Potential Parasitic Draw 2003 2.5L
- Thread starter Z4Will
- Start date
Very old post but someone may find this usefull?
Just as a note, if you disconnect the earth NOT positive and put a multimeter on 10Amps range (note connections to the meter for current measurement are usually different to normal Volts Ohms etc) between earth and the earth terminal ie. the meter becomes the earth lead then you will trace dark current (this is spurious draw that can flatten a battery) note also, if your battery is 80Ah then it will take an 8A draw to flatten it in ten hours or 16A in five hours etc to kill it. Most courtesy lamps are 5W so 5=12 x X, X being Amps so about 416mA draw from your battery so it would take 190.5 hours or so to flatten your battery to a dead state. You also need to know that a battery that can't start a car is not necessarily flat, just unable to supply sufficient current to turn the starter motor. DO NOT start or try to start the car with a meter in circuit, you will destroy the meter, most have a maximum current capacity of 10A! Run the meter cables out of the boot and close it. Lock the car and watch the meter. If it stays on zero after the draw for locking, change to a lower range, usually 400mA and see if anything is reading now. Normal is up to about 50mA with everything off and locked. This will be alarm, clock, etc.
Just as a note, if you disconnect the earth NOT positive and put a multimeter on 10Amps range (note connections to the meter for current measurement are usually different to normal Volts Ohms etc) between earth and the earth terminal ie. the meter becomes the earth lead then you will trace dark current (this is spurious draw that can flatten a battery) note also, if your battery is 80Ah then it will take an 8A draw to flatten it in ten hours or 16A in five hours etc to kill it. Most courtesy lamps are 5W so 5=12 x X, X being Amps so about 416mA draw from your battery so it would take 190.5 hours or so to flatten your battery to a dead state. You also need to know that a battery that can't start a car is not necessarily flat, just unable to supply sufficient current to turn the starter motor. DO NOT start or try to start the car with a meter in circuit, you will destroy the meter, most have a maximum current capacity of 10A! Run the meter cables out of the boot and close it. Lock the car and watch the meter. If it stays on zero after the draw for locking, change to a lower range, usually 400mA and see if anything is reading now. Normal is up to about 50mA with everything off and locked. This will be alarm, clock, etc.
I never lock my car when its in the garage as I think setting the alarm will drain the battery in due course. I have disconnected the bulb in the boot as I leave the lid up a bit for the trickle charge leads. Are you sure its not one of the bulbs staying on which is draining your power.
