BCD436HP/BCD536HP: Auto Power-ON Trick - For Car Use

[kandrey89]

So I figured out how to start my radio when I start my car automatically by accident.

The scanner has to my knowledge an undocumented last power state feature.

How to use:
1. drain batteries (to ~2.9V as measured by the scanner and do not recharge them)
2. plug into car's USB port
3. turn on the scanner and leave on
4. turn off the car
5. the scanner will turn off abruptly without saving anything to the uSD card (any settings changes you make would be erased but preferably for a static setup you don't need to save anything anyway, otherwise just power cycle the scanner using the button to save the changes before letting the car do the power cycling for you)
6. turn on the car
7. the scanner will turn on by itself because it was abruptly shut down
8. make sure you're using the latest scanner firmware that has the 10 or 15 seconds prompt wait time before skipping the prompt that asks you if you want to connect in storage mode to the USB (it's not necessary but useful if you forget to press the NO button)

I've done this at least a dozen times already, no microSD card issues. I always turn on record mode and those recordings are unaffected. I wish Uniden would stop being asshats and make a proper firmware version so that the power on state and record mode state on startup were controllable through the options, and also be able to get rid of that storage mode prompt (setting the timer to 0sec) and adding an option to put the device in storage mode through the options menu.

I allowed my batteries to drain fully because they don't charge when I use my radio and since I only use it during my drive and listen to it all the time there's no time to charge, and that's how I discovered that my radio would turn on by itself.

 

[fxdscon]

The Home Patrol 1&2 have always worked that way for last-state at power up.

The trade off is that you do lose some functions without the batteries, such as recording.

.

 

[cellphone]

Unfortunately the radio requires charged batteries to record, and I cannot give up that feature. I have my 436 wired to constant power and leave it powered on all the time. I hit menu to stop it from scanning when I exit the car. When I get back in, I hit menu again and it picks up right where it was left and I don't have to wait for it to boot. Not automatic, but the best solution I have found.

If I want to leave it recording while I am out, I turn the volume all the way down.

 

[kandrey89]

Unfortunately the radio requires charged batteries to record, and I cannot give up that feature. I have my 436 wired to constant power and leave it powered on all the time. I hit menu to stop it from scanning when I exit the car. When I get back in, I hit menu again and it picks up right where it was left and I don't have to wait for it to boot. Not automatic, but the best solution I have found.

If I want to leave it recording while I am out, I turn the volume all the way down.

Opps, you're right, forgot to test the removed batteries, I'll ammend my original post to just say drain your batteries to ~2.9V and then the scanner will turn off on external power off but will still allow you to record with low batteries on external PS.