This was a terrible product. I tried everything to get it work better: I made sure it was fully charged, cleaned the filter and emptied it, made sure the battery was inserted correctly, etc., and it still never worked well. Every now and then the battery would miraculously work for a few minutes at full power--and I never figured out how that happened. We gave this thing many chances over a year period, but most of the time the battery would last for 15 seconds and then die. I ended up throwing it in the trash out of sheer frustration. Save your money; buy a better product.