3 ms·I guess you mean why every doctor doesn't own 2-3 of these, because battery won't last a day...by Elhana 13y agoI guess you mean why every doctor doesn't own 2-3 of these, because battery won't last a day...mkr-hn 13y agoThat's what the power cover is for.Teckla 13y agoThat's what the power cover is for. And now it's too heavy to carry around all day every day.