E70 Battery Replacement - DIY

[bmrboi2]

Originally Posted by ard

If you buy Carly, they will extort another 9.95 for the battery coding, as I recall

Yup. I did it. I've used it to register a new battery for a few of my friends.

[giaka]

Originally Posted by DWill

You used Carly to register/code your new battery ?
I looked into buying Carly, I didn't see battery registration/coding in the list of features. I sent them a email asking if battery registration/coding could be done with Carly and they replied saying it was not supported.

Because of that reply I didn't buy it.

Maybe I got bad information ?

I just purchased a Carly about 3 weeks ago, I also purchased the new "subscription based" Full Porgram. Yeah thats right, Carly only works for a year now and you get to buy it again. Anyway, yes you can register a battery with it (I had to do ours).

[noelskii]

Just looked at my battery and it is a CarQuest 94R70

PART NO: 94R70
CCA @ 0*F: 765
20 AH RATE: 80

Does this battery suck or what? Looking to replace it sometime this week...

My two choices are:

Bosch Part#: 49-850BAGM

AutoCraft Part No: H8-AGM

Both are around the same price... Any suggestions?

Thanks!

[Kostyan]

I found a great deal on a couple of batteries in H9 size, however, both exceed my stock battery 105 AH rating - they are both at 110 AH.

The subject has been casually covered in this and other threads, but wanted to revisit all pros and cons of getting a batter with a bit higher AH rating.

[josiahg52]

I was in the opposite situation. The AGM H8 battery I found was listed at C/20 95Ah. The AGM battery options cover 90 and 105Ah. I consulted with the battery manufacturer and they recommended I choose the 105Ah option, assuming of course that the BMW capacities are indeed C/20 capacities. Given the options and the relative standard use of such capacities throughout the industry, this seems very likely.

Not knowing exactly how the BMW IBS works and the exact strategies used, mathematically, at worst, using a battery with a higher capacity than the system expects means your battery will be chronically undercharged and that would certainly lead to a shorter life span. Likewise, a battery that is of a lower capacity than the system is set up for - as in my case - may experience a shorter lifespan but for the opposite reason. Ultimately, the actual effects will depend on the battery design and construction.

ETA: I find it interesting that the OP replaced his battery with a Interstate MTP-49/H8 100Ah battery and stated that it was the same type that the dealer had installed in the past. 100Ah is not an option so I wonder what the dealer did? Probably nothing special or extra and just picked the closest value.

ETA2: I looked in Carly and the battery capacity options are the same as those in the first couple of posts of the thread. Another interesting facet is a note in the battery registration window in Carly that says to choose the next lowest capacity if your exact battery capacity is not shown. I'm not sure of the source for that guidance. The Ah value is probably used to help determine state of charge (SOC) more than define precise charging profiles. I'd hope that an INTELLIGENT Battery Sensor would use voltage, temperature and current indications to determine when the battery needed charging and when to terminate that charge. For that reason, I'm probably going to choose the 90Ah option for use with my 95Ah rated battery.

[Qsilver7]

Originally Posted by PAX5

I recently bought an Autozone Duralast H8-AGM battery to replace my original equipment AGM battery.

In the end I decided against the swap because no one at Autozone or the manufacturer of the battery (East Penn Manufacturing) was able to tell me the Amp Hour (AH) rating of the H8-AGM battery (see pics below)...

The AH number is what determines whether or not any coding needs to be performed. The problem with using one of the many formulas available for converting the Reserve Capacity Rating to Amp Hour rating results in values much higher than the 80ah-agm and 90ah-agm settings in Tool32 in EDIABAS. From what I know about AGM batteries, you don't want to over-charge or under-charge the battery ...

Just an FYI (sorry if this mystery was solved further in the thread...I haven't read all the way through it yet)...but the chart below shows the AH rating of EAST PENN batteries...regular "wet" lead/acid and AGM type batteries:

[YuCrew]

Originally Posted by noelskii

Just looked at my battery and it is a CarQuest 94R70

PART NO: 94R70
CCA @ 0*F: 765
20 AH RATE: 80

Does this battery suck or what? Looking to replace it sometime this week...

My two choices are:

Bosch Part#: 49-850BAGM

AutoCraft Part No: H8-AGM

Both are around the same price... Any suggestions?

Thanks!

I went with the AutoCraft. check out this video to see how to get the LOWEST effective price.



https://www.youtube.com/watch?v=37L_tM2Mps0&t=1s



This video might also help you.

https://www.youtube.com/watch?v=Lwtzry962Ps&t=306s

[Entropy]

Just replaced mine with an Autocraft Platinum from Advance Auto Parts. Came out to $143 after a core refund. Programmed with Carly.

[miamipanther]

Our 2012 E70 just passed 100k miles today and got error P0890 "Traction Control Module (TCM) Power Relay Sense Circuit Low" several times and couldn't switch gear, the error cleared up after a few restarts of engine.

Searched online and suspected the battery(original) could be issue, measured voltge of the battery at 12.36v/14.8v(engine off/on). The off voltge seems low

Went with Autocraft Platinum from Advance Auto Parts, paid $130 + tax after 25% off and 8% topcashback.

Called dealership, they offered original battery at $400+, but $300 other 95ah battery with lifetime warranty.

Thanks this thread, Autocraft Platinum is exact fit according to AAP website although 95ah vs 90ah, and the dimension is identical.

Registered with INPA. It was a very easy swap and coding.

[Westlotorn]

Reading some of the posts above I think there are some misconceptions.
The Amp Hours are important so you have reserve capacity, these cars draw a lot of power and can drain a lesser battery.
The charging system as far as I know will charge any battery till it registers a full charge. This is controlled by the voltage reading not AH reading.

So if your system finds your battery less than 12.6V it will charge till you are at 12.6V.
Running the voltage is always higher than engine off so 13.9V may be common + or - a little.

My 08 4.8L came with an AGM, this technology was new to me at that time. I installed a 950 CCA wet cel battery. It did not work properly in this car.
After having a no start condition every time the car parked for more than 5 days I went and bought the AGM from Sams Club and the car has worked fine ever since.
I would need to look to see exactly what my CCA and AH are but it has worked now since 2012 so I am happy it has outlasted the OEM at this point.
The Wet Cel battery might have worked if I went to the dealer and had the car programmed for a Wet Cel but it was cheaper and faster to just buy a new AGM battery. I will confess I also found the car was receiving a signal from the passenger side mirror stating that it had an issue. The computer would not go to sleep because it kept getting this bad feedback from the mirror. The mirror worked perfectly this entire time. I pulled it apart and removed and cleaned the electrical connections and the mirror motor parts. Put it all back together and it has worked perfectly since and does not have any codes showing.
Any simple code error like I had with the mirror will cause rapid battery drain. Even with this bad code reading the AGM lasted days longer than the Wet Cel I removed even though both had similar CCA ratings. The factory program will keep running system checks till the battery dies even if something simple like the passenger side rear view mirror is the cause. This is stupid programming in my opinion but it is the way it is.
I believe the AGM's at Sams are made by Johnson Controls, they build very good batteries and also build all Optima batteries.

An AGM has the ability to give you full starting ability right up to the point where the battery is nearly dead. Wet Cel batteries can't do that, when the wet cel battery is getting drained the voltage available drops off considerably. I used to know the numbers but with 50% charge a wet cel would only give you around 12V while a 50% charged AGM will still give you 12.6 which helps your system work correctly at full voltage.

The AGM's can take a much faster rate of charge without damage so the car's computer needs to know what type battery is on board to offer the correct rate of charge.
In Heavy Duty Trucking the battery buyers don't care about AH, they want to know CCA and RC, Reserve Capacity. How long a battery can last before needing a charge.

Hope this helps someone.