Blueberry, if you still check in on this thread, where did you see that they (Qiroll?) say B70 batteries can be used with the Pro? I did message them and all they messaged back is the generic statement that the H70 is for the Pro and the B70 is for the Mute. I ended up buying a Pro and did try the B70 battery from my Mute just to see if it works, which it did but it was just a short test run. I'm planning on riding the Mickelson trail in South Dakota next week (weather permitting) and taking the B70 battery along as a power bank and as a standby for the Qiroll but don't want to run it on low voltage if it could overheat or otherwise damage the motor.