Review on XOSS X1 Bike Speed and Cadence Sensor: Wireless Bluetooth 4.0 Computer for Accurate Bicycle Speedometer (2 Pack) by Timothy Louis

Two of these sensors, purchased together, each drained four brand new Duracell batteries in seven or eight days with only 25 actual minutes used per day. They don't seem to have a standby mode; Once installed on the bike they connect to my phone or Xoss GPS bike computer after 24 hours of no handlebar movement. The claimed battery life of 300 hours (taken as "working hours") is greater than the roughly 200 hours the batteries last whether they're moving or not. I was able to figure out a faulty sensor; two with the same failure modes indicate design, manufacturing, quality control, or all three at the same time. I wish I had known this during the return period but I hope this review will save someone else from making the same mistake.