The best toothbrush ever, but wears out completely in 2-3 years. [SEP] Excellent cleaning of our teeth, great results when we get checkups and keeps our teeth feeling great.  It would get 5 stars except you must replace them about every 2-3 years, they just slow down and poop out(have had 3 or 4 of them).  I do run the battery down occasionally, like the instructions recommend to keep the battery memory effect down. From the manual &#34;To maintain the maximum capacity of the rechargeable battery,unplug the charging unit and fully discharge the handle with regular use at least every 6 months&#34; Your Iphone does not recommend this.  If OralB (Braun) wanted to they could use a cell phone type of battery, ie lithium, and the lifespan and power would be MUCH better, but no its just an old tech nimh-hi (says so on the unit).  So great brush but meant to wear out pretty quickly.  Also the replacement brushes are very pricey, they have to be about 5 to 7 dollars each.