Electrical gurus....My cars battery always drains somehow. I have tried multiple batterys and they all go dead within like a day. My alternater is fine and its charging. What the hell. I think I have some kind of draw. Is there any possible way to track a voltage draw. This is driving me crazy.

First, check the obvious things such as lights that are staying on. The trunk light is a possible culprit, you can check that by looking through the rear seat pass-through.
To test for current drain, disconnect one of the battery terminals and connect an ammeter between the cable and battery post. With the engine off, key out and doors closed the drain should be in the tens of milliamps. If it's in the 100ma range or more that is an excessive drain. Since your battery is dying within a day it may be even higher, maybe a few amps.
To find the source of the drain, begin disconnecting things by pulling fuses and/or unplugging individual devices while watching the meter. When you disconnect the device or circuit that is causing the drain you'll see the meter reading drop down to normal.
The first things you should try disconnecting are any aftermarket devices you have installed (stereo, alarm etc.) that are connected to full-time power.

Now all those methods make sense, but I am wondering just how safe it is to pull out all those fuses. Some of those are connected to things like air bags. I am concerned about pulling those out in case they decide to deploy or act out is some undesirable way. :confused:




Here is one method I was able to google:

"Here is the procedure we use to isolate a battery drain. Remove negative battery cable from the battery.

Using a 12-volt test light, hook one end to the negative battery post the other end to the negative battery cable you just disconnected. The test light will glow or "light" if there is a drain. If the "light or glow" is faint, that is probably normal draw for the clock or computer. If the "light or glow" is bright, then there is a large drain. That should be corrected. Now start removing and replacing the fuses one by one until the light goes out; that one will be the circuit with the drain. Remember to hold in the button in the door jam for the interior lights."




Another article I googled:

New cars perform vastly superior to vehicles built only a couple decades ago. A major factor in this has been the advancement of electronics in almost every automobile system. One drawback to this advancement though, has been the extra load placed on the automobile battery.

Each electronic device on our vehicles uses a "little" electricity even though everything may be turned off. On-board computers are the biggest users of the electricity, but any device with a "memory" built into the program requires current (power from the battery) to keep the memory set. Fuel injection computers, climate control computers, keyless entry modules, lighting computers, digital radios, clocks, memory seats, and trip computers all have memories in them, with many of them programmed by the driver. The constant drain on the battery to keep these memories operational is what can drain a battery if the vehicle is stored for a few weeks.

Other electronic devices also put a drain on the battery. Alternators, voltage regulators, and ignition systems use electricity even when not operating. Diodes, one way electrical gates located inside these devices, are supposed to prevent the flow of electricity through these parts when the systems are turned off but a small amount of electricity can leak through the diodes. Fortunately, the electricity that leaks through a good diode is very small and it would take several months for this drain to kill a battery.

Testing for excessive current flow from the battery has changed along with the automotive electronics. It used to be sufficient to place a test light between the battery post and the disconnected battery cable. If the test light came on, there was a battery drain on that vehicle. That test no longer works for smaller computer drains. The only correct method of testing for a battery drain is to use a digital ammeter.

The ammeter is connected between the battery post and the disconnected cable just as before. This meter measures the actual current flowing from the battery into the electronics systems. A typical engine computer will use between 5 and 8 milliamps (thousandths of an amp) to keep the memories working. Most vehicles should show a total reading of 25 milliamps or less when the test is performed, however a few luxury cars may show as high as 50 milliamps. In comparison, a trunk light uses about 900 milliamps or .9 amps and would drain the battery overnight.

If the measured current flow is too high, then fuses are disconnected one at a time until the faulty circuit is identified for repair. Some vehicles will require a waiting period of up to 1/2 hour before an accurate measurement can be taken. During this time the computers are "awake" and use more power. After sitting for several minutes without any switches being operated the computers go into "sleep mode" and use less power.

Take caution if you try testing the current flow; opening a door (which operate the interior lights) or turning on the ignition switch or headlights will damage many ammeters. The testing must be done carefully to prevent high current flows from passing through the meter.

Many of the newest cars are using electronics to reduce the risk of having a dead battery. Some cars such as Lincoln and Cadillac monitor the battery voltage and begin to turn off systems if the battery voltage goes below normal limits. This helps those that tend to leave their lights on or park their vehicles for long periods. Other vehicles have timer modules that monitor ignition switch position and turn off the power to interior lights and other accessories after a preset time. The owner's manual will describe this feature, but if you don't have it, using a 2 amp trickle charger will keep the battery fully charged when the vehicle is sitting for long periods.

Finally, other factors can cause a battery to go dead faster than normal. Warm temperatures cause the battery chemical reactions to occur faster causing the battery to discharge quicker. Dirt or dust on top of the battery and high humidity levels also cause a problem. The electricity leaks through the damp dirt directly from one battery post to the other causing the battery to discharge. Keeping a battery clean, cool, and dry will ensure it retains its charge longer.



Hope this helps!