What size/type battery is right for my 2011 e92 335is?

Slim415 · 02-12-2022, 12:31 PM

If read conflicting things online. Some say H6 or H8. Should it be an AGM? This is the current battery I have but my stereo install guy said it looks a bit small for what my car should have.

ctuna · 02-12-2022, 12:45 PM

I agree it looks small they usually take up the entire space.
A 49/H8 would . Also missing is the foam on the end that is
bumper for the H8 Size.

Should say on the top of the battery what size it is.
If you put in a larger battery you will have to program for type and amp hours.
To find out what it is programmed for you will need some kind
of BMW diagnostic setup.

BMW standard tools and Ista D recommended.
Bimmergeeks Pro Tool if you want phone diagnositcs.

My last Interstate 49/H8 lasted 10 years and I could have gone farther.

Do you know if that is the original battery if not you will need the diags.
Depending on what you are putting in you may or may not need bigger but
these car are noted battery hogs on there own. Stereo board on e90post
says you can go up to 2000 watts of aftermarket stuff before there starts
to be problems.

Slim415 · 02-12-2022, 01:06 PM

Quote:

Originally Posted by ctuna

I agree it looks small they usually take up the entire space.
A 49/H8 would . Also missing is the foam on the end that is
bumper for the H8 Size.

The missing foam bumper, will that be a problem?

ctuna · 02-12-2022, 01:13 PM

There is the long metal screw with a kind of bracket .
Mine has a foam insert to .(see some of the ytube install video's)
Mine has a hard foam end piece never heard of a problem
never seen one without one but I don't look at this that often.
There are many threads here on battery replacement and programming.

Lots of ytube video's some show the foam piece.
look it up on RealOem.com

Maxmil982 · 02-12-2022, 01:21 PM

H8 95ah

marvinstockman · 02-12-2022, 03:24 PM

First, you live in CA, and you could probably get away with a motorcycle battery.

Are you having battery/electrical issues?

Remember, when the car is running, the alternator is what powers the car. The battery just starts the car, and in extreme cases might supplement the alternator.

Now if you're planning to run your new stereo for hours and hours while the car is off, you might need a much bigger battery or even a second battery.

Be happy and forget what the installer said.

Slim415 · 02-12-2022, 04:20 PM

Quote:

Originally Posted by marvinstockman

First, you live in CA, and you could probably get away with a motorcycle battery.

Are you having battery/electrical issues?

Remember, when the car is running, the alternator is what powers the car. The battery just starts the car, and in extreme cases might supplement the alternator.

Now if you're planning to run your new stereo for hours and hours while the car is off, you might need a much bigger battery or even a second battery.

Be happy and forget what the installer said.

Oh I'm definitely having battery problems. Just yesterday I charged it all day long on a portable wall charger. And then drove it for 25 minutes to the mall. 10 minutes later the batter was dead. Had my girlfriends dad jump it and drove home. And then the second I turned it off it was dead again. I know it sounds like the alternator might be bad but I'm pretty sure the battery is bad as well. Or maybe it's only the battery. I hope that's the case. But I want to replace the battery to eliminate it as an issue since it's pretty old.

Slim415 · 02-12-2022, 06:01 PM

I'm having a new battery put in right now. I'm confused because people have been saying to use an H8/49 battery but it doesn't fit. So I have to go with the H6/48. I don't know why it works for some people but it's too big for my car which is a 2011 335is.

ctuna · 02-12-2022, 06:54 PM

Maybe you are not having the right people put it in.
sounds like you trust to much to others.

BSM n54iS · 02-12-2022, 06:56 PM

H6/H8 both fit, that triangle tie down bracket at the very bottom has 3 different mounting holes iirc, at least 2.

Get a lightweight AG H6 40ah Li battery

marvinstockman · 02-13-2022, 09:48 AM

What is the alternator charging voltage with the car running?

Did this problem start with your new stereo?

What is the battery voltage after it sits overnight?

You need a cheap multimeter or:

https://www.amazon.com/s?k=cig+light...ref=nb_sb_noss

Slim415 · 02-13-2022, 11:19 AM

Quote:

Originally Posted by marvinstockman

What is the alternator charging voltage with the car running?

Did this problem start with your new stereo?

What is the battery voltage after it sits overnight?

You need a cheap multimeter or:

https://www.amazon.com/s?k=cig+light...ref=nb_sb_noss

Yep all problems started when I got a dash cam installed. And then they got a bit worse when I did the all digital gauge cluster retrofit. And then when I did my iDrive retrofit with a touchscreen system that's when it went downhill very fast. The AAA guy yesterday said my alternator was at 14 I think when the car is on. I don't know about the other things you asked though.

ctuna · 02-13-2022, 12:49 PM

Did you do an OEM idrive install .
If it's aftermarket I drive maybe it wasn't wired
in correctly .
Maybe the car is not going into sleep mode.
What do you have that is constantly on?

mainbearing · 02-13-2022, 05:00 PM

Maybe the dashcam was drawing power at all times, draining the battery.

In the picture you have one extra threaded hole for the battery bracket. Therefore if the old, short one was H6, then you should be able to fit an H7, which is about a 1.5" longer.

From the picture, H7 may be the largest you can fit in there, if the current one is H6.

I think the battery is mainly held by the bracket at the bottom. The foam might be a crash safety thing, because it pretty much drops right in, and that is not going to be holding anything as heavy as a battery.

H7 (Group 94R), the length is about 12-7/16". H8 (Group 49) is 13-15/16". Unless the shop only has a H6 (Group 48), which measures 11".

marvinstockman · 02-13-2022, 06:30 PM

With as much feeling as I can muster, you probably don't need a battery. You have another problem that is causing your problem, like the recently installed equipment.

That said, how many times has your battery gone dead, and how many times has it been recharged. Also, how old is it?

marvinstockman · 02-13-2022, 06:31 PM

Also, 14 volts is a good number for the alternator.

fazman · 02-15-2022, 08:44 AM

@Slim415 - where about are you located, I am near Laguna Seca Raceway? I have a coding cable and my laptop is setup with INPA.

Do you know how to access your Hidden Menu in the Kombi? that is going to be a great diagnostic tool to see how your battery voltage is holding up over nite.

Which new battery did you install?
* AGM/FLA?
* 60/70/80/90/110 AH?
* H6/H7/H8?

What did you do with the old battery? (keep it or gave it back as a core charge already)?

Did you update the VO?
Did you recode the car?
Did you register the new battery?

02-12-2022, 12:31 PM	#1
Slim415 Second Lieutenant 92 Rep 281 Posts Drives: 2011 335is 6MT Join Date: Jul 2019 Location: SF, CA iTrader: (0)	What size/type battery is right for my 2011 e92 335is? If read conflicting things online. Some say H6 or H8. Should it be an AGM? This is the current battery I have but my stereo install guy said it looks a bit small for what my car should have. Attached Images
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02-12-2022, 12:45 PM	#2
ctuna Lieutenant General 1921 Rep 13,122 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	I agree it looks small they usually take up the entire space. A 49/H8 would . Also missing is the foam on the end that is bumper for the H8 Size. Should say on the top of the battery what size it is. If you put in a larger battery you will have to program for type and amp hours. To find out what it is programmed for you will need some kind of BMW diagnostic setup. BMW standard tools and Ista D recommended. Bimmergeeks Pro Tool if you want phone diagnositcs. My last Interstate 49/H8 lasted 10 years and I could have gone farther. Do you know if that is the original battery if not you will need the diags. Depending on what you are putting in you may or may not need bigger but these car are noted battery hogs on there own. Stereo board on e90post says you can go up to 2000 watts of aftermarket stuff before there starts to be problems. Last edited by ctuna; 02-12-2022 at 01:08 PM..
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02-12-2022, 01:13 PM	#4
ctuna Lieutenant General 1921 Rep 13,122 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	There is the long metal screw with a kind of bracket . Mine has a foam insert to .(see some of the ytube install video's) Mine has a hard foam end piece never heard of a problem never seen one without one but I don't look at this that often. There are many threads here on battery replacement and programming. Lots of ytube video's some show the foam piece. look it up on RealOem.com Last edited by ctuna; 02-12-2022 at 01:20 PM..
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02-12-2022, 01:21 PM	#5
Maxmil982 Private 21 Rep 75 Posts Drives: 2010 e60 535i xDrive Join Date: Apr 2021 Location: Atlanta Georgia iTrader: (0)	H8 95ah
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02-12-2022, 03:24 PM	#6
marvinstockman Major 400 Rep 1,080 Posts Drives: 2011 BMW 328i Join Date: Aug 2015 Location: Rockville, MD iTrader: (0)	First, you live in CA, and you could probably get away with a motorcycle battery. Are you having battery/electrical issues? Remember, when the car is running, the alternator is what powers the car. The battery just starts the car, and in extreme cases might supplement the alternator. Now if you're planning to run your new stereo for hours and hours while the car is off, you might need a much bigger battery or even a second battery. Be happy and forget what the installer said.
	Appreciate 0 Quote

02-12-2022, 06:01 PM	#8
Slim415 Second Lieutenant 92 Rep 281 Posts Drives: 2011 335is 6MT Join Date: Jul 2019 Location: SF, CA iTrader: (0)	I'm having a new battery put in right now. I'm confused because people have been saying to use an H8/49 battery but it doesn't fit. So I have to go with the H6/48. I don't know why it works for some people but it's too big for my car which is a 2011 335is.
	Appreciate 0 Quote

02-12-2022, 06:54 PM	#9
ctuna Lieutenant General 1921 Rep 13,122 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	Maybe you are not having the right people put it in. sounds like you trust to much to others.
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02-12-2022, 06:56 PM	#10
BSM n54iS Brigadier General 2685 Rep 4,203 Posts Drives: '11 335is \| '16 Macan Turbo Join Date: Aug 2015 Location: Everywhere and Nowhere iTrader: (7)	H6/H8 both fit, that triangle tie down bracket at the very bottom has 3 different mounting holes iirc, at least 2. Get a lightweight AG H6 40ah Li battery __________________ '11 335is BSM MT "BMW Performance Editon" \| '16 Porsche Macan Turbo GruppeM CF Intake \| AR Resonated DP \| ER CP \| Turbosmart RacePort BOV \| Cobb FMIC \| RB Inlets \| RB External Mishi/Turner OCC \| Michelin PS4 \| BMW Performance Springs/Bilstein B8 + Dinan & M3 bits \| BMW Brembo BBK \| BMW Performance CF Spoiler \| BMW Performance CF Lip \| BMW Performance Alcantara \| PS Designs GTS Armrest \| AG H6-40 \| Rear Seat Delete
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02-13-2022, 09:48 AM	#11
marvinstockman Major 400 Rep 1,080 Posts Drives: 2011 BMW 328i Join Date: Aug 2015 Location: Rockville, MD iTrader: (0)	What is the alternator charging voltage with the car running? Did this problem start with your new stereo? What is the battery voltage after it sits overnight? You need a cheap multimeter or: https://www.amazon.com/s?k=cig+light...ref=nb_sb_noss
	Appreciate 0 Quote

02-13-2022, 12:49 PM	#13
ctuna Lieutenant General 1921 Rep 13,122 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	Did you do an OEM idrive install . If it's aftermarket I drive maybe it wasn't wired in correctly . Maybe the car is not going into sleep mode. What do you have that is constantly on?
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02-13-2022, 05:00 PM	#14
mainbearing Lieutenant Colonel 1085 Rep 1,682 Posts Drives: BMW 328i Join Date: Apr 2019 Location: LA iTrader: (0)	Maybe the dashcam was drawing power at all times, draining the battery. In the picture you have one extra threaded hole for the battery bracket. Therefore if the old, short one was H6, then you should be able to fit an H7, which is about a 1.5" longer. From the picture, H7 may be the largest you can fit in there, if the current one is H6. I think the battery is mainly held by the bracket at the bottom. The foam might be a crash safety thing, because it pretty much drops right in, and that is not going to be holding anything as heavy as a battery. H7 (Group 94R), the length is about 12-7/16". H8 (Group 49) is 13-15/16". Unless the shop only has a H6 (Group 48), which measures 11".
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02-13-2022, 06:30 PM	#15
marvinstockman Major 400 Rep 1,080 Posts Drives: 2011 BMW 328i Join Date: Aug 2015 Location: Rockville, MD iTrader: (0)	With as much feeling as I can muster, you probably don't need a battery. You have another problem that is causing your problem, like the recently installed equipment. That said, how many times has your battery gone dead, and how many times has it been recharged. Also, how old is it?
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02-13-2022, 06:31 PM	#16
marvinstockman Major 400 Rep 1,080 Posts Drives: 2011 BMW 328i Join Date: Aug 2015 Location: Rockville, MD iTrader: (0)	Also, 14 volts is a good number for the alternator.
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02-15-2022, 08:44 AM	#17
fazman Brigadier General 681 Rep 3,696 Posts Drives: 335 e90 Join Date: Feb 2011 Location: Los Angeles iTrader: (0)	@Slim415 - where about are you located, I am near Laguna Seca Raceway? I have a coding cable and my laptop is setup with INPA. Do you know how to access your Hidden Menu in the Kombi? that is going to be a great diagnostic tool to see how your battery voltage is holding up over nite. Which new battery did you install? * AGM/FLA? * 60/70/80/90/110 AH? * H6/H7/H8? What did you do with the old battery? (keep it or gave it back as a core charge already)? Did you update the VO? Did you recode the car? Did you register the new battery? Last edited by fazman; 02-15-2022 at 08:53 AM..
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