The question says it all. My supplier is out of H6 size and doesn't know when they will be able to resupply. The build sheet says that my car came with a heavy duty battery but I don't know which battery that refers to or anything else about it.

I checked my convenience battery today it was reading 12.43 volts and when connected the battery maintainer is said that the battery was only charged to 57% of it's capacity. I last drove the car yesterday and I've been driving it every couple of days so IMO the battery shouldn't be low. The battery was installed a little over 3 years ago by a non MB shop but there is no brand label on it, only a manufacturer/distributor's name that I've never heard of. I haven't had any battery problems that I know of but I have had some peculiar electrical issues so I think I'm just going to go ahead and replace the battery.

 

Why is your "supplier" the only source for an H6 battery that's sold by every auto store and even Walmart?

 

I didn't check the stock at EVERY supplier but I did look at prices, warranties and customer reviews and my source (Walmart) is $40 to $300 cheaper than anyone else and has a longer warranty than anyone else ( 4 year vs 3 years and sometimes only 2 years) and Walmarts are located every where so if I need to exchange the battery later I can easily do that; unlike many other sources.

One example: the same H6 battery at Autozone is $214.99 and has a 3 year warranty. Walmart's price is $179 with a 4 year warranty. NAPA doesn't even show their price but their battery only has a 2 year warranty and the nearest decent NAPA is about 23 miles away and the nearest Super Walmart is about 5 miles.

FWIW I checked the battery again this morning after leaving it connected to the trickle charger over night and it now reads 12.69 volts and the charger says that it's at 80% of capacity.

 

A $215 / 36 month battery at Autozone works out to $6/month or $0.20/day to buy peace of mind. Everybody's budget is tight in the current economy, but a dead battery at the worst possible time and place (do batteries ever fail elsewhere?) will ruin your day. When your battery gives you warnings -- slow cranking, flickering lights, etc. -- consider yourself fortunate to act while there's time. Don't rely on some helpful Henry to lend you a jump start -- there's no way I'm connecting my car's electrical system to anyone else's. But you can borrow my phone to call a tow truck.

 

I would not buy a battery at Autozone. I would look at the battery in the car it should have a Group number or size on it, and buy that size. From WalMart or Sears, some place like maybe even a Mercedes dealer. Call and check prices. Batteries Plus has Duracell made AGM batteries, I've had good luck buying those for R230's. Benz dealer might actually have a good price on the battery, you don't know until you ask them. Jump start a Mercedes? I never do that. If a battery is dead, I disconnect it and charge or replace it.,

 

I haven't measured it but the current battery should be a group size 48, that is standard for H6s and I think that H6 is stamped on the label but I will double check before I buy something. The H7s (group 94R) are the size height and width as the H6 but about 1 1/2" longer. The H8 is larger but I haven't looked at the dimensions but other automotive forums discuss replacing the H6 with the larger capacity H7 or H8 in other make cars and trucks and they all recommend the swap as long as there is room for the larger batteries. I've already looked at all of the local battery sources (and Amazon) and compared prices and Walmart is at least $40 less than any of the others. And they have a longer warranty. I asked at the local dealer last week and they want almost $400 for a battery with a 3 year warranty. The present battery was bought at another nearby MB dealer in June 2021 and they charged $240 for it then. Between the new battery, a new ABC hose, and replacement hydraulic oil and filter, the total costs of that visit was $2465.52!

I agree with about jumpering those cars. There seems to be a correlation between people that have jumpered their cars and the BCM failures and fires. If I had to jumper one of these. I would disconnect the battery and jumper it and let it charge for a bit and then reconnect it. But AAA in my area also carry new batteries on their trucks and will install them for you so I would probably just buy one and have it installed on the spot, instead of jumpering the car. The H6s are used in a lot of the newer cars so AAA almost certainly keeps them on their trucks.

 

Have you had a bad experience with Autozone batteries?

 

Nope, I've never bought an Autozone battery but I don't want to use this expensive and complex car as a guinea pig. But I have had a number of bad experiences with batteries from Discount Auto Parts, now Advanced Discount Auto Parts. For over 20 years I bought batteries from them almost exclusively and they were generally good but about 20 years ago they switched suppliers (but not the brand name on their batteries!) and I had six battery failures in less than a year. All on new batteries, one on the same day that I bought the battery and two others less than a week later. These weren't batteries that wore out and that wouldn't start the car, these batteries that shorted out internally and the car would literally stop running right in the middle of the road! So now once I find a battery brand that I like and that are reliable; and a source that doesn't try to cheat me on core charges, warranty issues or other things, I stick with them. Right now, that's Walmart.

I typed out a reply specifically to your first post (#4) but for some reason it didn't get posted. But I compared the costs that you show in #4 verses the cost of ownership of a 3 year warrantied Walmart battery that costs $139 and the Walmart battery was $3.88 per month and slightly over 12 cents per day. And I know that Walmart will stand behind them so why would go somewhere else and buy a more expensive battery? And why do you continue to push Autozone batteries? (FYI Walmart's 3 year warrantied battery is $139 and is in stock. Their 4 year warrantied battery costs $179 but is out of stock. Given my choice I would buy the 4 year battery.)

And I'm still looking for an answer to my original question: Will an H7 or H8 battery fit in the R 230? I already know whom I'm going to buy my batteries from, so it's just a question of what physical size battery; H6, H7 or H8. Given the R 230's reputation for running down Convenience batteries I would like to install the largest capacity battery that will fit.

Update: I checked the car and the battery in it is an H6 and group size 48. I think an H-7 might fit but it would require some trimming of the battery tray and the hold down clamp so I will probably just go with an H6. I also checked the battery again a few minutes ago and even though it's still connected to the battery maintainer the voltage has dropped from 12.69 volts about 6 hours ago to 12.29! So I think I'm going to go ahead and install a new battery and I'll see if that corrects some of the strange behavior of some of the electrical devices. I want to install Tom Manning's BCM fuse mod so this would be a good time to do that too.

 

I would like to know this as well. I don't drive this vehicle much and after 3 years the battery is on it's way out again. I would rather put a larger one like the OP states. What I remember is it does have a placeholder bracket that locks it in place and prevents moving. I have, for example, on a 2014 E350 sedan that came with a H7 battery replace with a H8 battery since it had the space for it.

 

Well, LOL! There's no brand name label on the battery in my car but it says that it came from Best Products and the part number is H6-DLG. I looked it up on the internet and it turns out that Autozone sells them under the Duralast brand! Also somebody went to the trouble to scrap off the date sticker and the brand sticker off of the battery!

I have some of the repair receipts for this car and I have one showing that this battery was installed on 30 Nov 2023. That doesn't inspire me to buy any batteries from Autozone! The shop charged the previous owner $26.55 just for the battery installation. The price of the battery and other parts aren't shown but the total bill was $1,392.96. The same battery was replaced by a MB dealer about two years earlier.

Happily, the Nov 2023 repair included replacing the leaking valve cover gaskets ($420 just for labor) and the leaking transmission gasket and filter ($210 for labor) so hopefully I won't be having to do those in the near future. The shop only charged $140 per hour so it definitely wasn't an M-B dealer!

 

As has been posted elsewhere on this forum, about 2/3's of all car batteries are manufactured by 3 companies -- Clarios (formerly Johnson Controls), East Penn and Exide. These companies private label for Walmart, Autozone, Die-Hard, Interstate, Optima, etc., etc., etc. Even MB sources from one of these companies. What's the difference between a $180 Walmart battery and a $240 Autozone battery? Who knows? Only the corporate buyers who award the supply contracts.

Warranties differ -- some are pro-rated, others are full replacement. I have no vested interest in Autozone. But Autozone stores are everywhere, they always have the battery I need, their warranty is 3 year full replacement, and I've had good experiences with their batteries. I put an H8 Duralast Platinum (made in Germany) in my G550 last year, and it's been fine. Put one in my Rubicon also -- still strong after 3 years.

Folks on this forum think nothing of dropping $150 once a year on an oil change -- $450 over 36 months. Yet half as much every 3 years for a battery is unthinkable. Few people suffer breakdowns if they go 1,000 miles past their oil change. But a battery can die without warning and stop you dead in your tracks. I'm surprised dealers don't push battery replacement preventatively every 3 years.

I'd change battery brand label before trying to crowbar the wrong size into my car.

 

Nothing wrong with batteries from AutoZone, Advance Auto, etc.

What matters is that the correct size, type and spec is used.

For reference, my starter battery is a "Autocraft" from Advance Auto. It's 6 years old at this point and when tested a few months ago, is still showing 100% battery health / capacity.

 

Well, I can confirm that at least with the Walmart Batteries you're not going to get anything larger than a H6 into an unmodified R-230. I bought one today and it took me over an hour to install it. It was a very tight fit! It was so tight that the bottom battery clamp wouldn't lay flat and I had to hammer it into place. I've been putting batteries in cars since my early teens and this is by far the tightest fit that I've ever seen and took at least four times as long as any previous installation. I bought a battery tester a few days ago and have been repeatedly charging and rechecking my <1 year old AZ 750 CCA battery and both the tester and my battery maintainer said that the battery was good but most of the time it was only showing that it was at about 69% of capacity. Yes, even when it was "fully charged". I'm still having some electrical issues so I wanted to be sure that they weren't related to the battery so I bought a new 850 CCA four year warrantied battery (date sticker says 5/24) and I tested it and the battery tester says that it's at 100% of capacity but it didn't change any of the electrical issues as far as I can tell. Even worse sometime in the last two days the left front strut has dropped all of the way down and this morning it won't come up when i started the car and the dash is now showing a red ABC warning and it says not to drive it. I restarted the car a number of times but the message is not going away. The ABC fluid and filter and several lines were changed a couple of years ago and everything in the ABC system appears to be in perfect condition and there are no signs of any leaks anywhere. The ABC light cycles off and on when I press the ABC button but nothing happens with the system

BTW this battery and I assume other WM EverStart batteries are now made in China!!!! So as far as I'm concerned, all bets are off as far as the quality of the WM batteries. But we'll see how long this one lasts.

 

Before I finally stopped buying batteries from ADAP about 15 years ago, I checked their "Autocraft" batteries and they were all made by Johnson Controls! And most of the batteries in ADAP at that time were made by JC. Look at the bottom of your battery and see who made it.

 

Oh and BTW, I found the vent hose laying loose in the back of the battery compartment. Evidently the last battery installer left it off. But the WM battery does have a vent hole in the end of the battery so I installed the tube and run the other end out through the grommeted hole in the floor of the trunk. I know there has been discussion about whether or not modern batteries have the vent hole but I can confirm that the 4 year WM H6 battery does so FYI.