On the B8 A4 it has battery management so you are supposed to program the details of the new battery in using VAG-COM ,Especially if you change to a different battery. If you stick with a battery of the same or similar spec it's not so critical.
Check the dimensions and capacity of the battery fitted.
Karl.
The coding of the battery isn't entirely essential as long as the battery you fit is the same size / capacity as the existing battery.
My car has a 110Ah battery as standard. I replaced it with a Varta I1
http://www.ebay.co.uk/itm/Varta-I1-Van-Battery-12V-Silver-Dynamic-Battery-/281843348620?
If you were to upgrade the battery you would need to recode the new one so the Battery module is aware of the capacity of the new battery.
http://www.audizine.com/forum/showt...cated-is-it-to-replace-the-battery-on-a-B8-A4
There are some conflicting reports of people having issues when they don't change the battery code in VCDS. But I would bet some of those people have other issues with alternators or batteries being drained due to issues with the car. Also if you let the battery state get really low the battery module doesn't seem to recognise the new battery.
That is an excellent and informative post, thank you.My car has a 110Ah battery as standard. I replaced it with a Varta I1
http://www.ebay.co.uk/itm/Varta-I1-Van-Battery-12V-Silver-Dynamic-Battery-/281843348620?
If you were to upgrade the battery you would need to recode the new one so the Battery module is aware of the capacity of the new battery.
http://www.audizine.com/forum/showt...cated-is-it-to-replace-the-battery-on-a-B8-A4
There are some conflicting reports of people having issues when they don't change the battery code in VCDS. But I would bet some of those people have other issues with alternators or batteries being drained due to issues with the car. Also if you let the battery state get really low the battery module doesn't seem to recognise the new battery.
My only concern is if I just replace the battery without the recode, what would the behaviour of the car/battery be.
The “official Audi” manual suggests a course of action which would result in you having to go to an Audi dealer to buy a “special” Audi battery with a VAG part number which would then be “notified” to the ECU with “special” VAG software so that everything would run perfectly again. Audi aren’t going to deviate from this stance and give alternative, pragmatic advice. Ultimately it’s your decision for your car.
I took a personal decision to put an aftermarket battery in my car and I don’t have access to any VAG software and everything worked (and is still working) fine. Personally, I believe it’s just a simple marketing ploy to get business as ECUs spend their whole life “adapting” to changes like new alternators being fitted, higher & lower octane petrol, higher altitudes, differences in air temperature etc – adapting to these changes does not need a laptop to be plugged in.
However, modern cars do have sophisticated electrics and so I agree that it is sensible to pick a replacement battery which has identical specifications to the original.
Your battery is certainly well past it's best then. An OEM battery should be good for at least 5 years and typically 7-10 years if you are lucky.What would you call 'last legs' @desertstorm ?
I know mine is on its way, pretty sure it is the original. I measured 2 months ago 13V when the engine is on, and 10-11v when off..
So my dash cam switches off within a an hour now when the car is off where as before it would last 4 days, the power unit is set to switch it off when the volts are less than 11.95.
Your battery is certainly well past it's best then. An OEM battery should be good for at least 5 years and typically 7-10 years if you are lucky.
When a battery reaches 12V it has around 30-35% of it's capacity left. That's open circuit voltage. You are measuring the voltage with a small load on it so if you were to disconnect the battery from the car the voltage would increase but not by much.
I replaced the battery in my car last year it's an 08 with 100K on it so the battery was around seven years old. It wasn't as bad as yours and wasn't showing any major signs of any issues until we went away on holiday for a week.
Car was parked in the airport multi storey for a week, came to it and when I went to start it the engine was very very sluggish when being turned over. Another few days and it probably wouldn't have started at all.
With the winter ahead I decided to change the battery. It probably would have made it through last year OK as it wasn't that bad. But I intend to keep the car for several more years and I want it to be reliable so I would have to be replacing the battery at some point. Rather do it in my time and get the best deal possible rather than having to run around to Halfords and buying something sub standard and paying 50% more for the privilege.
Winter is on it's way now and the cold only makes the situation worse for a failing battery. Having a battery with low capacity has knock on consequences for other parts of the car, as the alternator has to work a lot harder. And the large voltage variations can cause issues for all the complex electronics in the modules.
If you intend to keep the car for another 2-3 years then you may as well change the battery now and get the best out of a new one.
I presume that was a petrol. With diesels the starting currents are a lot higher and with glow plugs and all the electrical loads on modern cars you wouldn't get away with that.
Just changed mine... no issues
Doesn't look like an OE battery and doesn't look that old either judging by the date code. I am assuming the date of manufacture is 14/04/2014.
How long have you had the car ? .
You can work out the original size of battery supplied in the car by looking at the PR sticker.
http://prsearch.planetvag.com/
Wonder if the car was sitting around a bit before you bought it and the battery went down. If an older battery is left to go completely flat it can kill it. Strange that you are having battery issues though if it is a fairly new battery.
Is there not a sticker on the front/back/side of the battery?
Sent from my E6853 using Tapatalk
*edit*
After checking the pr sticker, my original battery spec was J1U - battery 450A (95 Ah)
The G3 blue Varta is pretty much the OE spec battery. The silver dynamic the upgraded Item. If you are thinking of keeping the car for a few years I would probably pay the extra and get the silver dynamic. Especially if you will be leaving the car standing for periods of time.
Either are good batteries.