Tiguan Battery Issues

[Shaker]

My wife has a 2009 Tiguan diesel, the battery was replaced about a year ago & often seems a little "soft" on first start of the day. This morning it actually failed to start, battery registered 11.93 volts after the attempts to start it, after starting it, I again checked the voltage with it running at 1500rpm & it was 14.00 volts.
I spoke with our local auto electrician & his first question was, do we lock the car? We live on a country acreage & never lock our cars, although we do remove the key from the Tiguan so that the radio turns off immediately. The auto elect said that if it's not actually locked the computer doesn't sleep & continues to use power, is this correct?
Thanks

[MGV]

I have heard this is correct, however, i never locked my car when it was parked in a locked garage (mainly) & mostly only driven weekends & the battery was good for 5 1/2 years. I think it's the 'luck of the draw'...

[Umai Naa!!]

It will still go to sleep after 20mins or so, as it would do if you locked it.

They go through a couple of stages of shut-down, to the point of being 'asleep' though.

If it's waking back up again, that's a problem that's not always easy to solve.

[Transporter]

So, did you test the battery?

[Shaker]

Not yet, will get it tested today.

[lukeallison]

I work for Battery world the guy is correct you much lock your car for the computers to sleep. The cars computer with shut down after 20mins however the car will continue to look for the key until the car is locked so you must lock your car



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[Shaker]

Not yet, will get it tested today.

I had it tested & it appears that it is down on cranking capacity.

[Hillbilly]

Have just been through this with my Passat New battery in October, going flat over 2 weeks when not being used. Car in garage unlocked. Got sick of having to charge it so started testing it daily and was losing .2V per day. Had car in garage with key pulled and unlocked and bonnet open. Have 2 dashcams and a HUD all connected to ACC fuses. Nav just shuts down with ign.
Took it to dealer for a battery test. Perfect!!!.
They tried it over a day with it both locked and unlocked and Nav off with ign and off manually. Same result.
Only thing I did wrong was didnt push the little lock in the bonnet catch across thereby the ECU realising the bonnet was open. Does draw current apparently.
Since i have it back have flicked the bonnet lock and tried it locked with Nav off manually and unlocked with Nav off with ign and only losing .01-.02V for last 9 days. So it seems as long as everything is shut it doesnt make any difference. Foreman said the ECU would normally shut down within 20 mins except when bonnet or a door lock was open.
Reading was 12.74V on 28/3 Now is 12.57 this morning.

Will see what happens.

[spyder]

Hi,
I have a 2012 Tiguan Bluemotion 6 speed manual. Last week the Stop/Start....well, stopped working.
While the car was stationary at the lights, it just disengaged and stalled.
Had the Battery tested at Battery World, told me the CCA is down by 2/3. It's an OEM Battery and 6 years old.
At the moment the Tig seems to start ok, but just wont engage the Stop/Start anymore. (I know most people would be jumping for joy )
Maybe a no brainer, but as they are not cheap, a new Battery is the order?