MKV Battery not holding charge

[Tony Soprano 1966]

Guys,I have yet another electrical problem on my Golf MK5,if I dont drive the car for a couple of days,battery is flat and I have to use a booster pack to start it.
Dont know if it is connected,but I had a rear ABS sensor replaced just before the problem started,although I had noticed before that was done, that it was starting to be bit slow to turn over from cold.
The battery is a Varta,and was new about 5 or 6 years ago.
Where do I start with this problem?alternator? starter motor? failing battery?
Or the dreaded parasitic drain?will post any VCDS DTC`S later.

 

[Henrick]

Parasitic drain. Someone here posted an excellent VW TSB on how to look for parasitic drain.

Meanwhile you're searching for that, this would be my suggestion (I assume you have a multimeter and know how to work with it).

Disconenct the battery negative cable. Use some clamp (hose clamp with adjusting screw worked fine for me) to secure one probe of multimeter. Attach another one to battery clamp. Set the multimeter to measure Amperes. Be sure to be using the "10A" slot and setting. How much current does it drain? Go and open/close a few doors of your cars, trunk, etc.... DON'T TRY TO START THE CAR as it will burn your setup. Then close the doors and trick the hood latch to "closed" position with a screwdriver. Press the lock button on the key, arm the alarm system.

Wait 5-10 minutes - drink some beer.

Then back to the car - how much current is it draining? Is it stable or changing?

 

[showdown 42]

Your battery is 5-6 yrs old? How long do you think they will last? Best way to find out is to charge the battery to full charge and LOAD TEST it. That will tell you if the battery is toast. 6 yrs is all you will normally get out of a battery anyway.

 

[Henrick]

Your battery is 5-6 yrs old? How long do you think they will last? Best way to find out is to charge the battery to full charge and LOAD TEST it. That will tell you if the battery is toast. 6 yrs is all you will normally get out of a battery anyway.

This is a very valid point. However, 5-6 years is not a verdict. Depending on how the battery was used and maintained, it can last up to 3 more years. In order to do a load test, you need to have special tester. Recharging battery is more easy option for average DYIer.

Remove the plugs of the cells. Check water level in each cell. Top up the water (with distilled water only!) in each cell - the plates should be fully covered. You can test specific gravity of each cell - the tester is quite cheap.
Use battery charger to charge the battery. Select lowest current available. Yes, it will be charging a century but that way you won't be damaging the battery which is already old.

Easy solution would be to get a new battery but I'd not recommend doing that before you rule out parasitic drain is not a problem. If it is, then it will kill even a new battery in days.

Old battery can still serve for some time. You just need to be more careful - always switch off your headlights before you shut down the engine, swicth off the cabin/dome light, switch off/take the key out of ignition as soon as you arrive - the radio also drains battery charge.

 

[soot1]

As Henrick suggested, start with measuring current draw from the battery. I went thru this procedure a few months ago - I hooked up the ammeter, shut all doors and locked the car. The engine hood was open. The current drain went down in several steps, starting at about 1.5 A, and ending at about 110 mA roughly 10 minutes later. I didn't have the patience to hold the leads any longer, so I don't know if this was the ultimate draw, but I was satisfied that 110 mA does not look like excessive drain. If your current drain is about the same, you can eliminate it as a suspect, and go straight for the battery. I realize I live in a vastly different climate than you do (much, much warmer, which shortens battery life significantly), but still, my original battery lasted only 4 years and 10 months. Also, the battery VW puts in vehicles sold in North America is not made by Varta, it is made in Mehiko by an unknown manufacturer. Nevertheless, if your battery is 6 years old and you have difficulties starting the car after a few days, it is, in my opinion, the most likely suspect.

 

[Andrewh]

While you can, start with testing draw, it is far more likely the battery is going and you should have it tested first before going to the rest of the trouble of checking for draw while down.
Also
here is the jist.

wire a 1.0 ohm 10 watt resistor in series with the negitive cable.
so one end of the resistor on the battery, one end on the negitive cable.

Take a volt meter and measure VOLTAGE across the resistor.

According to the article, due to ohms law, the actual voltage measures will be equal to the amps being drawn through the resistor.

 

[Henrick]

Well, that's the reason why I suggested securing the multimeter probes and getting some beer during the process.

110 mA is hell a lot. If it would stay like that, it'd kill your battery really soon.

After you lock your car, modules go do sleep mode one by one. It takes time for them to do that. That's why you need to wait at least 10 minutes. VW says you need to wait an hour but I didn't have a lot patience. Even after the modules fall asleep, they can awake due to shorts in the system or other factors...

VW specifies 20 mA is the maximum limit. I have seen a car which consumed 12-15 mA after 15 minutes being locked. Oh, and the car did also have an aftermarket alarm system.

 

[soot1]

110 mA is hell a lot. If it would stay like that, it'd kill your battery really soon.

110 mA load will drain a 72-Ah battery in 27.3 days, which means that a good battery should have no difficulties starting the engine after a few days even with this current drain.

 

[Henrick]

You're right. But bear in mind, that this is more than 5 times over the VW's specified maximum current for these cars...

Also, the battery has got 72 Ah when it's new and fully charged. The older it gets, the less capacity it has.

If you'd have secured your multimeter probes and had more patience, I believe that the drain would have dropped to the normal levels after some more minutes.

 

[JSWTDI09]

Here is the "official" VW TSB about troubleshooting parasitic battery draining.
http://pics.tdiclub.com/data/500/TSB_27_08_04_Matrix.pdf

Have Fun!

Don

 

[Henrick]

My bad. The limit is 40 mA and 2 hours. Please discard any numbers provided in my previous post.
Other than that, this thread already has got more than enough information to start troubleshooting.

 

[soot1]

I agree. Bottom line - alternator has nothing to do with Tony's inability to start the car. Neither does the starter motor, because he has no trouble starting the car with the help of a boost battery. Parasitic drain can easily be eliminated or confirmed by measuring the drain, and that's what I would try first. If that isn't the case, I would replace the battery as that seems to be the most likely, and the only remaining suspect.

 

[Tony Soprano 1966]

Thanks for the replies.I just checked for certain when I got the battery,as Varta`s are all colour coded,it was made in 2011,so 5 years old.I know some of you think thats its limit,but they are pretty durable,for example when I got this car in 2013,it still had the original Varta in from 2004,so had lasted 9 years,but I accept that this one may be on the way out after 5 years.According to the website,the battery cannot be opened to check cells.I will try to test for a drain,and rule that out.Got a few DTC`s,but they are all ones that have always been there-
1 Fault Found
17055 - Cylinder 1 Glow Plug Circuit (Q10)
P0671 - 000 - Electrical Fault
2 Faults Found
01552 - Motor for Central Locking; Drivers Door (V56); Lock
012 - Electrical Fault in Circuit
00928 - Locking Module for Central Locking; Front Driver Side (F220)
008 - Implausible Signal
1 Fault Found
00930 - Locking Module for Central Locking; Rear Left (F222)
012 - Electrical Fault in Circuit
1 Fault Found
00879 - Connection to Speaker Front Right
011 - Open Circuit

Have heard that the faulty door modules can cause battery drain>?

 

[Henrick]

Firstly, forget what the website says. Those batteris *can* be opened. Peel the label off and open the cells. Inspect water level. Add some, it will definitely need.

Check for parasitic drain then.

01552 - Motor for Central Locking; Drivers Door (V56); Lock
012 - Electrical Fault in Circuit
00928 - Locking Module for Central Locking; Front Driver Side (F220)
008 - Implausible Signal
1 Fault Found

^-- check your driver's door wiring harness inside the boot.

Finally recharge your battery and don't forget to share the results.

 

[Andrewh]

if that is the original type/manufacture of the vw battery, then yes they can be open. I did it to mine.

under the stickers are screwed in caps that you can pull out and see how much water is in there.

Us di water not tap.

but mine died right at 5 years and the replacement did too. literally just last week, 1 month from 5 years old it was reading 10 volts.

test till you find the answer and let us know.

 

[sptsailing]

Car's system is very sensitive to battery condition

Guys,I have yet another electrical problem on my Golf MK5,if I dont drive the car for a couple of days,battery is flat and I have to use a booster pack to start it.
Dont know if it is connected,but I had a rear ABS sensor replaced just before the problem started,although I had noticed before that was done, that it was starting to be bit slow to turn over from cold.
The battery is a Varta,and was new about 5 or 6 years ago.
Where do I start with this problem?alternator? starter motor? failing battery?
Or the dreaded parasitic drain?will post any VCDS DTC`S later.

In my experience with my 2006 VW Jetta TDI (manual transmission), it is very sensitive to battery condition. My 1992 Volvo 940 could function with a marginal battery. The Jetta cannot. I was having odd issues that made no sense. Replaced the battery and the odd issues disappeared. This Jetta came from the dealer with a solar battery charger, designed to leave on the dashboard and charge the battery through the 12v power adapter. This was probably done for the very reason that they knew the battery is supplying power to the car's electronics all the time.

 

[craig01b]

5 year battery life, might be short for some, but average for others. These cars don't like low voltage, and it could be a bad ground, tired starter, or a battery on its way out.

I can't see how a abs sensor could start this, probably just coincidence. Grounds are easy to check, a new battery will be in the cards once the summer ends..

 

[Tony Soprano 1966]

Ok,took some readings with multimeter connected and set to 10A,after locking car,(did not close bonnet) it was around 0.56,then some 10 mins later its hovering around 0.25-0.27,is that 270mA?? Is it time to start pulling fuses?

 

[Andrewh]

2 things.
first it is usually recommended to give it 30 min at least.
second there is a switch in the hood you have to close or it won't go to sleep.
if you can set up the alarm, then you wait 30 min and see what your readings are. if you can't set up the alarm you have to find the switch to close to let you.

 

[Henrick]

What Andrew said.
Ensure the hood is "closed" - the lock mechanism is tricked.
Arm the car and wait like 30 mins.

Do NOT pull the fuses. READ the TSB what is says. Pulling the fuses will give false readings as it will wake up the modules. Use the procedure described in the TSB.

270mA is like 10 times the expected norm. Measure voltage drop accross the fuses (as per TSB.. Can't stress this too much) to find out the offending terminal/module/element.

 

[Tony Soprano 1966]

Ok,how do you trick the hood mechanism..?

 

[Tony Soprano 1966]

Never mind,I found the hood switch and disconnected it.Hooked up multimeter,locked car,armed alarm, left for 30-40 mins.Reading now was 30-40 mA,so doesnt look like theres a drain?I had just given the battery an overnight charge @ 6 amps,it came off the charger at 13.30v.Pulled off the top sticker,and the thing is all sealed up,no way inside that.Checked the Varta warranty,on the blue batteries,which is mine the warranty is 4 years,doh missed it by a year,on the silver ones its 5 years,might get one of them next time.Does this mean the battery is on it`s way out do you think?I guess I could get local garage to load test it just to confirm imminent death..

 

[soot1]

Never mind,I found the hood switch and disconnected it.Hooked up multimeter,locked car,armed alarm, left for 30-40 mins.Reading now was 30-40 mA,so doesnt look like theres a drain?I had just given the battery an overnight charge @ 6 amps,it came off the charger at 13.30v.Pulled off the top sticker,and the thing is all sealed up,no way inside that.Checked the Varta warranty,on the blue batteries,which is mine the warranty is 4 years,doh missed it by a year,on the silver ones its 5 years,might get one of them next time.Does this mean the battery is on it`s way out do you think?I guess I could get local garage to load test it just to confirm imminent death..

Your drain is within the specified limit, so you can eliminate parasitic drain as a cause of your trouble. If you charged the battery overnight at 6A, and the battery still cannot start the engine if left for a few days, the battery is the culprit. Here in the States, dealers will load-test your battery for free, as it is a very simple test that takes only a few seconds. If dealers in your country offer the same service, it might be a good idea to have that done to confirm that it is, in fact, the battery, before you buy a new one. By the way, you lads in Europe are lucky you can buy the Varta brand, and choose among the various grades of the same size battery. My brother lives in the Czech Republic, and he tells me he only buys the top-line models from Varta, which last about 9 years in his geographic region.

 

[Henrick]

Yesterday I had a Golf Mk5 w. 2.0 TDI engine. The drain after 10-15 minutes was steady 0.25 A. It dropped down to 0.02-0.03 A after good 40-50 minutes.

 

[Tony Soprano 1966]

Update,ok if the drain is within VW limits,then the problem I have must be either battery,alternator or maybe starter?
I got local garage to load test the battery today,and they said the battery is fine,they also tested alternator and said that was charging the battery fine also.The only thing they could think maybe causing it is a failing starter motor.
Seems like a long shot but I guess it might be worth a try,as I still have that damn hot start problem,which many people report a new starter motor has cured.Thanks to all for your help,if I get this fixed will report back.

 

[Henrick]

Hot start problem is ECU/tune problem. It injects ZERO fuel at RPMs below certain threshold and coolant above certain temperature. This problem is widely know by the tuners and they have real fix for it. This is not actual starter/battery problem.