Battery powered vacs

The short message that I have is JUST DON'T BUY THEM. First of all they will not last the length of the warranty and second the length of the warranty is NOT necessarily what is printed on the sticker. I truly believe that this is not legal !  I had bought two hand held Dirt Devil units with "ACCU CHARGE" technology that were, according to the sticker warranted for three years. They both were useless after around two years. I called the customer care center on two occasions about two months apart and ended up with two "new?" replacements. The two replacements became useless after about 6 months, and so, because the three year original warranty period was still not up, I called again but now they wanted the original bill, but because I could not produce the original bill (something that I was not asked for when they were replaced the first time) the warranty became a date that they had somewhere and was not anywhere on the original labels, (I kept a photocopy of the original labels) and guess what, the new date was just earlier enough to mean that without the original bill the warranty was past. Sneaky business to be sure when the warranty is clearly marked on the label. Well my original hundred plus dollar investment plus the two free replacement units, that's four vacs, could not give me service for the three years that the warranty stipulated on the tags. That's four strikes, enough for me. My advice is to stay away from Dirt Devil battery powered vacs.