Something is draining your battery.
If you disconnected power to the PC, then that's obviously not it.
What draws power with the ignition off?
Time to get out the multimeter...
Put in new battery 3 days before leaving for a trip, drove for those 3 days fine, then leave car on driveway for 7 days with radar and carputer UNPLUGGED, come back to dead battery
maybe it is hte lilliput, it goes into the stand by mode blue for 5 secs after car is turned off howver after that it shuts down to black screen so that cant be it
7 days x 24 hrs/day = 168 hrs. If something is drawing 250mA, thats 42Ah. Depending on the size of the battery, that could be a significant portion of the rated capacity and cause it to discharge to the point where your car won't start. The Lilliput probably isn't completely off. I thought I saw something here that said at least some of the Lilliputs drew more the 250mA when "off". Do a search on the forum and you should find more information.
Kind of off topic, but I have an old army surplus vehicle with a switch that disconnects everything from the battery. It will start after 2 or 3 months of sitting. None of my more recent Toyotas would do that with nothing but the stock equipment in them. Alarm systems and keyless entry systems all take current so you've got to use your vehicles reasonably often or you drain the battery. And that seems to be really hard on the batteries too.
could it be that the carputer is not grounded properly? even if the carpc is turned off?
It's impossible for us to speculate as to what the problem is. Your best bet would be to install a current meter inline with your battery (with the car off) and see what kind of load you are drawing at idle (make sure all dome lights are off).
The generally acceptable amount of idle current is <50mA, but I generally like to see less then 35mA.
If you are over 50mA start uplugging aftermarket stuff first. If you still have a high load you can start pulling fuses, one at a time, until you find the fuse that disconnects the load.
I've read about OEM stereos in certain cars having internal issues that keep them powered up, killing the battery rather quickly.
tomorrow I will run some tests with everythin on and some parts off and so on, and will let you know how it turns out
I can pretty much guarentee it is the lilliput.
I have a lilliput and what you describe is not off. It is standby. Standby means that it will auto-on, but also means you have to drive the car every 3 or 4 days or you are doomed.
I leave mine on all the time. When I go on vacation, I pop the hood and disconnect the negative terminal of the battery. Come back, screw it back on, starts right up.
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