New Battery.

[bigman100]

Hi all,this topic has been flogged to death, but an answer has to be found. I have an Audi a4 2009 b8 2.0 tdi my battery is going fast, I need to know if I can change it myself, without a scanner. The net is divided over this ,I cannot afford for Audi to do the deed,so I need an answer. Your help would be much appreciated. Thanks. Ronnie.

[chan61922]

Recently changed the battery on my 2016 golf r, assume it’s the same scenario with yours. Manual states a dealer must do to register new battery and clear faults codes etc had the battery changed at Halfords, the donuts tried using a basic scanner etc, wouldn’t work! I know an odb Evelen and Carly is able to do. Suggested ring dealer, rang dealer they reckon they need to investigate issue to see if it is battery and if it were only they can clear the codes so book the car in and leave over night bla bla bla. I then YouTubed it on the spot and There’s a electrical plug/clip which is connected to the battery and goes back into the car, I disconnected this for a few secs and reconnected, I then drove the car around the block, hey presto all the fault codes cleared themselves, had to reset time etc but cars been fine ever since, this was probs 2 months back. Hope this helps

[bigman100]

Chan 61922 you have been a big help.Cheers.Ronnie.

[Adrian E]

You have a battery management module on the B8 - only way to convince the car it has a new battery is to enter a new serial number with VCDS etc, and disconnect the plug to the module at the +ve terminal at the time.

Find someone local with VCDS - most forums for VW/Audi models have a list of helpful folk that'll sort for a pint, at most.

I've been known to fit batteries and code for people without the skills/tools to do it, but depends if you're in W Sussex area! It takes a while to get to a B8 battery if you have B&O, and there's a lot of bolts to come and torqued back up on reassembly

[Who me ?]

As Adrian said - go find a VAG forum whre there's a VCDS register. I'D NOMINATE bRISKODA, where there's a rgister of members with VCDS. I's simply registr and ask. Friendly lot.

[colin_p]

Where are you, I could do it for some beer sheckles. East Berks here.

[chan61922]

Ignore everything everyone else says mate, you will be fine with my method

[chan61922]

Also to put the icing on the cake the tech at VW said this is what happens when people buy batteries from other manufactures or shops - it won’t work, only batteries from us work. Hahaha yeah okay mate! The rubbish I took out was some moderately powered (amp-wise) Korean rubbish called a sea bang- made me chuckle that lol

[Adrian E]

chan61922 said:

Ignore everything everyone else says mate, you will be fine with my method

You don't need to buy an OEM battery (my Audi doesn't have one any more) but you do need to amend the serial number stored in the control module for the battery management module to re-baseline the battery state of life (ie how aged is it) - you can just vary the existing one by one character and it does the job. It won't stop the car working if you don't, but you may end up shortening the life of the replacement battery and you certainly won't get the maximum benefit of a new battery.

[JuniorD]

This is really interesting. Does the same apply for the A4 B6?

When my original Moll battery went (at12 years old) I fitted a Bosch replacement myself, but this only lasted 2 years. It's replacement was the same - 2 years. Finally I had my local garage fit one (Yuasa) and 3 three years on - everything seems fine. I assume they did any necessary VDS business?

[chan61922]

Hmm Didn’t know that, either way the battery I got comes with a 5 year guarantee, any probs I just hand it back and get a replacement, that’s the case with most batteries now if bought from a half decent place (no eBay etc) so I wouldn’t really worry about it. Just ball ache having to leave vehicle with dealer for them to come back with a ridiculous price for a replacement anyway. But sure if someone can code it for a pint of liquid gold then fair play, think OP isn’t looking for too much hassle nor does he want to pay stupid dealer prices

[Adrian E]

JuniorD said:

This is really interesting. Does the same apply for the A4 B6?

When my original Moll battery went (at12 years old) I fitted a Bosch replacement myself, but this only lasted 2 years. It's replacement was the same - 2 years. Finally I had my local garage fit one (Yuasa) and 3 three years on - everything seems fine. I assume they did any necessary VDS business?

Hiya

That pre-dates Audi fitting battery management modules, I think - think the first was the D3 A8 and it then filtered down the range over time. Don't think the B6 architecture was much different to the B5 in electronics terms? I don't recall needing to do it on my C5 A6 BITD.

Coding info is covered here, for anyone who wants to dig into what's required

http://wiki.ross-tech.com/wiki/index.php/Battery_R...

Quite often when you buy a battery off the shelf from eg Halfords they don't have accurate details for the capacity (how much juice it stores) nor the CCA (how hard it can crank the juice out when turning a cold engine) to advise on the correct one for your specific example, so you can end up with an under-spec'd battery - ECP are really bad for this too if you rely on vehicle registration look up. They're often only half charged on installation, so if you do a lot of short runs in winter you can quite quickly kill a new battery. I always go for the 5 year warranty batteries where I can, just for peace of mind. Got a Yuasa in my S5 at the moment, and seems to be holding up well - it's the 3rd battery in the car since it was built in 2011. If I can I'll charge the battery before fitting too - takes the load off the alternator trying to top it up when in all likelihood you've changed it in winter because it's died and are running around with lights on, heated seats etc etc.

Just an example of load - was updating the nav on my S5 yesterday, so popped the battery charger on while it ran. it takes 2-3 hours. At its most active, the charger was pumping out 11A to partly top up the battery and deal with the drain caused by the HDD running constantly.

If you do a lot of short journeys and/or leave the car unused for weeks at a time, it's worth sticking a maintenance charge on the battery occasionally to stop it draining too deeply. Less of an issue with stop-start capable batteries as they're able to cope with greater fluctuations in charge state, but the one in my Golf is tiny so gets the same treatment if it's locked away for weeks at a time. The charger gives a 0.8A trickle on demand (a reasonably economical Ring branded one)