B7 TDi Dead battery after 10 days away!

[Guest001]

Yes, ...or as simple as a faulty battery.

Yes well as I said Battery world quoted over $800 for mine which is the Bluemotion model so he might need to save his pennies LOL

[Sam2012]

Yes well as I said Battery world quoted over $800 for mine which is the Bluemotion model so he might need to save his pennies LOL

The car was only purchased new in May, I would hope this will be covered under warranty.

[Transporter]

The car was only purchased new in May, I would hope this will be covered under warranty.

From my experience, the VW battery warranty is 3 years (coverded under the vehicle warranty).

[Sam2012]

It was finally taken to the dealer to have the battery and systems assessed. The service department told me that the battery was at full capacity when the car was dropped off and that the battery was draining within limits (draining at 0.008amps when locked). The car may have had a very low battery just before it was parked and locked in the garage. They said no errors were logged with the systems computers.

I was told that if the battery drains like this again to bring it in and they will have another look at it.

Thanks again to everyone for the feedback it has helped and I hope this will help someone else in the future.

[Cossor]

I note that VW make a big deal of the battery being charged when braking.
"Energy recovery"
So how does this occur?
New V7 Golf now has this feature, and in addition, freewheels down hills!
Once again, how to ensure battery is charged to capacity?
For example, trip from Sydney to Melbourne. Cruse control on. Night time, raining. demisters on!
If dependent on brake input may not be able to cope!! ???
Bit of a worry, as about to give Golf to Son, and purchase 125TDI Passat

[booba]

the car will still have an alternator wouldn't it?

I note that VW make a big deal of the battery being charged when braking.
"Energy recovery"
So how does this occur?
New V7 Golf now has this feature, and in addition, freewheels down hills!
Once again, how to ensure battery is charged to capacity?
For example, trip from Sydney to Melbourne. Cruse control on. Night time, raining. demisters on!
If dependent on brake input may not be able to cope!! ???
Bit of a worry, as about to give Golf to Son, and purchase 125TDI Passat

[Cossor]

the car will still have an alternator wouldn't it?

One would certinly hope so.

But how is energy recovered during the brake cycle?

If free wheeling down hill, then engine RPM minimum
Ditto during braking, assuming Bluemotion DSG disengages motor

So how does it work? I can only envisage standard alternator with very smart decision algorithim.
OR external alternator perhaps on the rear wheels, used in conjunction with engine alternator.

BTW, Driving Commodor in rain, stop start traffic, night, AND with rear demister on. Battery failed at que near lights.
Dead lucky, was NRMA vehicle one car behind me. Got jump start and limped home. Battery tested OK, Car in use every day.

[MJW]

My understanding is that the car monitors voltage & makes a determination if the energy re-generated from the braking is sufficient to maintain minimum safe voltage & if not then the alternator will kick in as per normal.

I believe the energy generated from braking is more than the alternator for the same period of time. Also note that the less the alternator works, the more usable power you have & saving on fuel.