Mercedes batteries have no warranty... - Page 4 - PeachParts Mercedes-Benz Forum

jay_bob · #46 10-14-2020, 10:15 AM

Quote:

Originally Posted by Shern

How exactly does it “refurbish” them?
From what I understood, that would require a chemical process and a degree of industrial alchemy.

Well I deal with industrial battery systems to back up the controls I design. We use lead acid batteries, same chemistry as your car, except built like a boat/RV deep cycle battery.

We have usually either 48 or 125 V dc systems. The battery is kept constantly charged by a device known as a charger. It is sized to provide the power needs of the system while commercial power is available and an overhead to recharge the batteries.

The ‘float’ voltage is usually in the low 50s for a 48 V string or low-mid 130s for a 125 V string. Actually the ‘125’ is normally comprised of 60 2-volt cells making 120 V.

This is analogous to the alternator in the vehicle providing the electrical loads and recharging the battery. The alternator operates at the ‘float’ voltage of 13.8 to 14.4 V.

However over time the individual cells begin to degrade at different rates under use. The commercial chargers have a mechanism where the voltage is increased slightly to bring the lagging cells up to the same voltage level as the ones in the lead. This is known as the ‘equalize’ charge. This is done on a time schedule, or the smarter chargers detect the change in battery output voltage and initiate it automatically.

What I suspect the automotive charger is doing is an ‘equalize’ leveling charge. When the cells start getting out of balance, the lagging cells end up subtracting from the total string voltage. Thus reducing the available capacity of the battery.

Car electrical systems do not have any means for equalize charging. They only operate in the ‘float’ region.

Shern · #47 10-14-2020, 11:56 AM

Thank you for that explanation. It's really fascinating, I had no idea extra current could undue corrosion/sulfation.

Found this on Battery university:

Besides age-related losses, sulfation and grid corrosion are the main killers of lead acid batteries. Sulfation is a thin layer that forms on the negative cell plate if the battery is allowed to dwell in a low state-of-charge. If caught in time, an equalizing charge can reverse the condition. Grid corrosion can be reduced with careful charging and optimization of the float charge. (See BU-403: Charging Lead Acid)

With that in mind, what causes the eventual death of the batteries in your industrial systems? Surely the 'equalizing charge' doesn't work forever? Otherwise, It would seem a good home charger would keep one from ever needing to replace their car battery.

jay_bob · #48 10-14-2020, 12:08 PM

They don’t last forever, they need to be replaced usually on 5-10 year intervals depending on the facility’s criticality and attention to maintenance.

Yes the sulfation is the mechanism that causes the weak cells and the higher voltage can remove it so long as it doesn’t build up too much.

OM617YOTA · #49 10-14-2020, 12:20 PM

Quote:

Originally Posted by pawoSD

Duracell branded ones are usually made by East Penn, which are top notch. I'd bet you could get more than 5 years from it, probably more like 7+ years.

Just to come full circle on this one, my battery died this past year. Truck started slow for a couple months, and that was my warning. I recognized the warning and understood that this was my warning, and was hoping to make it through the summer, and nope. Went to start the truck one day and it wouldn't even try. Glad I only wanted to drive my truck, that I didn't NEED to drive my truck.

That's my lesson, heed the damned warning. Replace the battery when it tells you it needs it.

I got another East Penn. Catch y'all back in this thread in another 5 years.

pawoSD · #50 10-14-2020, 12:58 PM

Has anyone here bought a MB battery of recent from the dealer? Are they still a Varta-made replacement or are they just some random battery with a MB sticker on it?

Need to replace the almost 6 year old battery in my GLK before winter as its getting weak (original varta), battery tester I have flagged it to be replaced and cranking isn't as strong anymore. Scores a 520 CCA out of the original 800.

jay_bob · #51 10-14-2020, 01:10 PM

My wife’s 2014 ML is getting that little hesitation on cranking that is the dead giveaway for a weakening battery. I plan to get the replacement from the dealer so I will fill in the details in the next couple days. The SUV batteries are a pain to replace, under the passenger seat.

The later models display the voltage (and the 212/166 platforms give you an ammeter too). If your voltage declines into the mid single digits when you hit the starter you are on borrowed time.
211/164 with doors closed put key in I position, display on mileage, push trip odometer reset 3x rapidly.
212/166 same initial conditions, but push Ok and Phone at same time on steering wheel.

Screwdriva · #52 10-14-2020, 01:56 PM

I was quite skeptical about Mercedes Batteries coming with a 1 year warranty only when a Bosch came with 3 years.

It's been 5 years since I went with the Mercedes choice without a single miss. As was explained to me, suppliers give their best to the MB dealer spares network. Moreover, the star in the engine bay adds to the character in my view.

I'm going to get another MB battery for my other Classic when the previous owner's choice dies.

pawoSD · #53 10-14-2020, 03:28 PM

I'm lucky on the GLK, its super easy to replace. Right in the normal spot under the hood like on the 124 and earlier, and the only thing in the way is the cabin air filter housing which comes off with three quick clips.

vwnate1 · #54 10-15-2020, 03:14 PM

EastPenn batteries are sold at Autozone and others : https://www.eastpennmanufacturing.com/applications/automotive/

gatorblue92 · #55 10-15-2020, 06:20 PM

I'm going on 10 years on the Mercedes battery in my 240D. Granted the car is a garage queen these days but it still fires right up every single time.

pawoSD · #56 10-15-2020, 09:45 PM

Ended up buying a dealer-sold AGM MB battery for my GLK....Made in Germany, not marked anywhere by whom but most likely that means Varta like the factory one is. Super fresh battery too, manufactured in September!!

Was only about $7 more than a Duracell AGM at Batteries Plus, so I didn't bother. Still slightly bitter at those batteries for the fiasco I went through with my brother's W211 last year when one of them failed completely at 11 months old.

Shern · #57 10-15-2020, 11:03 PM

How much stock do you guys put in load testing?
I'm talking the autozone/napa freebie service. Is it predictive in any significant interval, or simply the drive home?

vwnate1 · #58 10-16-2020, 09:44 AM

It's a good way to test a battery *but*, few know how to do it correctly .

Mike D · #59 10-16-2020, 10:00 AM

Quote:

Originally Posted by vwnate1

It's a good way to test a battery *but*, few know how to do it correctly .

Or have the proper tester.

Mercedes batteries have no warranty...-shopping.jpg

vwnate1 · #60 10-16-2020, 10:04 AM

That's a nice one .

I learned using a carbon pile typ of tester .

As previously mentioned : if the battery voltage drops below 10VDC when you're cranking the engine after a full charge it's kaput although it may well keep going a while .

There are plenty of inexpen$ive gauges you plug into the lighter socket that will let you know what's going on .

I hate it when they just -die- in the middle of nowhere when you try to start.