AGM Battery

Jul 30, 2025
6
1
Looking to replace the EFB battery with an AGM,Tanya site lists a Bosch S5 A08 but I wanted to use the existing OEM fabric cover,and the above one is 278mm as opposed to 242mm on the EFB one.
Saw this one which looks identical to the S5 A08 but the correct size 242mm
It says this doesn’t fit but can’t see why,as its size is identical to the EFB one and the posts are same sides,at a loss as to why it doesn’t fit.
Anyone have an answer?
 

Karollo

Active Member
Jul 13, 2025
19
13
Poland
It may show that it doesn't fit because of the dimensions, but rather because of the battery type (EFB vs AGM). It's possible that the search engine is rigidly stuck on the original battery type.
 

RUM4MO

Active Member
Jun 4, 2008
8,121
1,128
South Scotland
It sounds like your Leon is a lower powered and so maybe lower speced car, so at the factory it was fitted with the smaller battery - which is exactly wht is fitted to my wife's 2015 VW Polo 1.2TSI 110 SEL.

I sort of planned to change its EFB to an AGM and "move up one size" - and for that car, that involves buying a new battery tray and the insulating blanket, I've done all of that but the original battery still refuses to die enough to encourage me to implement all these changes, probably it lives on as I've taken care of it and how we use that car!

So, what you can do is, either buy this "one size up" and get it coded to the car along with buying a new insulating blanket, which from memory costs a bit more than you might expect, or stick with the same amp hour and CCA of your original EFB one that is currently fitted, and get that coded to your car.

If in doubt about Bosch batteries, just go onto their website and get the Bosch code of the one that you want, and order that in from Tayna batteries.

Really it is only the capacity in amp hours and the cold cranking amps, ie CCA that you are aiming to match - along with the profile/shape and terminal layout - just check that the terminal layout is the same as the one you have in the car at the moment , to make sure that + - or not swopped over. Just be aware that as time moves on, capacity and CCA might creep up a bit so they could be slightly higher than the old EFB in your car, so don't worry about that.

Edit:- I'm guessing that the battery tray in your Leon can accomodate the bigger size, as that is what gets fitted to bigger engined and higher trim level cars, the one other slight worry about fitted a slightly bigger/longer battery is, "will the leads still fit okay?" as they do tend to be designed to just fit.

My "plan B" is to sell this bigger Bosch AGM to my daughter for use in her Leon Cupra, but as her battery is dying but not yet caused a problem, that will be very tricky to do! (younger people normally only spend money after the event)
 
Last edited:

RUM4MO

Active Member
Jun 4, 2008
8,121
1,128
South Scotland
In fact, now that I've checked both Bosch batteries, the S5 A05 should fit perfectly to replace your original same profile/size or frame size EFB which will be a 320A (DIN)/640A (EN) 59AmpHour size - or near enough that spec depending on the age of it and your car.
 
Jul 30, 2025
6
1
It may show that it doesn't fit because of the dimensions, but rather because of the battery type (EFB vs AGM). It's possible that the search engine is rigidly stuck on the original battery type.
Thanks for the reply.
I don’t think that’s the reason,car is Leon 2017 1.4 TSI,and battery tray has three different sizes it can adjust to,As said I didn’t want the bigger 278mm S5 A08 as it would mean getting a bigger cover.
 
Jul 30, 2025
6
1
In fact, now that I've checked both Bosch batteries, the S5 A05 should fit perfectly to replace your original same profile/size or frame size EFB which will be a 320A (DIN)/640A (EN) 59AmpHour size - or near enough that spec depending on the age of it and your car.
Cheers for the reply,I can’t see why it wouldn’t fit either,but no battery site says it would fit.
Strange.
 

RUM4MO

Active Member
Jun 4, 2008
8,121
1,128
South Scotland
The bottom line is, if this is the direct AGM equivalent of an EFB and your car has that frame size, capacity, CCA (EN) and terminal configuration - which the AGM you have picked, has, then that is the correct battery for what you want to achieve.
The major down side is that it will cost less, but I'm sure that you can handle that even if the battery sellers would rather not.
 
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RUM4MO

Active Member
Jun 4, 2008
8,121
1,128
South Scotland
One other comment/observation:- on that website, when you go to the "batteries" listing and not "batteries sorted by reg number", the battery you get offered is high up the "best sellers" on page 1, the battery you want to buy is on page 2!
 
Jul 30, 2025
6
1
One other comment/observation:- on that website, when you go to the "batteries" listing and not "batteries sorted by reg number", the battery you get offered is high up the "best sellers" on page 1, the battery you want to buy is on page 2!
Cheers,appreciate the feedback
 

nd-photo.nl

Active Member
Mar 6, 2012
4,470
531
The Netherlands
youtube.com
The bottom line is, if this is the direct AGM equivalent of an EFB and your car has that frame size, capacity, CCA (EN) and terminal configuration - which the AGM you have picked, has, then that is the correct battery for what you want to achieve.
The major down side is that it will cost less, but I'm sure that you can handle that even if the battery sellers would rather not.
Exactly this. I also replaced my battery after I bought my Cupra. I went from a Banner EFB battery to a Exide AGM battery. Same dimensions, but higher capacity

AP1GczN3gizUFpkLnlOyt_eSHildzf3l__m2rMVm_DYbxUBBXioQ2sgjRL0vh130K3s6kJGXrUE2ZoJd2EieN77kiev3fQ3cYX8Wd9__U2wv8B0pAJ41MgC9fHxytltWFmWP0docAGXsi6FiU5EEr51aubLvWA=w1560-h878-s-no-gm


Just like a DOT code on a tire, a battery also has a date code (week 22 2015, so 10years old)

AP1GczPcE5syxxtOU5fSTyafUjDOrq2d0gaJmKNNP4BV0QPGZjwMN9F2ZCKJk6Defl-3wcyZIr6YXF3vFlERDWZuuZsqoPWDuI00ZFRQSYp4tG-J_XvJWBWqQC7MwF2MhHE0Um2_XaEtWP_ycvNQIXLbcXIObA=w1560-h878-s-no-gm


Exide EK720

AP1GczP6APKMFi1aUefRINntOyEYin5mV1_l7g6XqztyykGT1lZ5oubIR9R_kKPvT8xiaAdLxPtWwuAV7wYaHIpZRlmvhA-uMlxE6rLKxfUbGjxSkfkfUjDN9AYTrxjfpLbd18pDtZh2PbTEFU6cUgzC1zzE4g=w1560-h878-s-no-gm


AP1GczPzuXQzOc60wMsY7C6NOn2cEm0qGa88ijCnccGBtld6NpZjgpqUMy6oodL4Dp9ARoaYvLzgsNmIUwoyQUctITgbYb-WxcGBrBtMlzNEla-vntvZRWY_Dih9B31CHOKOM9GIBZELpBLrx7fr_1TAt57TeA=w1560-h878-s-no-gm


Don't forget to change the values in VCDS (or other device) where needed

AP1GczMXc08JY8S5DoCWogzDYcOEqXj1WK_Gvyu7bvzViuiJ25lMCFl-8uhg_DZN-J5Vi271ISLjt-9K1aQ8X_1VOg6xPXE0gMzxpx5EB4MsLPvYs9HYhsQIvzBBnqiCPyTjkdpa1CRAXXRNPjPzj6kW-1GjXg=w1560-h878-s-no-gm


AP1GczNC5s_JPdWUlO0n8f3MQfPhMisaHM6afhQ1I-0AIwAZgETNh8zY1jMrN6AHLQEP-9QO0oSzMEnLDRAXXpOc4VcCCZ0jYBWN9EyHtI7bR_NJjP8j9VSa1s0S2XjLCEfz_3lhY9EgUgV_zR0s32tLr7GtYQ=w1560-h878-s-no-gm
 
Jul 30, 2025
6
1
Exactly this. I also replaced my battery after I bought my Cupra. I went from a Banner EFB battery to a Exide AGM battery. Same dimensions, but higher capacity

AP1GczN3gizUFpkLnlOyt_eSHildzf3l__m2rMVm_DYbxUBBXioQ2sgjRL0vh130K3s6kJGXrUE2ZoJd2EieN77kiev3fQ3cYX8Wd9__U2wv8B0pAJ41MgC9fHxytltWFmWP0docAGXsi6FiU5EEr51aubLvWA=w1560-h878-s-no-gm


Just like a DOT code on a tire, a battery also has a date code (week 22 2015, so 10years old)

AP1GczPcE5syxxtOU5fSTyafUjDOrq2d0gaJmKNNP4BV0QPGZjwMN9F2ZCKJk6Defl-3wcyZIr6YXF3vFlERDWZuuZsqoPWDuI00ZFRQSYp4tG-J_XvJWBWqQC7MwF2MhHE0Um2_XaEtWP_ycvNQIXLbcXIObA=w1560-h878-s-no-gm


Exide EK720

AP1GczP6APKMFi1aUefRINntOyEYin5mV1_l7g6XqztyykGT1lZ5oubIR9R_kKPvT8xiaAdLxPtWwuAV7wYaHIpZRlmvhA-uMlxE6rLKxfUbGjxSkfkfUjDN9AYTrxjfpLbd18pDtZh2PbTEFU6cUgzC1zzE4g=w1560-h878-s-no-gm


AP1GczPzuXQzOc60wMsY7C6NOn2cEm0qGa88ijCnccGBtld6NpZjgpqUMy6oodL4Dp9ARoaYvLzgsNmIUwoyQUctITgbYb-WxcGBrBtMlzNEla-vntvZRWY_Dih9B31CHOKOM9GIBZELpBLrx7fr_1TAt57TeA=w1560-h878-s-no-gm


Don't forget to change the values in VCDS (or other device) where needed

AP1GczMXc08JY8S5DoCWogzDYcOEqXj1WK_Gvyu7bvzViuiJ25lMCFl-8uhg_DZN-J5Vi271ISLjt-9K1aQ8X_1VOg6xPXE0gMzxpx5EB4MsLPvYs9HYhsQIvzBBnqiCPyTjkdpa1CRAXXRNPjPzj6kW-1GjXg=w1560-h878-s-no-gm


AP1GczNC5s_JPdWUlO0n8f3MQfPhMisaHM6afhQ1I-0AIwAZgETNh8zY1jMrN6AHLQEP-9QO0oSzMEnLDRAXXpOc4VcCCZ0jYBWN9EyHtI7bR_NJjP8j9VSa1s0S2XjLCEfz_3lhY9EgUgV_zR0s32tLr7GtYQ=w1560-h878-s-no-gm
Cheers,I’ve got a mechanic mate who can do it
 
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