JettaRed

iTrader: (1)

Yep, I was joking. The pics you posted showed the batteries disconnected.

Anyone have any idea what the plastic cage really does other than trying to keep owners from doing their own batteries?

ThatsMyDawg

Cool. I am so used to seeing a j/k or a after some ribbing, so I wasn’t sure lol. I didn’t think to snap a pic until after I was already doing the disconnect. I think you may have nailed it on the cage. Make it tuff for customers and they will just pay us to do it. MB

octony9717

This is what I see in my trunk, might be my sound system parts. I have the B&O upgrade. Looks like I need to keep digging the trunk panels to get to the main battery.

I've been using AAA battery service for all my cars over the last decade. I can see that I will have to use a more knowledgeable tech than the AAA guy if the battery problem is more than a jump.

rorywquin

I don’t see a tyrefit kit. Are you driving on runflats or is it stored elsewhere?

rorywquin

Good job.

Did you need to use a power saver or did you swap the batteries one at a time?

How difficult was it to remove that plastic cover over the fusebox & aux battery. I saw a YT video where the guy actually cut off two lugs on the right.

ThatsMyDawg

Thanks!
I did not need to use any power savers. Did the little Aux battery first and then the main battery in the trunk. Super simple.
As for the plastic cover, that was the hardest part of the entire aux swap and it wasn't even that hard if you just think it through. I did not cut anything, because you do not need to do that. The guy in the video was just impatient. The tabs on the right closest to the console can be pushed free, but you need both hands, so one hand can clear the space and the other hand can push. Once you get those two free the cover starts to move pretty freely. You just have to do similar on the left side then it pulls out at an angle. Not saying you can't cut it, but it is not needed.

MB wouldn't cut those tabs on each aux replacement and put on a new cover.


Yes, you will have to take all of those items out of your space and then pull up the liner that will expose your battery and your tow eye hook. I can't tell by your pic if some of you audio upgrades are attached on top of the liner, but hopefully they can just unscrew and move without disconnecting any wires if the audio upgrades are on top of your liner.

Remember everyone. An easy way to know the order to disconnect and reconnect batteries are.....

When subtracting a battery from your car you remove the - cable first. (Subtract) When adding a battery to your car you connect the + first. (Add)You will never forget with this mind trick..

JettaRed

iTrader: (1)

Just pull up the black formed piece. The battery is under the part that looks like where you would set two beverages.

I find the enjoyable part of owning a car like this IS to know it better than most people.

octony9717

Run Flats at the moment.

rorywquin

As long as the car is negative to earth/ground.

rorywquin

I found how it is done. MB would remove the speaker panel to the left of the battery (looking at it with your back to the dashboard). However that involves moving the trim above teh speaker panel, the sill and the door rubber.........I managed to snap a tab removing mine and will cut off those tabs to make future jobs easier.

JettaRed

iTrader: (1)

Wrong side of the road. Wrong polarity. The colonists that established the United States must have really been pissed at the king.

(Or, they were all left-handed.)

Jcrew

ThatsMyDawg: 30 minutes total for both batteries? Impressive. I will be doing mine (2016 with originals) this summer and have a question. Did you have to clear any codes or do any reprogramming when you finished? For example, the windows may need their limits reset……
Also, did you purchase OEM batteries from the dealer or go aftermarket?

ThatsMyDawg

Yep. It would have been quicker but it took extra time to figure out how the battery cover comes off without cutting it.

I did not have to reprogram anything. Windows, top, or whatever still works like normal. As mentioned prior as an added benefit my magic sky seems to transition quicker than before, but that could just be my perception and not reality. I purchased both from the dealer. MB Hunt Valley. As a matter of fact I still have to return my main battery and get my $25 core back!! Doing that in the morning.

rorywquin

I’ve got mine out and am reasonably convinced that it is meant to be load bearing in-case people sit on it (kids) or put heavy luggage or other weight on it. There is some sensitive gear in there especially those two plugs (on top)with the wires (fibre optic) coming out vertically. I often put my shopping bags on it (sometimes full of wine bottles etc).

rorywquin

How did you get that heavy duty cover out & back so quickly? I struggled for ages to get it out..

ThatsMyDawg

I looked at it days prior to get an understanding of how it works. By the time the actual day came to pass I had an understanding of what to do. Taking it off took longer than putting it back on.

JettaRed

iTrader: (1)

I got my batteries from FCP Euro since if I ever need to replace them again, it cost's only shipping to "exchange" them with FCP.

The big battery was an Odyssey Group 49 H8 Battery (ODY-49950) as those are highly rated and had the required CCA for our cars. Not all Group 48 batteries do. https://www.fcpeuro.com/products/aut...odyssey-49-950


For the little battery, I went genuine Mercedes (MER-000982960825). However, though it is a substitute, the terminals were a little different. I could still connect but could not get the small cover for the batter on, so I left it off. The big plastic cage covered it anyway. https://www.fcpeuro.com/products/mer...mer-0009829308

rmorin49

I think the plastic cage is typical German over-engineering. Clearly it was designed to hold down the battery in the event of a catastrophic accident, like a multiple rollover.

rorywquin

I disagree.

Before retiring, I worked in the engineering (design related) business & worked with design teams for my whole career.

1) The whole design is engineered to take a load from the top.
2) The battery is bolted to the chassis via it’s own clamps, and has it’s own separate protective cover.
3) The battery is restrained in a way no better or worse than the (bigger) battery in my wife’s B-Class which is in the floor under the right side (passenger in the US) feet.
4) Looking at the cover (right side in photo faces forward) at the points I have indicated in red, these are clearly load bearing and rest directly on the chassis.
5) The reinforcements webs (some are yellow highlighted) designed into the cover, are for load bearing & stiffness strength. Even the ‘u’ shaped tab at the bottom left is designed to take weight from above. An adult could stand on it and it would not budge.
6) Looking at the area at the top of the photo which would normally be located over the battery, there is nothing there to prevent the battery moving because it is already securely held in place.

JettaRed

iTrader: (1)

Interesting. Have you looked at the other side where there is a storage cubby? Is it similarly reinforced?

rorywquin

No - have you? Be interested to hear what you find.

From what I can see in the first attached picture (ignore the blue circle - it was in the picture I copied), the storage box looks pretty substantial to me - perhaps for the same reason. The dont want it to collapse if weight is put onto it.

I couldn’t find pictures for the R231 but two attached of the R230 rear storage box (URL attached for a bigger view), look pretty substantial to me.

https://www.ebay.co.uk/itm/123996310...BoCFDAQAvD_BwE

JettaRed

iTrader: (1)

Somebody a little cranky today? Need some coffee? ☕️ (j/k. I was being lazy. mechanical engineering was one of my poorer studies in college.)

I found an owner's manual, a fuse chart, an iCarsoft MB V3.0 scan tool, a PowerGate3+ handheld OBD programmer, two loaves of bread, a quart of milk, and a dozen eggs. 🍞🥚🥛

rorywquin

I’m sorry you misunderstood my reply and jumped to a conclusion about my demeanour .

You asked a question which, I answered and provided some additional information.

I then asked you a simple question which you have not answered.

JettaRed

iTrader: (1)

No worries. I'm sure it's just an English/American thing.

I found all of that stuff in my cubby (the eggs, milk, and bread were a joke). Structurally, I haven't looked yet. It's 8:50 am here, the crack of dawn for us retirees.

rorywquin

Don’t worry.

I’m not English or even British.

However, a lot gets lost in translation with the written word.