Recent Topics
Advice on spark plugs for 90,000 mile Accord
by Chris B.. 12/13/18 11:24 PM
Elec star kit for predator engine...
by SmokeyBear. 12/13/18 11:07 PM
Mecredes Bosch vs Ngk sparks plug
by Rohan. 12/13/18 09:48 PM
Wife problem?
by penguin. 12/13/18 08:04 PM
2008 Chevy Malibu 3.6L V6
by lordcheeto. 12/13/18 07:36 PM
power company merged and I got the shaft
by motor_oil_madman. 12/13/18 07:19 PM
Space heater burnt smell
by BossMoss. 12/13/18 07:13 PM
Shell Helix Ultra Maserati 10W-60
by wemay. 12/13/18 06:53 PM
Cox Modem Info???
by Gebo. 12/13/18 06:39 PM
How are these Road Force values?
by mclasser. 12/13/18 05:19 PM
Finally broke down a bought a trailer
by BeerCan. 12/13/18 04:25 PM
What oil for '19 Subaru WRX?
by TKNY. 12/13/18 04:12 PM
Splitting wedges
by buck91. 12/13/18 04:00 PM
Avoiding rust in the rust belt states?
by Chris B.. 12/13/18 03:00 PM
Newest Members
Ericbrooks, Japanese, lordcheeto, WondrousBread, slickoo9
66672 Registered Users
Who's Online Now
38 registered members (Bailes1992, CB900F2, 92saturnsl2, bmod305, 53' Stude, 19VWJettaS6speed, 5 invisible), 859 guests, and 46 spiders.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums67
Topics295,047
Posts4,926,782
Members66,672
Most Online2,553
Oct 27th, 2018
Donate to BITOG
Previous Thread
Next Thread
Print Thread
Hop To
Page 1 of 2 1 2
Looking for Group 48 Battery with 74aH rating #4620966
01/01/18 06:13 PM
01/01/18 06:13 PM
Joined: Aug 2004
Posts: 20,204
CA
The Critic Offline OP
The Critic  Offline OP
Joined: Aug 2004
Posts: 20,204
CA
Application is a 2012 MB C250.

Most C-Classes of this generation use a 94r battery, but this particular vehicle uses a group 48. However, all of the group 48s I can find carry a 70aH rating, not 74.

This is the original battery from the vehicle:




Upgrading to a 94r battery would require new hold down hardware and I would like to avoid this if possible.

Any ideas?

Last edited by The Critic; 01/01/18 06:18 PM.

2011 Toyota Prius - 178k - Various 0W-20 (Brew)
2007 Honda Accord 2.4 - 133K - Mobil 1 EP HM 5W-30
Re: Looking for Group 48 Battery with 74aH rating [Re: The Critic] #4620995
01/01/18 06:34 PM
01/01/18 06:34 PM
Joined: Aug 2012
Posts: 3,041
Cincinnati
donnyj08 Offline
donnyj08  Offline
Joined: Aug 2012
Posts: 3,041
Cincinnati
Can you get the correct unit from a Mercedes Dealer?


2008 Silverado Z71 LT 90k Maxlife FS 5w30
2010 Ford Escape 172k QSUD 5w20
2016 Yamaha XSR900 12k, Rotella 15w40 Yamaha Filter.
Re: Looking for Group 48 Battery with 74aH rating [Re: The Critic] #4621017
01/01/18 06:53 PM
01/01/18 06:53 PM
Joined: Dec 2017
Posts: 417
Massachusetts
VeryNoisyPoet Offline
VeryNoisyPoet  Offline
Joined: Dec 2017
Posts: 417
Massachusetts
Is it a listed requirement from MB to have 74 aH?

Unless there's a special case, the aH rating of a starting battery is not super important. The aH rating of lead-acid batteries is measured at a slow discharge rate, usually over 20 hours for deep cycle and 10 hours for starting batteries. This may be useful for running light to medium loads over a long time, but not for running an engine and accessories in case the charging system suddenly fails.

The faster a battery is drained, the lower the efficiency and the less apparent capacity it will have (the Peukert Effect). The reserve capacity (RC) is a better measurement for a battery in automobile service, as it is how many minutes the battery can sustain a 25 amp load before it discharges below 10.5 volts when at a temperature of 80 degrees F (26.7 degrees C). 25 amps is a pretty typical load of a car with engine running and headlights on, and below 10.5 volts many systems like engine management and transmission controls will begin to malfunction. RC is a good test of how far a car with no charging system can be limped along at night before becoming inoperable.

My guess is any quality brand group size 48 or H6 battery will fit your application. If the car was ever using anywhere near the full aH capacity of the battery, it would be destroying them in a matter of months since lead-acid chemistry does not tolerate repeated deep cycling like that.


1998 V70 GLT / 195k miles [10w-30 Valvoline Syn w/ Maxlife Tech + Mann W917 filter]

"Use yah blinkah!"

"Be nice. The alternative involves an air horn and 7000 lumens of high beam."
Re: Looking for Group 48 Battery with 74aH rating [Re: The Critic] #4621035
01/01/18 07:07 PM
01/01/18 07:07 PM
Joined: Apr 2017
Posts: 1,428
San Rafael, CA
dogememe Offline
dogememe  Offline
Joined: Apr 2017
Posts: 1,428
San Rafael, CA
it doesn't matter. be sure to get an agm battery


2010 Ford Escape 2.5 ~91K Miles: AMSOIL SS 5W-30, AMSOIL SS FE ATF.
1995 Chevy Silverado 5.7 ~277K Miles: Delo 10W-30, AMSOIL OE MV ATF.
AMSOIL
Re: Looking for Group 48 Battery with 74aH rating [Re: The Critic] #4621041
01/01/18 07:11 PM
01/01/18 07:11 PM
Joined: May 2010
Posts: 9,469
out there
spasm3 Offline
spasm3  Offline
Joined: May 2010
Posts: 9,469
out there
I wonder if that spec is fudged so that you buy it from MB? All the group 48 batts i see are 70ah. I'd just go with a reputable brand that has enough cca.


13 elantra 72k 5w30 QSUD
03 chevy avalanche 80k synpwr 5w30
17 mazda cx-5 7300 miles m1 0w30
Re: Looking for Group 48 Battery with 74aH rating [Re: The Critic] #4621086
01/01/18 07:43 PM
01/01/18 07:43 PM
Joined: Oct 2014
Posts: 2,543
San Antonio, TX
Nyogtha Offline
Nyogtha  Offline
Joined: Oct 2014
Posts: 2,543
San Antonio, TX
You could contact Exide, who has links to First National Battery in South Africa, shown on your pic of the battery, and see what Exide recommends.

http://www.exide.co.za/what-we-do/

There appears to be only one 74aH 20 hour capacity battery listed in their Products section.

http://www.battery.co.za/products/automotive/passenger-vehicles/?rangeID=3&batID=66

Personally for only 5.4% difference, I'd just get the Bosch Group 48 (H6) AGM at Pep Boys while it's 30% off instead of chasing something from another continent. I put one of these in my wife's Mustang as an upgrade to the factory Group 96R and it's working great.

Pep Boys Link


"No matter how paranoid you are you're not paranoid enough. Tell the truth. Reach as many people as you can with it. That's your weapon." - Susanne Modeski, aka "Holly" to The Lone Gunmen
Re: Looking for Group 48 Battery with 74aH rating [Re: The Critic] #4621093
01/01/18 07:49 PM
01/01/18 07:49 PM
Joined: Aug 2009
Posts: 3,920
Pittsburgh,PA U.S.A.
JimPghPA Offline
JimPghPA  Offline
Joined: Aug 2009
Posts: 3,920
Pittsburgh,PA U.S.A.
A decrease in Amperhours of 5.4% (4/74) will never be noticed, ever.

Just get the 70 Amperhour battery and forget about it.


Boy will I be happy when ALL vehicles on public roads are autonomous.


JimPghPa

Re: Looking for Group 48 Battery with 74aH rating [Re: The Critic] #4621094
01/01/18 07:50 PM
01/01/18 07:50 PM
Joined: Jun 2003
Posts: 33,564
ME
eljefino Offline
eljefino  Offline
Joined: Jun 2003
Posts: 33,564
ME
74 aH until what happens? The battery reads 11.5 volts? Car fails to start? At what temperature? After what charging voltage? At what discharge rate?

As specs go Mercedes may be playing a different game than the aftermarket.

Re: Looking for Group 48 Battery with 74aH rating [Re: The Critic] #4621214
01/01/18 09:44 PM
01/01/18 09:44 PM
Joined: Jul 2011
Posts: 756
MO
wkcars Offline
wkcars  Offline
Joined: Jul 2011
Posts: 756
MO

Re: Looking for Group 48 Battery with 74aH rating [Re: The Critic] #4621235
01/01/18 10:14 PM
01/01/18 10:14 PM
Joined: Oct 2014
Posts: 2,543
San Antonio, TX
Nyogtha Offline
Nyogtha  Offline
Joined: Oct 2014
Posts: 2,543
San Antonio, TX
^^^^ WHOA!

$356.99 for a 1 year free replacement plus one year prorated warranty AGM!

Plus shipping?


"No matter how paranoid you are you're not paranoid enough. Tell the truth. Reach as many people as you can with it. That's your weapon." - Susanne Modeski, aka "Holly" to The Lone Gunmen
Re: Looking for Group 48 Battery with 74aH rating [Re: The Critic] #4621603
01/02/18 10:47 AM
01/02/18 10:47 AM
Joined: Aug 2004
Posts: 20,204
CA
The Critic Offline OP
The Critic  Offline OP
Joined: Aug 2004
Posts: 20,204
CA
Thanks everyone.

You folks are probably correct that 70 aH vs 74 aH does not make a difference in the real-world. However, Euro cars have very finicky charging systems which use the battery's aH rating to determine the correct charge rate. For instance, BMW requires re-coding of the vehicle if you change from a standard battery to AGM (or vice-versa) and/or if you install a battery with a different aH rating. I scanned this car with my Autel and did not see an option to re-code the car for a different battery type or aH rating, so it is possible that MB's charging system is not as picky.

Based on the car's VIN it looks like there are 3 possible hold-down brackets depending on the battery size. Unfortunately there is no way to tell which hold-down applies to a particular battery size - that is just the nature of MB. MB only lists battery part numbers in their database, not group sizes. I think I need hold-down #204-628-01-41 but I am not entirely sure. The hold-down bracket is a few days away.

However they did have plenty of the unicorn 74aH rating batteries in-stock for $162 msrp.

Last edited by The Critic; 01/02/18 10:50 AM.

2011 Toyota Prius - 178k - Various 0W-20 (Brew)
2007 Honda Accord 2.4 - 133K - Mobil 1 EP HM 5W-30
Re: Looking for Group 48 Battery with 74aH rating [Re: The Critic] #4621827
01/02/18 02:21 PM
01/02/18 02:21 PM
Joined: Jan 2004
Posts: 4,459
California
nthach Offline
nthach  Offline
Joined: Jan 2004
Posts: 4,459
California
What does the customer want? More Ah is a good thing in moderation - but if the goal is to get a bigger battery for easier availability and if the customer agrees with it, I'd swap in the new bracket.

Otherwise, I'd install the 74Ah MB battery. The good thing about German cars for the most part that the battery lives in the trunk or under the back/front seat and it's decently protected from temperature swings. Now if Mercedes is using a "micro-hybrid" charge on deceleration system like BMW and Hyundai does, well the battery will still be punished.

Re: Looking for Group 48 Battery with 74aH rating [Re: The Critic] #4622026
01/02/18 05:47 PM
01/02/18 05:47 PM
Joined: Aug 2004
Posts: 20,204
CA
The Critic Offline OP
The Critic  Offline OP
Joined: Aug 2004
Posts: 20,204
CA
This one lives under the hood.

Owner decided to go with the MB battery. Not sure who makes it- there are no telltale markings on the battery. There isnít even a date code. The parts guy said Interstate is the distributor, so maybe it is a Johnson Controls battery?



2011 Toyota Prius - 178k - Various 0W-20 (Brew)
2007 Honda Accord 2.4 - 133K - Mobil 1 EP HM 5W-30
Re: Looking for Group 48 Battery with 74aH rating [Re: The Critic] #4622195
01/02/18 08:34 PM
01/02/18 08:34 PM
Joined: Oct 2014
Posts: 2,543
San Antonio, TX
Nyogtha Offline
Nyogtha  Offline
Joined: Oct 2014
Posts: 2,543
San Antonio, TX
How about under that MB sticker in the upper left area? Looks like another sticker underneath that might have some info.

What kind of warranty does that battery come with? Interesting no date code.


"No matter how paranoid you are you're not paranoid enough. Tell the truth. Reach as many people as you can with it. That's your weapon." - Susanne Modeski, aka "Holly" to The Lone Gunmen
Re: Looking for Group 48 Battery with 74aH rating [Re: Nyogtha] #4622235
01/02/18 09:22 PM
01/02/18 09:22 PM
Joined: Aug 2004
Posts: 20,204
CA
The Critic Offline OP
The Critic  Offline OP
Joined: Aug 2004
Posts: 20,204
CA
Originally Posted By: Nyogtha
How about under that MB sticker in the upper left area? Looks like another sticker underneath that might have some info.

What kind of warranty does that battery come with? Interesting no date code.


If the battery was for my own car I would have peeled off the sticker to check, but it is for someone else's car.

MB policy is 2 yrs/unlimited mileage, no pro-rate.

"2.2 Any replacement battery purchased on or after August 1, 2000 at total customer expense is covered for a warranty period of 24 months, unlimited mileage from the date of purchase. Warrantable repairs will be made at no charge for parts and labor when performed at an authorized Mercedes-Benz Center (Passenger Car or Light Truck, as applicable). "

https://www.mbwholesaleparts.com/warranty.aspx

Last edited by The Critic; 01/02/18 09:24 PM.

2011 Toyota Prius - 178k - Various 0W-20 (Brew)
2007 Honda Accord 2.4 - 133K - Mobil 1 EP HM 5W-30
Page 1 of 2 1 2

BOB IS THE OIL GUY® Powered by UBB.threads™