with the help of Ni-MH and Ni-Cd chargers and not with a lithium charger. The battery is easy to install, and it fits perfectly in the vacuum cleaner. There are some features which protect the battery from short circuit, incorrect voltage, and issues of internal overheating. It will let your Roomba work efficiently with cleaning everywhere on the floor. When we compare Powerextra battery with others, it is observed that after 30 days of full-charged storage, other batteries discharge rate is 40% while the same for Powerextra is 30%. Powerextra batteries perform better than the other batteries when they are given the same range of voltage. Its capacity remains 10% higher than the other batteries available in the market. The dimensions of the battery are 5.7 x 2.7 x 2.5 inches while its weight is 1.6 pounds.