I am a (Very) happy new Prius owner with an Android phone and an Elm 327 Bluetooth OBD scanner. In my previous car (Citroen C4) I had my scanner plugged in constantly, and only unplugged it when I wasn't using the car for more than a week, and I never had any issues with battery failing etc. Question is, how would the Prius handle this? I am reluctant to leave it plugged in due to all of the issues with recharging the battery using jump leads etc if done incorrectly. Information purposes, it is a 2008 (58) UK T-Spirit with original battery and 33k miles, most trips approx 5 miles long. Regards Jordan
I leave my ScanGauge II plugged in all of the time and have never had an issue with the battery to date.
ScanGauge goes to sleep nicely when the ignition is shut down. That doesn't tell us whether or not another vendor's Bluetooth device does the same.
I've had mine plugged in for 2 weeks straight w/ no issues. The Elm 327 has an led on it that tells you when its off. I have noticed that the led goes out when you turn the car off. I don't see it being an issue. The ELM 327 doesn't do much but transmit the info to your phone and receive the info from your phone (low power draw).
If you are going to leave your Prius set for several days (10 or more) I would recommend unplugging it and turning off your SKS (if you have it). Otherwise I would not worry about it.
The ELM clones and probably even the genuine ELM article may not power down so I would be careful. An alternative is a unit that uses the STN1101 part or a scanner from Scantool.net which uses that part. Another is to use a USB powered scanner that is Totally powered by USB power. When you disconnect the USB cable the power draw goes away from your tablet or Laptop, putting the laptop to sleep also works but I would not advise leaving your laptop in your car. The Bluetooth gets you away from a cable but the scanner is now totally powered from the OBD2 port's 12V pins ( the tiny Prius battery )
