Audi A4 - Changing batteries

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Mon 24 Aug 2015 21:19
Audi A4 - Changing batteries - Steveieb

What is the best way to change over a battery?

Understand you must use a bridging battery to save the radio code obviously. But does the Central computer reset to factory settings if you don't bridge and is this not a bad thing anyway?

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Mon 24 Aug 2015 21:43
Audi A4 - Changing batteries - elekie&a/c doctor

Unbolt the old one,fit the new one.Do not use a bridging battery.This could be dangerous if the cables short out or touch the bodywork.The radio code should be stored in the car electronics.Nothing will default to factory settings.

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Tue 25 Aug 2015 18:21
Audi A4 - Changing batteries - Steveieb

Thanks elekie.

Can you explain how the cars electronics can store the radio code or is there none on the 2003 A4.

There are loads of postings on this site asking how to reset the radio code.

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Tue 25 Aug 2015 19:31
Audi A4 - Changing batteries - elekie&a/c doctor

A lot of the car info is stored in the instrument cluster electronics.Your car may be early enough to need a code input.You will not know until you reconnect the battery.The radio may show "learn" on the display when switched on,in which case it will take the code info from the cluster,so no need to input any digits on radio.

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Wed 26 Aug 2015 00:14
Audi A4 - Changing batteries - focussed

Don't forget - the negative battery terminal should be removed first and connected last.

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Wed 26 Aug 2015 09:33
Audi A4 - Changing batteries - Fernando P

You could get away with the assistance of a battery charger connected to the old battery terminals, which could be removed quickly from the battery. Then lift out the old battery replace it with the new, replace the terminals then quickly remove the charger. I used a CTEK (type) charger, and had no problems and the radio code setting was not disturbed.

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Wed 26 Aug 2015 09:47
Audi A4 - Changing batteries - elekie&a/c doctor

Replacing the battery on one of these can be a little awkward,as it is right at the back of the engine bay.However you could use one of these with a slave battery.www.tool-net.co.uk/p-366246/sealey-vs2072.html?gcl...Q

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Wed 26 Aug 2015 10:52
Audi A4 - Changing batteries - Fernando P

You are an asset to this forum, elekie doctor, as "you know your stuff"!

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Wed 26 Aug 2015 19:10
Audi A4 - Changing batteries - Steveieb

I second that Eleckie Doctor what a mine of information you have and all so positive. Thanks again !

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Thu 27 Aug 2015 07:38
Audi A4 - Changing batteries - madf

I use a battery powered memory saver.

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Thu 27 Aug 2015 12:15
Audi A4 - Changing batteries - Steveieb

Can Elecie Doc please advise whether it is safe to charge a battery in situ without damaging the ECU ?

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Thu 27 Aug 2015 14:35
Audi A4 - Changing batteries - elekie&a/c doctor

No problem at all,as long as a low current charger is used.Ctek chargers or similar are ideal for this.Don't use an old fashioned charger that you might have found in your dad's shed from the 1970,s.

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