SP4, 3x12v10Ah. It was working fine, I rode it home from work yesterday, charged the battery last night. Turn it on today, nothing. Well, not nothing, the throttle LEDs light up, and when I test the battery with a DMM I get 39.8v, and there is a high pitched whine that ramps up in pitch until it's nearly inaudible when the battery is first connected. There is no response from the throttle. I tried disconnecting the brakes and no difference.
I'm also unable to connect the USB. First I connect the USB, then start the software, set COM and hit connect. Wait for timeout and apply power then it connects. Sometimes. Sometimes the timeout window pops up repeatedly many times a second, sometimes it connects but when I try to download changes to the controller I get a timeout error.