[Someone]

You don't care where your bike went, you care where it is, and you want a way to get that data remotely. The GPS only needs to be on when you call your bike, and that's where the problem lies: you have to find a way to decrease power usage of the GSM part.

Switching it on for a minute or so every hour if outside BLE range could help, but would make it harder to locate your bike fast. Maybe, it should start at a 100% duty cycle, and drop off over time? (Clock drift shouldn't be a problem. The device has GPS, so it has an accurate clock)

And you need to filter that 'motion detected' thing, or your bike will keep resetting itself, even before it can check the BLE connection. Or is that something that the sensor ICs can do for you, too, nowadays?

[walrus01]

I am pretty sure you could make a very, very low power watchdog circuit that only wakes up a GPS receiver and 2G/3G modem when it detects 60+ seconds of continual motion. Otherwise it'd sleep at very low power. This would fit in a $50 CF seatpost.

[Natsu]

Couldn't you power something like this from the bike itself somehow?