The battery in my Fiesta states that it is a SLI, as recommended by Ford. Varta, who supply ford, say it should be an EFB type D54.

Who is correct?

7 hours ago, Jeff Silver said:

The battery in my Fiesta states that it is a SLI

When did it tell you that ? 🤣

Welcome to the Forum.

Your car has stop/start so therefore will need an EFB (or AGM) battery. Looking at Tayna (which I've used a few times), you will need the D54 battery. The SLI is an ordinary standard battery type which won't cope with stop/starts. 

https://www.tayna.co.uk/car-batteries/varta/d54/

Before you order, please check the sizes of your existing battery with a tape to make sure they match. There was a thread a few years ago saying there was 2 sizes/codes it could be. 

7 hours ago, Jim H said:

Welcome to the Forum.

Your car has stop/start so therefore will need an EFB (or AGM) battery. Looking at Tayna (which I've used a few times), you will need the D54 battery. The SLI is an ordinary standard battery type which won't cope with stop/starts. 

That would be true except this car is an MHEV.  The 48v battery is used for stop start on those.  Technically they don't need an EFB.

This poster has asked the same question before.  I believe they are hoping to find someone with exactly the same model to compare with.

Well my Puma is pretty close to a Fiesta (just jumped up a bit). It is a 155 mHEV and it was supplied from new with an EFB battery.

26 minutes ago, pcaouolte said:

Well my Puma is pretty close to a Fiesta (just jumped up a bit). It is a 155 mHEV and it was supplied from new with an EFB battery.

The Puma is builtin a completely different country to the Fiesta.  You probably got a 'Rombat' branded battery on that?

1 hour ago, TomsFocus said:

You probably got a 'Rombat' branded battery on that

Yes I did and it is still going strong despite all the negative comments about them.

If the Puma 1.0 mHEV 155 engine gets an EFB battery, why would the Fiesta 1.0 mHEV 155 engine get anything different?

1 hour ago, TomsFocus said:

You probably got a 'Rombat' branded battery on that?

As usual, can't find the evidence but I have an idea Ford switched from the Rombat to Varta (as on most other models) at some point. 

Certainly people on the Puma forum (very lengthy thread https://pumaforums.co.uk/viewtopic.php?t=885) who have succeeded in getting a replacement from Ford seem to have got a Varta EFB.

25 minutes ago, pcaouolte said:

If the Puma 1.0 mHEV 155 engine gets an EFB battery, why would the Fiesta 1.0 mHEV 155 engine get anything different?

Yes, I'm sure we've discussed that on another thread (which again I can't find when I want it!😀) and concluded that economies of scale meant EFB on everything, MHEV or not.

It would be interesting to see a pic of the OPs battery to see if it had a Ford logo and was OEM or a replacement. I think we have seen posts of OEM batteries in MHEV Fiestas and they were as below, the same as I've had in my non-MHEV cars.

Edit: just did a quick Google and came across the second image below, from an ended EBay sale, marked as Fiesta/Focus/Puma battery

 

Should it say on the battery label if it is a EBB or AGM type? My non-hybrid does. It might be helpful if the OP, Jeff, posts a pic of his existing battery.

Looking at the bottom pic in this thread, it could be a Varta SLI, which is an ordinary battery. I downloaded it and rotated it. As said, we need a pic of your battery to confirm.

 

21 minutes ago, Jim H said:

it could be a Varta SLI, which is an ordinary battery. I downloaded it and rotated it. 

Yes, SLi to my eyes also.

Given the number of 12v battery issues we see on here, though, I'd be inclined to go with the EFB.

 

1 hour ago, pcaouolte said:

Yes I did and it is still going strong despite all the negative comments about them.

If the Puma 1.0 mHEV 155 engine gets an EFB battery, why would the Fiesta 1.0 mHEV 155 engine get anything different?

Consumables like batteries, brake pads and tyres are often cheaper to source locally, so I wouldn't rely on the Puma having the same brands as the Fiesta from the factory.

The main point of this thread is to determine whether a large batch of Fiestas got an SLI battery between certain build dates or whether this car just has the wrong battery fitted for some reason.

I do t know the answer unfortunately.  But I agree with Roger, if replacing I would just use an EFB anyway.  Price difference isn't much nowadays.

51 minutes ago, Eric Bloodaxe said:

Yes, SLi to my eyes also.

Given the number of 12v battery issues we see on here, though, I'd be inclined to go with the EFB.

 

I was about to agree with you, but looked on Tayna at the specs of both. Comparing 100 sized Varta Silver (4 year warranty), the standard actually has a higher capacity and slightly higher CCA, plus of course it's cheaper.

EFB: https://www.tayna.co.uk/car-batteries/varta/d54/

SLI (standard): https://www.tayna.co.uk/car-batteries/varta/e43/

Size isn't everything! 😉

The EFB battery should cope better with high discharge and frequent recharge cycles.  In the past we'd associate that with stop start.  But it may also be better for frequent short journeys with the way the modern charging profiles are designed.

It would be interesting to compare both of those batteries in the real world to see which one actually works better on an MHEV.  I wouldn't like to call it on paper figures alone.