This pic (posted by Erick L) showing a battery with no juice is familiar: I have noticed that when starting-up the bike, if the computer screen showed this, I'd end-up experiencing some of the power drop-outs commented on, by others: e.g., on a hill, Turbo mode would be disabled (Sport mode, too), as the system would revert into Eco mode. There appears to be some sort of glitch with the software (perhaps future firmware updates will resolve this). I'm hoping that future firmware updates will resolve the issue. Meanwhile, I have found at least one sure-bet way of avoiding the problems (and maybe a second way, too.)
The first seem analogous to the need (with some computers and cell phones) for regular reboots, with the system then running again like new, after the reboot. To accomplish this full reboot, I'd typically need to do two things: first, remove the battery; second (while removed), use the reset button on the back of the computer. (You can then replace the battery.) I'm not positive that both of these actions are required, nor about the importance of this particular order. I just know that whenever I'd do this, the system would then run like new. I got into a habit of doing this at least once a week, and it completely eliminated the problems. (As it happens, I need regularly to reboot my phone, too.)
I'm less certain about a second way of avoiding the problems, as I've only been trying this for a couple of weeks, now. Here, the point is always to remove the computer when charging the battery. I don't know why that would matter, but so far it seems to have helped. (I haven't yet ruled out that in fact it hasn't helped at all, and that the apparent success is owed to the first of my solutions.
Putting to the side this pesky issue, this is an awesome machine! I've got a little over a 1000 miles on my bike, and I absolutely love commuting with it.
