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Discussion Starter #1
I followed a post I found about diagnosing dieing battery issues. I have a 2000 TDI and it has an overnight battery discharge issue. As this is a deisel and it is cold on Wisconsin nights, I need all the CCA I can get. I pulled the car in tonight and with the ignition off and the doors unlocked it had a drain of .18 amps The DMM actually spiked when I hooked it up (as high as .64) but always came back down to .18 amps. It was posted that .15 would kill your battery in 11 days or so. Is my .18 amp drain normal? Is this causing my problem? I took the battery out and took it to my NAPA dealer (where I bought it) and the battery itself tested out as good. 12.67 Volts and 746 of 750 CCA. The car will charge fine once started and will restart without issue after having run for 10 minutes or so, I am thinking battery drain, but I expected higher than a .18 amp drain. Thanks for any help you can give me.
 

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Troubleshooting

BATTERY DISCHARGE
The normal parasitic drain on the battery of a Beetle or Jetta is 0.05 to 0.06 amps. This drain occurs when any door is closed after the rear hatch. For some reason, the battery drain is as much as 0.075 amps if the last "door" closed is the hatch and not a passenger or driver door.

Anyway, any drain of 0.18 amps is not normal and it will eventually lead to a low battery state of charge which means the failure to crank and start the engine. The original amp-hour rating of your battery is around 72 AH for a TDI battery. Overnight, a 0.18 amp discharge will net you a 2.2 AH loss (amps times hours). In one whole day it amounts to 4.4 AH or 6% of your battery's capacity. Since your battery certainly won't start your car below 60% of its total capacity (43 AH), its important to find the source of the battery drain.

I strongly suggest that you keep a charger on your battery while it's parked overnight until you find the source of the battery drain. Even a trickle charger will completely counter act the battery drain until it's located and fixed. It will also prevent permanent damage to the battery which will occur if it is continually left in a partially discharged state.

A drain of 0.18 amps is typical of a single 12 volt relay that is continuously energized in the vehicle. I assume that you measured this battery drain by disconnecting the negative battery cable and inserting the DVM between the battery terminal and the cable when the meter is set to measure amps. If so, the reading should be reasonably accurate. Make sure that you confirm that this drain is constant thru at least 4 or 5 minutes after the meter is hooked up -- not just 30 seconds.

A lamp in the glove box or in the hatch area will draw more current (at least 0.3 amp) so that type of load cannot be the problem. You can attempt to isolate the offending electrical load by removing individual fuses in the in-dash fuse panel until the battery drain drops from 0.18 to a stable 0.06 or 0.05 amps. You can also begin by removing relay 109 (load reduction relay) under the dash in the thirteen fold relay panel. Note that any relay that is energized continuously will be warm to the touch. So just touching relays in the panel can tip you off that one of these is energized. In addition, there have been problems with the radio when the amp section of the monsoon radio does not completely shut-off causing battery drain. Pulling the radio fuse can isolate this problem.

It is possible that the parasitic current draw is from the alternator. If this were to occur, pulling fuses won't locate the problem. This is not the most likely source of the drain, and removing the large cable from the 6 mm stud on the back of the alternator can verify or eliminate it as a source of the problem (engine off and your ammeter connected).

Also, think of any modifications to the electrical wiring or the addition of a new accessory that may have been done to the vehicle in the last month or two. A new radio or fog lamps, etc. It's possible for a mod to create an unintended continuous battery drain.
 

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Discussion Starter #3
I found the drain. If I pull out the fuse to the interior lights, I get a drop to a steady pull of .06 amps. This is fuse number 14. Any idea where the relay might be that is energized? Is that going to be above the drivers feet or elsewhere? Any idea which one? I am a bit discouraged with the Chiltons manual I have. It shows you what the car looks like but that is about it. I didn't even find a fuse diagram in the thing.
 

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The fuse S14 powers the "Central Control Module for Comfort System" (module J393). This module is under the instrument panel, left of the steering column. This module receives input from the keyless remotes, controls the anti-theft alarm, interior lights, and has an interface to the door control module via the vehicle Can-Bus.

I assume that the interior lights do not work properly with S14 removed since the wiring diagrams for the Beetle show that these lights receive power thru S14. When S14 is in the fuse panel, does this vehicle have any problems associated with remote keyless entry? Any problem with the alarm going off or failure of the doors to lock and unlock properly? The Central Control Module directly powers the illumination for the remote trunk release. Check to see if this light is going off with the vehicle is shut-off. Also, the module directly powers the rear hatch locking motor. Does the hatch open and close properly with the use of the remote unlock button?


Under the driver side dash is the 13 fold relay panel. There are two standard 15 amp fuses at the top of this relay panel. One is fuse S144 and the other S111. S111 is the anti-theft disable fuse and the other, S144, is the fuse for the anti-theft warning system. It would be interesting to know if the battery drain disappears if either of these fuses is removed while S14 is back in the fuse holder.
 

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Discussion Starter #5
You are correct that the interior lights do not function when the fuse is pulled. Neither does the remote lock/unlock and I assume the alarm does no activate as the red light next to the lock does not blink. I will check the trunk light but I think that the fuse on that housing has been blown for awhile. I know it doesn't light.

Everything appears to work normally when the fuse is in, with the exception of said trunk light. I assume the light you were talking about checking to see if it went off was the trunk release button backlight and not the actual trunk light. Is that correct?
 

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Yes, the light on the release button should be checked, not the light in the trunk area. Please check the current drain with fuses S111 and S144 pulled.
 

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Discussion Starter #7
Are S111 and S 144 marked somehow? I have not yet pulled the kick plate off to look at the relays. Or are they the only two that are there?
 

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Fuse Positions

There are 4 fuse positions above the relay panel. From left to right, the first position should be vacant, the second is the power windows fuse S43 (30 amp), the third is S111 (anti-theft 15 amp), and S144 (anti-theft alarm horn 15 amp).
 

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Great write up on what seems to be a problem I'm having.

I'm about to go through the 3rd battery in about 2 years. Didn't seem to be having any problems with the car and then boom a 3 year warranty battery dies in 1.5 years (was drained after sitting a week without starting), the next battery in 8 months (single digit degree morning in Feb), and this one is only 3 months old right now. I'm pretty sure its on its way out as it takes a little longer in the mornings for her to start, same symptom as the last 2. Here's the catch... When number two died I took her to the stealership and told them that I was having premature battery deaths. They said they checked the charging system and checked for drains and found nothing. They blamed the battery and charged me 200 for parts and labor to put it in (that doesn't count the 80 to analyze the problem. So now that this on is on the way out what should I do? Do I need to wait for it to die to take it back to the dealer and say "Hey this battery is 3 months give me a new one and find the leak."? I'm just afraid they are going to come back and tell me again that there isn't a leak.

Went out and purchased a $30 Radio Shack multitester. Its rated up to 0.2A (200 mA) so I figured it would be sufficient to determine if there was leak according to this write up. Sure enough it kept maxing out. Started to pull fuses, but apparently my multitester didn't like to keep getting maxed out and I think I blew the 0.5A fuse cause it won't read anything anymore(voltages, resistance etc), which would lead me to believe my drain is closer to the 0.5A range. Apparently Autozone can't test for draining so looks like I'll be taking it to a shop of some sorts.

In the meantime I'm simply undoing the negative terminal at night to at least prevent further damage.

Thoughts, opinions
 

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Sorry to hear that there are more Beetle owners with battery drained problems. As you see in my previous posts, I encourage anyone with these kinds of problems to get a battery charger connected to the battery overnight. Disconnecting the battery will eliminate the drain, but it won't recharge the battery. Don't expect the alternator to recharge a battery - it's designed to maintain a charge. You may not drive long enough to get the battery recharged. Batteries are ruined by remaining in a discharged condition for long periods of time.

Battery parasitic load problems are one of the last things a dealership wants to deal with. Anything that takes troubleshooting time is frowned upon. Replacing a battery and closing the hood and then giving you the keys is preferable to finding a drain on a perfectly good battery. As an electrical engineer for a company that makes starters, alternators, etc, I can appreciate your problem. The Radio Shack multi-meter should have a replaceable fuse so the meter is not likely to be permanently damaged. It is likely that the battery drain is significantly more that 0.2 amps. This drain current is in the range of a lamp load like the glove box lamp or the rear hatch lamp. Check to see if obvious lamp load drains are not the problem (including the rear brake lamps). It is also possible that the drain is intermittent and the dealer never noticed the problem because it was not happening when they had the car. As an example, I have found a problem with a car that had an intermittent battery drain. It turns out that the brake lamps would stay on sometimes when it got really cold outside. At any other time the lamps would not be on. It was caused by a defective brake switch. Good luck in your search for the cause…………………………..
 

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2010 VW Beetle Battery Drain

I recently purchased a a used 2010 Beetle 2.5 for my daughter with 38,000 miles. If the car sits for more than 3 days, the battery goes completely dead. I found the fuse was blown on the 12V power points which I'm going to replace today but I can't believe that would be the cause of the drain. Any thoughts or insights are appreciated.
 

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battery

It almost sounds like a bad battery. Is the car a turbo? In turbo cars the aux coolant pump runs for 10-15 minutes after you turn off the ignition and sometimes the relay stays stuck inside the fan control module and could run for hours draining your battery.
 

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I'm having the exact same problem with a 2006 beetle. The alternator and battery are both perfectly fine, but the battery completely drains after 2 or 3 days. Currently searching for the source of the drain, and I understand why dealerships don't like doing this kind of work.
 
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