As an interested BBS02 user I was very disappointed in the data provided by my 500C display. I already had my speedo that provided all the usual speed and distance data and found that it was difficult to read the more interesting power and voltage on the little display - and the voltage was off by 0,6V. I changed to an Eggrider to get the programmability features which worked well but this display while providing many valuable features is even harder to read. To solve this problem I added a simple power meter. This little device uses an external shunt that is mounted between the battery and the controller. I mounted the display on the top tube near the stem - not the neatest but very functional. The display provides an independent reading of voltage (V), current (A), power (W) and energy WH). The energy section is resettable. I have found this device to be extremely valuable. It is easy to read, provides accurate data and most importantly allows for an easy determination of riding efficiency (wh/km), At the start of a ride I just reset my speedo and the power meter energy and have the data I need to calculate efficiency. It is also easy to determine actual battery capacity - I use it to monitor SOC on long rides - easy and very accurate. They are available at Amazon or Aliexpress for < US$20.