BTI Acer Extensa 5120, 5210, 5220, 5420, 5430, 5610, 5620, 7120, 7420 -10.8V, 4400mAh -6 Cells Retail Box 18 month warranty Product Description Need a battery for your laptop/notebook? BTI has you covered with this premium 6 cell 4400 mAh 10.8v lithium-ion battery . Manufactured by BTI and built to the highest quality standards, this battery meets or exceeds the original manufacturer\'s specific..