M1-ATX Killing battery over night?

**linkyone** · 02-06-2007, 09:20 AM

i have had my car pc installed for over a year and for the last couple of weeks my car has had trouble starting, ive changed out batteries and had my alternator tested (everythings good). i hooked up a multimeter to the car, inline, and tested the amps when the pc is off. its pulling 9mA. is that normal? i didnt test it when i first installed it and have nothing to reference to. can someone be so kind as to put a meter inline and see how many amps they pull when the pc is off? thanks a bunch, when i get back to the states ill buy you a beer!

Edit: ok i just hooked up the computer again and now i see it in standby with 115.3mA. but still with a 910 cranking amp Optima battery, i dont see how it can kill it over night!

**guizai** · 02-06-2007, 12:04 PM

Sounds like your M1 isn't performing the hard off option anymore. I think the draw is suppose to be like 5mA max when the car is off.

**JimmyFitz** · 02-06-2007, 12:07 PM

You should be able to leave the PC in standby (Suspend To RAM) without killing your battery. 100 mA is not unreasonable, a car alarm may draw up to twice that much while just sitting there watching for intrusions.

Here is another thread where STR current was given by several folks:
Optimal Boot Speed Hibination Suspend modes.

You need to see if the PC is really the item draining the battery or maybe something else. An electrical problem with some other part of the car could be the culprit (stuck relay, stereo amplifiers, defroster, etc.) Disconnect all power to the PC overnight to see if it makes any difference.

Another common problem that is frequently overlooked is bad connections between the alternator & battery, or battery to ground. Good luck.

**linkyone** · 02-07-2007, 04:40 AM

guizai: I have the power supply set to not perform the hard off function because i put the pc in standby when the car shuts off.

Originally Posted by JimmyFitz

You should be able to leave the PC in standby (Suspend To RAM) without killing your battery. 100 mA is not unreasonable, a car alarm may draw up to twice that much while just sitting there watching for intrusions.

Here is another thread where STR current was given by several folks:
Optimal Boot Speed Hibination Suspend modes.

You need to see if the PC is really the item draining the battery or maybe something else. An electrical problem with some other part of the car could be the culprit (stuck relay, stereo amplifiers, defroster, etc.) Disconnect all power to the PC overnight to see if it makes any difference.

Another common problem that is frequently overlooked is bad connections between the alternator & battery, or battery to ground. Good luck.

I agree with you, 100mA is nothing! I disconnected the ground and hooked up a multimeter. nothing but this 100mA total. i retightened the battery wires and the distribution points. the only place i have to check on is the alternator. i have pulled the pc out of the car and the car has been fine since. it doesnt make any sense. i have had this carpc installed for a year and now the problem arrives. i havent changed a thing. i have the computer hooked up in my office with both a volt meter and an amp meter running. hopefully in this controlled enviroment ill get an answer. if this thing doesnt kill this extra battery in the course of a couple days then i am going to have to rule it out and start all over again.