this be a replacement for a slightly different , older model Dirt Devil that last for year & give I good service . the model I now have be purchase in May 2010 and have not be use much . I use it very infrequently , mostly on my computer . I have a problem with this newer , improve model . when I press the `` on '' button it come on strongly , but within a few seconds lose power so much that it will not vacuum dust up . but , if I press the `` on '' button harder , or shift the point of maximum pressure to a slightly different place on the `` on '' button , the power get stronger , but then quickly subside to a low level . the result be that it be frustrating and essentially I can not usefully vacuum with it . it drive I nut as I try different way of press on the `` on '' button in a attempt to vacuum something up , and it just want to run in a very low power way that can not vacuum even dust up . I be guess that the battery be not the problem , but rather the problem be something to do with the `` on '' switch . I do not know . I send a email to the Dirt Devil people . if they take care of this problem I 'll post that info . otherwise ... maybe I just get a lemon ?