Adi-Benz

Here's my video DIY of the replacement, of course its very straight forward:


Link of battery used in description. $40 replacement vs $130 OEM battery, and of course not including dealer premium.

Hope this helps.

DFWdude

Nicely produced. Thanks, Adi...

Adi-Benz

I appreciate it!

Left Coast Geek

did the overflow drain work?

Adi-Benz

Vent tube? Or are you referring to something else?

bmwpowere36m3

Yes, it seems the replacement lacks a connection for the vent tube.

Adi-Benz

From what I understood, is this was a sealed battery as opposed to the vented, however I will look at it tomorrow when I get a chance.

kajtek1

This is "non-spillable" battery. Doesn't need drain tube.

Adi-Benz

Regardless, I will add a disclaimer.

I know the reasons behind venting and whatnot, so I will leave it up to individuals choice. Between this and pricier alternative replacements without vents, there were no reported issues.

If you do not know, venting is important for batteries in passenger compartments; because this is in the trunk, *technically* it counts. While the battery style is slightly different (eg agm etc) if you are more comfortable with OEM battery, you can still purchase direct replacement on Amazon.

kajtek1

The main purpose for designing AMG batteries was to make them non-spillable, so they can work upside down and on its side.
I have AMG batteries with no hole in them and looks like the one here doesn't have it neither?
Why some AMG batteries have vent hoses? Beats me. I would not loose sleep over it, especially with battery in the trunk.

Left Coast Geek

AGM batteres are also known as Valve Regulated Lead Acid. NORMALLY they don't outgas but if they overheat due to bad conditions, they can outgas and those gasses are highly corrosive.

Alandf

We have cars that cost over 60K new. I bought mine used for 35K. Why would I try to save $100 or so on an aftermarket UNVENTED battery.
It cost me over $70 just to buy gas yesterday in CA

I don't get it

Adi-Benz

For the same reason some of us do our own oil changes...I personally don't care if I use Mobil-1 instead of Mercedes-Benz oil, as long as it is the same spec and performs similarly.

It's evident that there are thousands of people using similar batteries, if there was a problem, we would definitely have seen it. People are more likely to post when something goes WRONG than write a good review.

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bmwpowere36m3

I enjoy DIY'ing and "saving" money in labor, but not necessarily the parts. OEM alternatives vs. OE, definitely. Joking about saving money, because for me the amount of money invested in a garage, tools, etc... realistically I could pay someone to do the work and be ahead for a LONG time hahaa

I'd be inclined to find a Yuasa battery of similar spec. My experience with these off-brand batteries on Amazon is really hit or miss (not with Start/Stop).... I bought a few AGM VRLAs for my dual sport bike and they last all but 6 months before not wanting to take a charge ($40 vs $100 for Yuasa).

rapidoxidation

Not to mention explosive. Maybe going Hindenberg is a German thing (wait... our cars are German) but hydrogen gas burns nicely given a chance. Not to rag on the OP but I've always considered it worth getting the best I can afford. I can afford this car, I can afford the proper parts to keep it in good trim.
Edited to add: Auxiliary not auxillary

kajtek1

There has to be a limit to everything. I am religious about buying MB fluids. That is something I can't test or measure, while buying cheaper equivalents can have disasters results.
Typical is that owners put Zerex coolant for $5 savings. I often drive in 120-130F environment and my cars never overheat, even when they do have high mileage.
I just got $3800 estimate for my Sprinter exhaust leak repair. Did I go for it? NO WAY ! I am buying $170 flex pipe and will have muffler shop cut off the old one and weld aftermarket copy.
When it comes to this battery - again this is no spill battery that doesn't have vent. Maybe it is better design than OE battery?
Regardless the MB batteries don't have good reputation, so if that one will last 3 or more years it makes lot of sense. Not like aux battery failure will stop you in your travel.
One more note - if you have alarm system in your house, you do have 1 of those batteries somewhere in your closet. Is it vented?
Same with computer backup power.

Adi-Benz

Well, that's the point of me posting on a forum I guess. To think outside the box, do something different, get some constructive criticism.

You guys and Geek had constructive criticism. If people didn't know, they learned something, as well as now you've got the idea to pursue a different option. That's why a forum is best, it's /usually/ people who know more things in depth about the car than the average owner, or "Facebook group" member. If I wanted those kinds of low level comments, I could go elsewhere. What am I supposed to say, my car is more expensive than his? Does that help anyone? Nope. Constructive criticism is different than shallow criticism.

Obviously I will be the test bunny for this battery. You can take a look at my posts and "thanks" and you'll see I'm not going anywhere. I'll gladly update this thread when anything changes. As for now, I'm confident in the replacement.

Adi-Benz

Another thing I noticed during my research is there is at least 3 different companies that made the oem aux batteries. Mine was made in Thailand, I don't remember the other 2 or any differences, but they might be different depending on where the vehicle was made...

CaliBenzDriver

go look in the trunk where the 2x fat red cables meet: this is a fat RELAY with old fashioned contact points (not solid state) and given a chance a spark!

I don't think the air in area around the spare tire is at all vented the way both trunk sides are with flaps.

The Ingineeers idea to route AGM gases outside serves as warning. These AGM batteries can see deep cycle duties and some over-charge if the car charging system goes crazy. There is no battery sensor on the rear auxiliary to measure Temp, current to stop a runaway condition.

The load current out of this battery is in the 30 to 50Amp range when it supplies the whole car minus the starter 100Amp. load.load.... keeping a proper vent tube looks like a good policy.
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Adi-Benz

There are rubber plugs on the metal with some small holes near them, and the hose will still serve as a port for gasses, not acid
that relay is tucked away as well

I believe air is exhausted underneath the rear window from the cabin into the trunk and out the rear wheels. There will never be enough buildup of gases for anything to occur. You're really looking for a perfect formula; I'm not saying it can't happen but I don't think exaggerated circumstances will occur in most cases

Adi-Benz

Also I have just noticed that the new OEM replacement batteries state they are "AGM upgrade for vehicles equipped with lead acid battery..."

CaliBenzDriver

AGM are gel lead-acid batteries... when you pick a part replacement it's a good idea to match specifications.
Here the Amp/hour load rating is key

Adi-Benz

Yes, but if it's "upgraded" as "sealed" then that would make 4 variations of the battery already

pierrejoliat

https://www.sciencedirect.com/topics...sion:sadwavey:

Adi-Benz

https://mbworld.org/forums/sl-class-...ole-where.html