Hill Gradient Suddenly went "WONKY"
Posted: Wed May 28, 2008 10:33 am
So I was out for my first "real" ride with the boys this morning hoping to impress everyone with my iAero, but unfortunately something went wrong with the device part way through the ride and from that point forward the device was showing that I was climbing anywhere from a 5% - 12% grade when I was actually on flat ground, which of course gave me ridiculous power numbers (upwards of 1000W sustained, which would make me super-human if true).
It was a cold morning to start the ride, around 38F. I let the iAero sit outside for a good 20 minutes prior to the start, verified the tilt calibration (it was within 0.1%) and did a good wind offset calibration. At about 50 minutes into the ride, the power numbers started spiking to ridiculously high values, whereas to that point they were good. I had "auto-hill" turned on so I immediately saw the problem since it started flashing to me that I was climbing when in fact I was not.
I checked the battery voltage and it was showing 250 - 255. I guess the cold air caused the voltage to drop. I turned the iAero off and back on, and for a brief moment it showed correct gradient but quickly reverted to showing me climbing, so I just left it and ignored the numbers from that point forward.
After getting home and getting the device up to room temperature, the battery was still showing 255 but the gradient was showing correctly again.
Do I have a "lemon" iAero? Would low battery voltage cause a tilt error like this? I thought I read that low battery may cause wonky wind numbers but I don't remember any mention of tilt errors.
It was a cold morning to start the ride, around 38F. I let the iAero sit outside for a good 20 minutes prior to the start, verified the tilt calibration (it was within 0.1%) and did a good wind offset calibration. At about 50 minutes into the ride, the power numbers started spiking to ridiculously high values, whereas to that point they were good. I had "auto-hill" turned on so I immediately saw the problem since it started flashing to me that I was climbing when in fact I was not.
I checked the battery voltage and it was showing 250 - 255. I guess the cold air caused the voltage to drop. I turned the iAero off and back on, and for a brief moment it showed correct gradient but quickly reverted to showing me climbing, so I just left it and ignored the numbers from that point forward.
After getting home and getting the device up to room temperature, the battery was still showing 255 but the gradient was showing correctly again.
Do I have a "lemon" iAero? Would low battery voltage cause a tilt error like this? I thought I read that low battery may cause wonky wind numbers but I don't remember any mention of tilt errors.