No need to disconnect battery, the PP82DSP supports hot swap. The disconnection of the battery is suggested in the PP82DSP manual as means of safety if you are wiring this unit yourself to the battery directly. This 100% PnP BimmerTech PP82DSP kit is already wired for you and it does not require any direct battery connection.
Technically the OEM amp 12V power line is not switched. It is a controlled line based mainly on the status and timing of the opening and closing of the doors and trunk. The ignition controls the permanency of the 12V as a secondary trigger. The 12V will go to
sleep (less than 1V) after 20 minutes or so after all doors/trunk are closed and ignition is off.
All this means that the 12V line will be constant only after opening a door/trunk if more than 20 minutes has passed after the car has been sitting, locked and off.
The PP82DSP actually turns on by signal sensing. Which also means that, although "constant" 12V are present, the unit itself is not on until it senses voltage at its inputs. There is voltage in the inputs any time the iDrive unit is on. And the iDrive turns on by opening a door/trunk, and turns off (0V at the outputs) after 5.8 minutes after closing all doors/trunk in the F30.
Quote:
Originally Posted by sandwi54
You do not need to disconnect the battery if the ignition is off. The 12V that powers the amp is a switched 12V. I also verified this by trying to connect the amp to my laptop while the ignition is off, and a connection couldn't be established, so that means the amp was not powered.
Even if the amp's 12V is not switched, I wouldn't worry about plugging it in directly as the $800 amp has to have a hot swap controller to soft-start the 12V input.
|