I've been fighting parasitic battery drain (as is everybody else) forever, and have heard all the arguments/suggestions thereof, including replacing the consumer battery.
I purchased an Interstate (glass mat) 2 years ago, before I started noticing the drain problem. I had the battery checked and replaced once. The drain continued and i suspected the battery again after eliminating many other possibilities. I eventually had the battery checked again by Interstate twice and finally they AGAIN replaced it with a new one. The drain continues and I'm in hot pursuit of other possible issues. I've recently heard many claim that I need a MB battery because "the Interstate batteries always fail."

Is there any proof/wisdom in this claim?

 

Have you measured the drain on your battery?

If it is over a few 100mA then the brand of battery is irrelevant.

Have you tried locating the source of drain?

In another post you say you have a tracker. Find out how much that consumes.

300mA will completely drain a fully charged battery in 10 days.
If you allow a battery to fully discharge, then that battery is permanently damaged.

 

I've said this many time before and will say it again, there is simply no substitute in my experience for a genuine Mercedes battery. Don't get drawn in by claims of OEM and battery stats, I have tried 3 different types of new rear batteries and I found after a few weeks, I would get the 'convenience battery' warning for low battery on the dash, which then goes after about 12 mins.
Working in engineering and battery powered trains, I got to understand what goes into battery technology and approached Mercedes to ask about their supplier for their batteries, which was Varta. However due to the strict quality assurance that Mercedes demand, a Varta battery from a store is not the same as a Varta / Mercedes manufactured battery from the dealer. I can leave my car in the coldest Scottish winter for a month and she will start no issues, never using any battery tenders.
The cost is not that much more, in fact Mercedes gave me a discount as I explained the issues I had with the other batteries, so you could perhaps try the same !

Good luck!

 

theres been a slew of people bringing this fact to light recently. It's very true.

I have no idea what it is, couldn't tell you how or why. My dealer training told me MB genuine batteries are just the correct choice and everything else fails prematurely, warranty or not. Being stranded costs more than the difference of the battery as well as diminished and unreliable module performance.

 

I am glad more are understanding this. here is a video I did on it.

 

I stand by what I posted.

If there is excessive parasitic drain on the battery, it wont matter what battery you fit.

Check to see how much parasitic drain you have before investing in a new battery. Remember it takes up to 20 minutes, after locking the car, for all systems to go fully to sleep.

 

So true. Do things in the right sequence - check the current draw and that both batteries are charging before replacing batteries. 'Correct' quiescent current is around 60 mA but it seems this can vary.

I wonder how many owners suffered battery drain by parking their cars and not locking them? Car needs to be locked to go to sleep!

My car came with a new battery fitted by an MB dealer - but they fitted a non-MB brand battery. Predictably it failed after a few years.

 

How long does car last on battery between starts?
1 day?
5 days?
2 weeks?

Measuring standby amp draw is complicated on these cars due to all the computers booting up when you touch car.
There wasa good thread in one of these car sections that went thru step by step how to do it on a rather Young MB to keep the computer from re-booting when chcking.

No matter the battery they each have a certain capacity (think EV Car) before voltage drops too low to be any good at starting car.
So the more standby draw you have the less the standby time you have before she will not start.

Now back to how long does it last between starts? if you lt her sit for over 30 days - get a trickle charger designed for your battery type be it old school lead acid or AGM or Lithium.

 

The real test is in the cold months. but I know I can leave my car for 4 weeks + it will start right up. I have been away with work for 2.5weeks at the moment and will need to pick up my car at the airport so good test.

 

In the US, the MB branded batteries are made by Interstate. This is from my dealer parts guy. I replaced both my 8 plus years old MB batteries with new and all electrical issues were cleared up. Two years old now.
I drive mine once per month for 3 hour pleasure cruises. Without a battery tender, I have no issues with accessories available or starting. I keep mine locked in the garage and it doesn’t drain enough to give a warning.

PS. I was in my local Scottsdale Costco and noticed they carry Interstate batteries. I might check and see if they could fit r230 batteries next time I’m there.

 

if youre looking for parasitic draw and I'm always checking in SLK and SL cars because they have even more modules you're going to have to test the amps in the car while it's off. Anything running an alarming amount of current will tell you what module and therefore circuits are still operating. I have caught this with the SOS system, telephony, and hell even the distronic system.


Hope that helps, you're gonna check every single fuse, if you find something running, you're going to disconnect that module/system from power and you can decide what to do from that.

Another MB Genuine battery testimonial, we have the original battery in the GTS, we didn't drive it for 4 weeks, fired right up. Going on 7 years now.

 

For avoidance of doubt: Mercedes does not manufacture batteries. Batteries purchased at MB dealers are “Mercedes labeled” batteries.

Mercedes labeled batteries are most likely produced by the same supplier and to the same specifications as or original factory battery. This is the reason why in nearly all cases to buy parts from the dealer, especially electrical parts.

For avoidance of doubt: aftermarket parts are not the same quality as dealer purchased parts. It doesn’t matter whose name (Bosch, etc) is on any given part. If it wasn’t purchased at the dealer it is not the same quality.

Aftermarket parts are built to lower quality standards than factory parts. While meeting the bare necessity in terms of form, fit and some function. It’s the aftermarket business model.

 

Ive had an AGM Interstate consumer battery in my SL65 from last spring with no issues at all. . Prior to replacing the battery i did have a large draw from the command system & telaid. As others suggested, IMO checking the draw at rest is step #1