@JamesSM

Active Member
Jul 26, 2013
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The manual says the new Leon has either an AGM or EFB (these seem to be also called ECM) battery fitted - does anyone know which one is fitted in the Leon 1.4TSI FR?
I had a look the other day under the cloth cover and all I could see was Exide Spain. Looking at the Exide website it seems their AGM batteries are colour-coded blue and the ECM ones have grey writing/labels on.

I'm a bit concerned as my battery was the latter colour yet the Exide site says that the AGM is the correct one for my car given the Regenerative Braking technology.
 
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It's nothing fancy. Just an ECU controlled switch that disconnects the alternator electrically until you press the brake pedal or the battery voltage drops to the point where it needs charging again.
 
My 1.2TSi + DSG has an EFB (Enhanced Flooded Battery) 69Ah Part No 6R0 915105B

Interesting. Does it say Exide Spain on top? According to the various websites I've visited, they all say that AGM batteries are required because my car has Regenerative Braking (Energy Recovery System).

Your 1.2 has the same technology as far as I'm aware. AGM batteries are obviously a bit more expensive - are SEAT cutting corners here? :confused:
 
Our 1.8TSi has a 69Ah Varta EFB battery. I won't be losing any sleep over this as I am fairly certain that every car built in the Martorell plant has regenerative braking and if the factory was being supplied with the wrong batteries then someone would have spotted the error long before they were fitted on the production line. ;)
 
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AFAIK all Mk3 Leons have regenerative braking.

Seems that I am wrong on this one, my apologies.

Regenerative braking, in the strict sense and as used by the battery manufacturers, is not the same as brake energy recovery.

The former describes electrical energy recuperation from a traction motor (e.g. hybrid vehicles) and the latter describes recuperation from the alternator under braking.

This explains why our cars are fitted with EFB and not AGM starter batteries.
 
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Seems that I am wrong on this one, my apologies.

Regenerative braking, in the strict sense and as used by the battery manufacturers, is not the same as brake energy recovery.

The former describes electrical energy recuperation from a traction motor (e.g. hybrid vehicles) and the latter describes recuperation from the alternator under braking.

This explains why our cars are fitted with EFB and not AGM starter batteries.

Thanks. I'm not sure it explains though why in the owners manual it says the battery will either be AGM or EFB (note: it mentions AGM first) and the fact that if you type your registration into any of the Battery Finders online, they all say the car needs an AGM type battery due to the regenerative braking. :confused:

I wonder what determines whether you get an AGM or EFB? Maybe the diesels get an AGM?

I bet Audi and VW owners get the AGM as standard ;)
 
Thanks. I'm not sure it explains though why in the owners manual it says the battery will either be AGM or EFB (note: it mentions AGM first) and the fact that if you type your registration into any of the Battery Finders online, they all say the car needs an AGM type battery due to the regenerative braking. :confused:

I wonder what determines whether you get an AGM or EFB? Maybe the diesels get an AGM?

I bet Audi and VW owners get the AGM as standard ;)

I have just checked my Tdi 184 FR and it has battery clearly marked AGM
other markings:-
VARTA 7PO 915 105
12V 68Ah

It would be normal for diesels to have higher Ah values due to higher compression but I cannot add any enlightenment on the AGM vs EFB debate.
 
I have just checked my Tdi 184 FR and it has battery clearly marked AGM
other markings:-
VARTA 7PO 915 105
12V 68Ah

It would be normal for diesels to have higher Ah values due to higher compression but I cannot add any enlightenment on the AGM vs EFB debate.

68Ah doesn't seem any higher to me - TSI owners appear to have 69/70Ah based on the replies so far.

But it's interesting that you've got the AGM in your diesel - all of the previous EFB replies have been from petrol owners.
 
I have just checked my Tdi 184 FR and it has battery clearly marked AGM
other markings:-
VARTA 7PO 915 105
12V 68Ah

It would be normal for diesels to have higher Ah values due to higher compression but I cannot add any enlightenment on the AGM vs EFB debate.

68Ah is the capacity (68 amps for an hour), for starting you are more interested in the CCA value (Cold Cranking Amperage).
 
The EFB battery looks to be 69AH/360A, and the AGM battery is 68AH/380A, if I am reading partsbase specs right. So yes the AGM battery has a higher CCA.
 
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