Amazon calculates a product’s star ratings using a machine learned model instead of a raw data average. The machine learned model takes into account factors including: the age of a review, helpfulness votes by customers and whether the reviews are from verified purchases.
I just moved to australia from north america and my old trusty oral b charger would not work her cuz of the voltage difference. I decided to buy it again here. Got a great deal for 18$ and it works just like my old trusty used to. The charge lasts about 5 days and i usually have to charge it every weekend. This isn't the high priced professional ones but imo it does the job its build to do pretty well. I'm glad the oral b quality continues to hold up