H8 size battery install in a 2015 Passat

Jetta_Pilot

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Duralast Platinum H8-AGM battery, or any other larger than OEM size battery.

Auto zone lists this battery as a fit for a 2015 Passat. It does fit after quite a bit of work to make it fit since the H8-AGM is just under 10cm (4") longer, the width is the same. I did not try to fit the silly battery cover back on the new battery, it's too short anyway. This battery weighs 65 lbs.

In order to fit the battery the complete air filter box needs to be removed. The battery tray also needs to be removed and a high lip at the firewall end needs to be sawn off. Also some other high points sticking up on the battery tray need to be sawn off. There is also a mount for the air filter box which needs to have a rib removed to allow the battery to sit flat on the tray. Lastly on the the battery hold down bracket the two short tabs need a bit of bending to make it fit. I used two vise grips to do that.

Next is to re-install the battery tray. Now it's time to position the new battery, I used a medium screwdriver between the lip on the tray to force the battery into place and then lock it down with the clamp. Then with a with a lot of forcing get the air filter box back into place and the new battery can be connected with the original cables, they just fit. Positive first, negative last.

Tools required, a # 20 torx driver. A 10mm and a 13mm socket and a 6mm Allen wrench. I also used the medium blade screwdriver to spread the battery clamps.

Total time for me was just under three hours. But I'm not a spring chicken anymore and it was hotter than h*ll. Sorry no pictures, I was too busy.
 

Jetta_Pilot

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odd why it would take so much effort seeing the 12-14 Passats had H8 size standard.
Another good write up (from euroland) for a mk7 which seems a bit easier.
https://www.golfmk7.com/forums/showthread.php?t=7926
The link you provided only mentions batteries of 27.5 cm long which my OEM is/was as well. The H8 battery is 34 cm in length, so they are two different batteries. The OEM is the same size as a H6 and that would have been a 20 minute job to just exchange same size batteries.
 

LeeM

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There are different size battery trays available but the actual battery size designation is open to interpretation. The Interstate H8 is listed as a 95 Amp Hr battery:

3C0-804-869-E Battery Tray for 72 AMP HOUR BATTERY

3C0-804-869-D Battery Tray for 95 AMP HOUR BATTERY

1K0-915-333-H Battery Tray for 61 AMP HOUR BATTERY
 

Jetta_Pilot

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There are different size battery trays available but the actual battery size designation is open to interpretation. The Interstate H8 is listed as a 95 Amp Hr battery:
3C0-804-869-E Battery Tray for 72 AMP HOUR BATTERY
3C0-804-869-D Battery Tray for 95 AMP HOUR BATTERY
1K0-915-333-H Battery Tray for 61 AMP HOUR BATTERY
When you are 1 hour away from the nearest VW dealer and 1,000 miles south of the US border you do not have a choice, you adapt!
 

740GLE

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The link you provided only mentions batteries of 27.5 cm long which my OEM is/was as well. The H8 battery is 34 cm in length, so they are two different batteries. The OEM is the same size as a H6 and that would have been a 20 minute job to just exchange same size batteries.
Wow so you can slide an even bigger battery than the upgraded battery for the mk7, didn't know that.

Hopefully you're able to get 5+ years out of it and the heat doesn't do it in.
 

Jetta_Pilot

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Wow so you can slide an even bigger battery than the upgraded battery for the mk7, didn't know that.

After the first time trying to seat the battery in and seeing it sat at an angle which did not allow for the bracket to hold it down. Then I had to figure out the reason what did that. It really didn't slide in, a lot of pushing and perseverance eventually did it. Plus a lot of words I cannot repeat here.

As an aside I'm sure that this is not a VW approved method!:rolleyes:
 

Jetta_Pilot

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Follow up

I had already described my 3 hour installation of a H8 battery in a H6 spot.

Anyway the car sat since January 7th until today March 9th where I had to use it. After my starting problems in December I was wondering about starting the car.

Started immediately without any hesitation. Very pleased with my Autozone H8 AGM battery.
 

93celicaconv

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There are different size battery trays available but the actual battery size designation is open to interpretation. The Interstate H8 is listed as a 95 Amp Hr battery:

3C0-804-869-E Battery Tray for 72 AMP HOUR BATTERY

3C0-804-869-D Battery Tray for 95 AMP HOUR BATTERY

1K0-915-333-H Battery Tray for 61 AMP HOUR BATTERY

So you are saying, for a 2015 Passat TDI that came with an OEM 72 Amp-Hr Battery (which I believe to be an H6 case size), one can order replacement battery tray for a 95 Amp-Hr battery (which I believe is an H8 case size), and the 3" longer H8 battery will fit in the available space on this model?

I'm needing to plan for a replacement battery soon myself, as mine is 4+ years old now and is starting to show signs of giving up. I like the idea of an H8 case size battery. Without consideration of the battery tray, I don't see the cavity space available in a 2015 Passat TDI as having sufficient room for a battery 3" longer than the H6 battery that is in there now.

Has anyone "easily" installed an H8 case battery in a 2015 Passat TDI that can provide guidance if "easily" possible?
 

93celicaconv

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The 95AH battery says it is 353mm (13.8976") long x 175mm (6.8897") wide x 190mm (7.480") high, which makes it dimensionally identical to an H8 (Group 49) battery, which is exactly 2-15/16" longer than my current H6 (Group 48) battery in my 2015 Passat TDI SEL Premium. There is no way I can get a 3" longer battery in the physical space length-wise for an H8 (Group 49) battery, without doing some major cutting of current stuff.


Has anyone done an H8 (Group 49) battery replacement in a 2015 Passat TDI in which the physical install was a simple drop in?
 

BKmetz

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odd why it would take so much effort seeing the 12-14 Passats had H8 size standard.
I believe the H8 was standard only in the VR6 Passats and mounted in the trunk on the left side. I found a photo.


The rest of us got the H6 size mounted under the hood.

I'm going to replace my battery soon. I'm thinking of going with an AGM in H6 size. I've read that the BCU, Body Control Unit, battery settings need to be changed for charging an AGM battery with VCDS. I don't have VCDS but I know people who do. Could someone take a screen shot so I can show them the menu to do this?

Thanks.

:)
 
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93celicaconv

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Wjat BKMetz says! For generic listings, it does say H8 for Passats, but I've also found some more specific information where the H8 only pertained to certain model Passats, such as the VR6 (and the CC). So unless someone else had an easy time installing an H8 battery in a 2015 Passat TDI, I'll assume it is not possible without some permanent modifications.

I also am thinking going with an H6 AGM replacement, so I would be interested in seeing how VCDS is used for changing the BCU parameters on a 2015 Passat TDI. I get the serial number change (simply increase the serial number by "1" so the BCU knows there is a new battery installed), but I don't know where the setup is to go from conventional flooded lead-acid to AGM batteries.
 

740GLE

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i swore our '12 battery was larger than our '15 maybe i'm wrong with the designation.

I believe it's just a drop down to change the type of battery. Golf daves DIY should have a nice walk through for switching types.
 

BKmetz

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I'm going to the dealer today for the airbag recall. I'll ask if they do anything with the BCU when installing an AGM battery. I expect to get a 'huh?' look. ;)

:)
 

BKmetz

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I'm going to the dealer today for the airbag recall. I'll ask if they do anything with the BCU when installing an AGM battery. I expect to get a 'huh?' look. ;)

:)
And this went exactly as I thought it would.

I asked the guy at the service desk, when they install AGM batteries, do they make any changes to the BCU to accomodate the different rates in charging. No VW models sold in the US come with AGM batteries so they never install them, only VW lead acid batteries as replacements. So that answers that.

:)
 

93celicaconv

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I guess if VW dealers don't have Passat H6 AGM batteries to sell, they wouldn't have the procedure available for how to sell AGM batteries.

The original VW H6 battery in my 2015 Passat has a reserve capacity of 72 amp-hrs. I haven't yet found an AGM H6 battery with more than 70 amp-hrs reserve capacity. I know on TDI's, reserve capacity is highly important. So I was hoping the replacement battery I get would have a higher value. I know the 2 amp-hr lower AGM H6 isn't that much lower, but I was looking for 80 amp-hr or higher. Just can't find that in an H6 AGM. Is there such an H6 AGM battery having a higher reserve capacity than 72 amp-hrs?
 

BKmetz

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In doing some research this morning I found a good link on replacing batteries over at Vortex. It includes links to Ross-tech for VCDS battery adaptations, if needed.

Some questions:

Do our cars have battery control modules?

Do our cars need to have new batteries registered with VCDS? This would include changing to an AGM battery.

Vortex link. https://forums.vwvortex.com/showthread.php?9254293-VDCS-Changes-for-Battery-Replacement

Ross-Tech link 1. https://www.youtube.com/watch?v=IJAScg6JrYI&feature=youtu.be

Ross-tech link 2. http://wiki.ross-tech.com/wiki/index.php/Battery_Replacement

Golf MK7 forum link. https://www.golfmk7.com/forums/inde...bigger-capacity-battery-to-a-mk7-golf.320084/

And then there is this thread that says just drop in your new battery, no battery coding or registration with VCDS, ignore the warning lights as they will clear themselves, and drive on. http://www.forums.tdiclub.com/showthread.php?t=428335

We need an expert to chime in here. oilhammer? Calling oilhammer? (Turns on the batman style search light, only with a VW logo) ;)
 
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Jetta_Pilot

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I'm going to the dealer today for the airbag recall. I'll ask if they do anything with the BCU when installing an AGM battery. I expect to get a 'huh?' look. ;):)
You'll need a VCDS to set the charging system from flooded battery to AGM battery.
The AGM prefers a lower charge rate compared to a flooded battery!
 

oilhammer

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There are just too many to list....
I do it the correct way. You can shorten the life of the alternator, battery, or both, by not telling the control module that a "new" battery has been installed.

BMW has a TSB about this, because hacks end up burning up the wiring harnesses if this is not done properly! :eek:

It isn't like it is hard to do. And it is only on models that have the "smart charging" in conjunction with the battery control module. This is also much more prevalent on so many of these newer cars cursed with start/stop, because the controller NEEDS to be able to better manage the battery so it does not suddenly go dead at a stop light. This is also why the warning lights should not be ignored. They are there for a reason.

I personally see no reason why an AGM battery is any "upgrade" to a car that is not specifically designed to use one, because the charging system certainly won't do it any favors. AGM seems to be limited to very high end high electrical consumer vehicles and lots of the start/stop stuff. I suppose they are a little more robust for bouncing around and such, but conventional lead acid batteries are pretty good in that regard too.
 
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93celicaconv

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BKMetz, most of the links you provided involve vehicles with a BCM (battery control module) or BEM (battery energy monitoring) systems. Does a 2015 VW Passat TDI have a BCM? My old OEM battery does not have a label with a BEM code on it, so it is not BEM. But I think it has a BCM. Are the steps clearly stated in how to use VCDS to make the changes necessary to go from a flooded to an AGM battery? And what values are needed?
 

BKmetz

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BKMetz, most of the links you provided involve vehicles with a BCM (battery control module) or BEM (battery energy monitoring) systems. Does a 2015 VW Passat TDI have a BCM? My old OEM battery does not have a label with a BEM code on it, so it is not BEM. But I think it has a BCM. Are the steps clearly stated in how to use VCDS to make the changes necessary to go from a flooded to an AGM battery? And what values are needed?
Everything you are asking is what I'm trying to find out. So far no definitive answer. Oilhammer states he does use VCDS to tell the system it has a new battery.

:)
 

oilhammer

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There are just too many to list....
...on cars that have the module. The Gateway installation list will have this information, but the NMS doesn't. And to follow up with the [clueless] dealer comment: the Volkswagen Phaeton has one, so they DID sell a car that requires this be input. :p
 

93celicaconv

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...on cars that have the module. The Gateway installation list will have this information, but the NMS doesn't. And to follow up with the [clueless] dealer comment: the Volkswagen Phaeton has one, so they DID sell a car that requires this be input. :p
Oilhammer, thanks for your guidance. For whatever reason, I'm still not clear what I need to do (if anything) to replace my OEM flooded led acid H6 battery with an AGM H6 battery on my 2015 Passat TDI SEL Preimium NMS vehicle. Do I need VCDS to re-code anything, or not? If re-coding is required, what/where are the instructions foe doing that properly and clearly?
 

oilhammer

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There are just too many to list....
You should just save your money and put the same battery in it as it left the factory with. I would get it from Volkswagen, too, as the batteries they sell are actually pretty good and they are price competitive. We have been putting genuine Volkswagen batteries in VAG products for years now, ever since the QC tanked on Interstate. We also carry AC Delco, but those are awful.

All of my dubs have Volkswagen (usually Enertec or Varta) batteries in them.

Keep in mind ALL the CR TDIs (the 4 cyl at least) are HARD on their batteries. High underhood temps during regen, as well as long aggressive after run times for cooling fans and electric water pumps all make for shorter battery life in general. And since the alternator isn't primed for AGM battery charging, it really is not going to give you any advantage in that car. It *might* last a wee bit longer, but it will likely not be worth the extra expense.
 

93celicaconv

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You should just save your money and put the same battery in it as it left the factory with. I would get it from Volkswagen, too, as the batteries they sell are actually pretty good and they are price competitive. We have been putting genuine Volkswagen batteries in VAG products for years now, ever since the QC tanked on Interstate. We also carry AC Delco, but those are awful.

All of my dubs have Volkswagen (usually Enertec or Varta) batteries in them.

Keep in mind ALL the CR TDIs (the 4 cyl at least) are HARD on their batteries. High underhood temps during regen, as well as long aggressive after run times for cooling fans and electric water pumps all make for shorter battery life in general. And since the alternator isn't primed for AGM battery charging, it really is not going to give you any advantage in that car. It *might* last a wee bit longer, but it will likely not be worth the extra expense.
I saw the VW replacement batteries were priced well. And your perspective is just what I was looking for. Does VW charge labor cost on top of battery cost if they install it? If so, and I have VCDS, can I simply install it to save on the labor cost? If yes, what do I need to do regarding coding to replace my OEM battery with one from a VW dealer?
 

BKmetz

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OK, the NMS Passat does not have a battery control module and there is no need for VCDS.

So when I replace my Passat battery, I'm going to plug in my memory saver through the OBD-II port and simply swap out the battery.

My only decision at this point is what brand do I want to buy. I would buy the VW Enertec battery again if I caught a sale. Sometimes the dealer will have a special on oil, filters, tires, batteries, etc.

I googled Enertec and it's not owned by Johnson Controls, a big plus for Enertec. Johnson Controls bought Varta years ago so that probably why VW stopped using them.

Drive more and worry less.

:)
 

93celicaconv

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BKmetz, can you tell me what make/model/part number "memory saver" you have? I'm not aware of such a thing, but I can see where having one is very advantageous when needing to disconnect a battery on today's cars.
 

oilhammer

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There are just too many to list....
I saw the VW replacement batteries were priced well. And your perspective is just what I was looking for. Does VW charge labor cost on top of battery cost if they install it? If so, and I have VCDS, can I simply install it to save on the labor cost? If yes, what do I need to do regarding coding to replace my OEM battery with one from a VW dealer?

I don't work for free, I assume you don't, so I would not expect the dealer to either. ;) So yes, they would charge something to install a new battery. I would guess maybe a half hour labor (likely the "minimum") and would/should include any memory saving and/or recoding of anything, which as I stated already your car does not require anything with regards to the battery however in some cars the radio coding can change. I use some method to retain the battery memory (also stated previously) to avoid this. So I do not even have to mess with resetting the clock or pinch protection, etc.

I would say replacing the battery isn't hard, but if I had a dime for every improperly installed/wrong battery I have come across, I would be a rich man. Just make sure the lip on the outside edge of the battery is UNDER the retaining lip on the tray, and that the hold down is oriented properly and the bolt put in at the right angle and not cross threaded, and that any covers are put back in place as intended.
 

BKmetz

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BKmetz, can you tell me what make/model/part number "memory saver" you have? I'm not aware of such a thing, but I can see where having one is very advantageous when needing to disconnect a battery on today's cars.
It's just an external 12V power source that you plug into the power outlet/cigarette lighter or OBD-II port so one doesn't loose all the memory settings cars have today. I'm using an OBD-II port cable as I use mine on all different makes of cars because on some cars the 12V power socket/lighter socket is switched. The OBD-II port is unswitched and feeds right off the battery.

You can simply connect a battery charger alligator clips to your battery cables when you disconnect your battery. I prefer using something that plugs into the OBD-II port as I always manage to bump the cables when working under the hood and loose power anyway.

Here is a link I started about saving the settings when disconnecting the battery. I'll post photos in that thread later today and show how I set my system up.

http://forums.tdiclub.com/showthread.php?t=503322

:)
 
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