car goes dead after 24 hrs of not driving.

kevincat · 06-19-2008, 08:56 PM

is it normal for a car to go dead after 24hrs of not driving. maybe sometime less than that. i have a mac mini and lilliput screen hook up onto a p1900v2.2. i have the deadmans timer so it would shut of if it get under 10.4 volts.

the car i have is a 350z. it has a fairly new battery so i dont know why this is happening.

sometime when i leave the car parked for 13-15 hours, the computer will shut off but the car will still crank. but if i leave it parked for bout 22 hours then it will drain my battery to a point where i have to jump start it.

i have a mac mini but i am running window vista where it has hybrid sleep. i heard that this doesnt drain battery that much.

it has happen twice already. is this common?? sometime i dont drive my car and just leave it park 1 or 2 days at a time and its such an inconvenient to jump start it every time.

please chime in guys....

colin · 06-19-2008, 09:39 PM

10.4v is pushing it... you probably can't crank after 10.4v, which is why it's dying.

You should have power to your computer completely cut when you're not using it. If you want to save your state, use hibernation. Do not run an entire computer (even in standby) on your car battery for more than... say... half an hour?

Most PSUs have appropriate settings for your car. If your car gets parked for 13-15 hours fairly often, youll probably want the power to cut after, say, 10 minutes. Your startup time is only a few seconds in most cases...

And lastly, why the hell are you running vista on a carputer?

billmee · 06-19-2008, 09:40 PM

Buy a meter and see how much current the mini draws in standby or assume it is too much and come up with a new plan.

Bugbyte · 06-19-2008, 10:18 PM

I used to be able to sleep my Mini for 3 days and still crank the car, so something is wrong. I also agree that your deadman timer should be set much higher. Try 11.4 volts or better.

First, do you have a lot of USB devices? Did you know the Mini supplies power to them when it is sleeping? GPS units, sound cards, etc. All are supplied power on the USB bus when the Mini is sleeping. Solution is to power the USB hub separately and use a piece of tape on the USB cord into the Mac on the 5v line to make sure it isn't drawing power from the Mac.

Also, I advise using a piece of software called Sleeptimer. You can set it to shut your Mini down after a certain amount of sleep. I set mine to two hours. I figure if I get out of the car for that long, I can wait for it to boot the first time I restart the car. At gas stops or store trips, it sleeps and wakes immediately unless I'm gone more than 2 hours.

kevincat · 06-19-2008, 11:57 PM

well the only reason why im running a carputer on vista is because of its vista hybrid sleep. it seriously start immediately after i crank the car on. xp doesnt have this option. by the way so far vista has ben pretty smooth ever since i used it.

im not good with meter and to be testing the voltage is out of the question.

bugbyte imma try to download sleeptimer when i have a chance. i think that is a good idea.

how could i set the deadman timer to a higher voltage.

ok and to answer the question about my usb......

i have 3 usb currently connected to the mini. one is to a extra monitor box that i believe stay on constantly. it will shut off if the computer is off and i have to press the button to turn it back on.

i have a usb imic connector to connect my car speakers and microphone to it. i dont know if it draws power. and the 3 usb is my touchscreen usb.

kevincat · 06-20-2008, 12:00 AM

hey bugbyte what do you mean to use a tape on the usb line... and also do i have to buy an extra 5 v adapter for the p1900 if i want to power the usbs separately?

kevincat · 06-20-2008, 12:04 AM

what do you mean by placing a piece of tape on the usb line. and do i have to purchased a 5v adapter for the p1900 if i want to power the usbs separately? can i just buy a hub and wire the usb hub to the car that way. is that the same thing as running the usb from the mini??

do you have the complete name of the sleeptimer. i found one but its called barry timer and it doesnt work the way you stated.

Bugbyte · 06-20-2008, 10:58 PM

Sleep Watcher is the name of the program but it is Mac. If you are running the Mini under bootcamp, it won't help.

As for the USB hub, if you wire it to the car, you will have to convert the car voltage from 12v to 5v. The 5v adaptor does this for you.

To ensure you aren't drawing power from the Mini when it is sleeping, you put a piece of tape on the USB connector over the 5v part of it. Or, you hack the cable and cut the actual 5v wire.

You HAVE to be good with a meter. Go to youtube and google up "how to use a multimeter" to find out how to use one. You'll thank me for this later.

Chairboy · 06-21-2008, 12:09 AM

That 'instant start' is why your battery is being drained. Choose between needing to call AAA and waiting 10-15 seconds to come out of hibernation.

kevincat · 06-21-2008, 02:02 AM

all excellent advices. thanks all