the blank screen/resume feature is great, and i love using it during the day for stops and what not, so much better than the old way. but its not too much work if the car is gona be sitting more than a day to just unplug it. it would be amazing if we could just plug it in and leave it forever. but we have to remember, most of us bought this just for tuning and some data logging. so these added features are an awesome bonus IMO.

When it happened to me, my car wasn't sitting not being driven though.
I drove back and forth from work which is about 10 miles each way.
I think it was maybe the 4th day when my car wouldn't crank.

in just one night?

Over the course of 3 days.
Back and forth from work each day with OFT plugged in the whole time.

ahh i see what your saying. yeah, best bet is like you already are doing, just unplug it over night. its a pretty mild tune, unless your tracking there's no need to monitor it every time you drive the car anyway. I only use mine if ive made changes, or if im gona be driving hard/tracking.

Yeah, it's not a big deal.
I had it mounted perfectly to leave plugged in though :D

This is why I've been trying to source an OBD extension with a built on switch. There are a few online but they're not cheap...

Would probably be cheaper to just buy an extension and splice a switch in yourself. Battery power is on Pin 16, which is the lower right most pin if you're looking directly at your OBD2 port on the vehicle (narrow side down, wide side up).

This ^, I was wondering the same thing. It would make sense if the ecu normally goes into a standby mode when the car is off, but when I leave it on the datalog screen it always has up-to-date info from all the sensors, so maybe it is constantly sending/receiving when the oft is plugged in.

Yup, I've got a few extensions on the way, I'll experiment later :) now to find a good spot to house the switch...

Perhaps the fact that the OFT is talking to the ECU keeps the ECU awake?

That would make more sense than just the OFT draining the battery.

The light dimmer panel on the left side of the driver underdash panel is a good candidate. Can remove that whole panel from the underdash panel and work on it with unlimited access. Snap it back together and route the wires along the back of the panel, good to go.

Yes, that is what I was referring to rather than OFT flattens batteries by its own power draw.

If you go through the trouble of making a custom cable with a switch, just take Ignition power and route it to pin 16 of the OBD-II connector instead of Battery.
Then the OFT will only get power when the car is on.