Can you fit an EFB battery yourself?

[gord115]

The battery on my sons VW Polo gt has gone.
He has been told he can fit a new one himself by his father-in-law who is a mechanic.

The shop who sold him the battery also says this.

When the battery went on my Golf R i was led to believe you couldn't fit one yourself and you had to have the battery "Configurated to the system".

Who is correct?

[generationx]

I had to fit a new battery to my Giulia - it lit up every warning light possible. A quick scan/reset with a cheap (Amazon) OBD reader fixed everything.

More relevance: a friend has a recent-model Passat and fitted a new battery with a similar “every warning possible” result. He consulted a mechanic friend who said, as was proved correct, that after a decent 10/15 mile drive the car “learns” the new battery and all the warnings go away without any intervention.

I’m not a qualified mechanic by any means but these are my real-world experiences.

[gord115]

Well, he fitted it himself and has had no problems at all so far.

[CLK-GTR]

Some cars need to have the battery coded to the car because the the energy management system alters the charge and usage according to current battery condition. If your battery degrades to say 70% the car will adapt to that, the car needs to know a brand new battery has been fitted so it can alter the battery profile. You might end up with electrical gremlins otherwise.

[Glosphil]

CLK-GTR said:

Some cars need to have the battery coded to the car because the the energy management system alters the charge and usage according to current battery condition. If your battery degrades to say 70% the car will adapt to that, the car needs to know a brand new battery has been fitted so it can alter the battery profile. You might end up with electrical gremlins otherwise.

As said above.

Car system not informed of new bsttery = battery charged incorrectly, which may shorten its life

[Smint]

How come the car can 'learn' to manage an ageing battery but can't 'learn' a new one without a fee changing hands for recoding?

[CLK-GTR]

Smint said:

How come the car can 'learn' to manage an ageing battery but can't 'learn' a new one without a fee changing hands for recoding?

My understanding is that it can but in the time it takes to learn you will have already done irreversible damage to the battery.

[OldGermanHeaps]

A capable vag knockoff diagnostic cable that can reset the battery among lots of other useful things is 20 quid. Why stress about it and just do the job properly?

[gord115]

Well so far no problems, but if he did within the battery's warranty all he has to do is take the battery back and exchange it.
After all it was the supplier who said he could fit it himself.

[ohreally]

I'm sure if like for like was fitted he will be fine going forward. In some instances the BMS may need updating but hopefully not in this case.