SL/R230: Auxiliary battery replacement
#2
Senior Member
Get an AGM battery from your preferred local AutoZone/O'Reilly's/NAPA/etc.
Almost all automotive batteries in the US, regardless of brand, are actually manufactured by Johnson Controls or Exide, so there's not really as much variety as you might think (I think Optima makes their own).
Unlike standard flooded cell, AGM batteries don't produce explosive/corrosive gas under normal conditions so this is the type of battery to get to use in an enclosed space. AGM batteries can still produce these gases if they are put into an overcharge condition, so even though this is a very rare malfunction it's still a good idea to connect a vent tube to an AGM battery. Your car has a hole/grommet in the trunk floor right by the battery just for this purpose.
I got an Everstart AGM from Walmart a couple of years ago, does the job just fine.
If you drive your car less than weekly, I'd recommend setting up your auxiliary battery with a connector for a trickle charger/battery maintainer so you can easily hook it up when parked. These cars have a lot of systems that stay semi-awake while they sit, so if they're not driven very regularly to keep the auxiliary battery topped up they will throw error codes caused by the low charge state.
Almost all automotive batteries in the US, regardless of brand, are actually manufactured by Johnson Controls or Exide, so there's not really as much variety as you might think (I think Optima makes their own).
Unlike standard flooded cell, AGM batteries don't produce explosive/corrosive gas under normal conditions so this is the type of battery to get to use in an enclosed space. AGM batteries can still produce these gases if they are put into an overcharge condition, so even though this is a very rare malfunction it's still a good idea to connect a vent tube to an AGM battery. Your car has a hole/grommet in the trunk floor right by the battery just for this purpose.
I got an Everstart AGM from Walmart a couple of years ago, does the job just fine.
If you drive your car less than weekly, I'd recommend setting up your auxiliary battery with a connector for a trickle charger/battery maintainer so you can easily hook it up when parked. These cars have a lot of systems that stay semi-awake while they sit, so if they're not driven very regularly to keep the auxiliary battery topped up they will throw error codes caused by the low charge state.
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gaazmon (03-22-2022)
#3
MBWorld Fanatic!
My experience is not buying an aftermarket battery and stick the Mercedes Dealer battery its only a fraction more. I have tried three other supposed oem batteries batteries and even when new gave issues with "no convenience function'' due to lack of power and leaving the car for a few days. Since I replaced with the Mercedes Stock battery I can leave the car in the middle of winter for 5 weeks and it starts right up with no warning issues and has been strong for 3 years now. I use the car only once a week and no warning issues, I also do not need any trickle charging nonsense.
#5
MBWorld Fanatic!
I'm likely going to upgrade mine with an Odyssey H8 AGM. Second to none when it comes to stability, reserve capacity and warranty.
https://www.fcpeuro.com/products/aut...odyssey-49-950
https://www.fcpeuro.com/products/aut...odyssey-49-950
#7
MBWorld Fanatic!
Odyssey H6 AGM - https://www.fcpeuro.com/products/aut...odyssey-48-720
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#10
MBWorld Fanatic!
Costco has an Interstate H6 AGM, 3-year replacement warranty for about $160, Walmart's Everstart is about $170 with a 4-year replacement warranty. Given how hard these cars are on batteries, that warranty sounds pretty good.
#11
MBWorld Fanatic!
The MB battery is perfectly fine and the Odyssey is just a level above. To me, well worth the $60 difference for the warranty alone.
This is an AGM (Absorbent Glass Mat) battery rather than a conventional flooded battery, and there are some mixed opinions on whether an AGM battery needs to be vented.
Per Odyssey, their batteries do not need to be vented.
Source: https://www.odysseybattery.com/wp-co.../AM-ODY-OM.pdf
This is an AGM (Absorbent Glass Mat) battery rather than a conventional flooded battery, and there are some mixed opinions on whether an AGM battery needs to be vented.
Per Odyssey, their batteries do not need to be vented.
Source: https://www.odysseybattery.com/wp-co.../AM-ODY-OM.pdf
#13
MBWorld Fanatic!
Too many negative reviews for me to consider it. Given the R230's complex electrical system, I wouldn't cut corners on the battery.
If you are unfamiliar with FCP Euro, they warranty any part you purchase for life (i.e. the life of your ownership of the vehicle).
#14
Junior Member
Thread Starter
Yeah, I’ve purchased parts from them before. Was aware of their warranty policy. But didn’t think it was for batteries. Ok I think you’ve made a sale lol. Thanks brother ✊🏼
#16
Junior Member
On my SL I have used ACDelco AGM 48 batteries, and they have always worked beautifully. Only issue that I ever had was going flat when left offline for a long period of time (read 6+ months); but that is mostly my fault for leaving them connected and not trickled.
#17
MBWorld Fanatic!
#18
Junior Member
#19
Junior Member
Thread Starter
Ok lastly, what about the interstate battery? I’ve had them in my other MB as starter battery. This is for the rear “auxiliary” battery, it’s different right?
#20
Junior Member
Yeah, it is completely different in my car. First you have lots more room and this battery is responsible for absolutely everything else in the car outside of engine ignition. That is the roof, stereo, seat functions, suspension functions and basically every other device outside of igniting the engine.
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tziady (03-29-2022)
#22
Junior Member
#23
Senior Member
Guys, what can be different from battery manufacturers....?
Raw materials.!
All of them are using the same technology..!
Mercedes does not make batteries. They specify batteries as the rest of manufacturers and put their brand on it.....so a AGM 70 A/h, H^ 700/760 CCA should deliver the same performance regardless of brand. The difference will be in durability which is linked to quality of raw materials..!
I am happy with my Duracell and no problems whatsoever, but if you are like my wife who prefers to pay extra money for Tylenol, instead of the much cheaper Acetaminophen..be my guess....freedom of spending!
Raw materials.!
All of them are using the same technology..!
Mercedes does not make batteries. They specify batteries as the rest of manufacturers and put their brand on it.....so a AGM 70 A/h, H^ 700/760 CCA should deliver the same performance regardless of brand. The difference will be in durability which is linked to quality of raw materials..!
I am happy with my Duracell and no problems whatsoever, but if you are like my wife who prefers to pay extra money for Tylenol, instead of the much cheaper Acetaminophen..be my guess....freedom of spending!
#24
Junior Member
I highly agree with you, mostly. Esp. when it comes to differences between brand and generic drugs. Not only is some of the quality of the materials different; there are in some very well documented cases issues with difference in speed of absorption, quality of coating, and other factors that even in many states the doctor can ask for no substitution. Of course, some of it is paying homage to the drug rep that is paying for your kid's school new uniforms for their soccer team; but there are some real differences outside of the cynical beliefs. Some even experienced by me who is involved in the medical field and a life long patient.
#25
FCP lifetime battery warranty???
That means you must pay the postage, right? ...and for a heavy battery (49lbs!), that will not be a $0.76 postage stamp, you know.
Furthermore, the item has to be defective, and not just down a few volts (which seems to the cause of electric troubles, even though the battery checks out to be within the realm of a good battery).
Id like to hear from someone who actually has done battery exchanges with FCP to know if the cost of postage and FCPs definition of "dead battery" are showstoppers in their Lifetime Guarantee program.
Thanks.
Last edited by xerxes; 05-09-2024 at 05:48 AM.