mcbridebr

Hey everyone! I have a 2012 GLK 350 that is FINALLY having its original to me AGM battery fade out on me. Twice now it has failed to start and needed to be jumped off. Drove it yesterday off and on and it sat over night. Went out to go somewhere and it would not start again. Tested today with my multimeter and its sitting between 12.2 and 12.1 volts, guessing its shorting, idk. But I think its time to replace it since I have had to jump it off twice in the past week. Mercedes OEM AGM aside, anyone on here have any luck or experience using other branded AGM batteries?

Mmr1

Wow about 14 years. A weak battery can ruin computers and cause other problems. FCP euro sells Odyssey AGM batteries , from what I’ve read I think at consumer reports Odyssey is maybe the best battery . FCP has a life time warranty so you can move it to your next car. They honored a warranty claim of mine.

I will have an Interstate AGM, 4 years on it holds 99-100% charge . Whatever you get charge it with a charger first .

calder-cay

You must've read different reviews than I'm looking at right now. A number of folks complained of complete failure (of an Odyssey) within a year.

And guess what? FCP Euro does NOT pay to return the battery - you can imagine what it costs to ship a big ol' battery 👍

My recommendation? Buy from a reputable nationwide auto parts chain - that way, if the battery conks out, you're not gonna be stranded WAITING on a new battery shipped to wherever you are.

The Aux battery on our 2015 350 was throwing the "Aux malfunction" message on the dash, so I drove (GLK) to a nationwide auto parts store (there's 5 different stores within 5 minutes of each other) and bought a new Aux battery. I changed it out in the parking lot in about 5 minutes (I wanted to give them my old battery while I was already there).

Similar event with our Jeep. Main battery went bad, so I yanked it out, drove up (in GLK) to auto parts, and walked back out with a new battery (the bad battery was under warranty at the auto parts - a no cost exchange). 30 minutes later, Jeep back on the road.

Odyssey reviews:
https://www.fcpeuro.com/products/aut...4r-850#reviews (yea, it's for my year model GLK)

mcbridebr

Thanks for the feed back for sure. Im trying to decide if its actually the battery now. Since posting I took it to Advance to have them check the battery and charging system.Advance Auto battery test showed it was fine but I dont know...

Driving data shows 14-14.8 volts and current +2.9 to +7 or +8. Charging system seems fine. Sitting off in the driveway voltage drops to 12.0 to 12.2. Current sits at -11.2 after settling down a bit. From what I have seen I THINK that is normal.

I feel like it still might be a bad battery. Advance Auto guy said his machine said the batter was at like 600 CCA but its rated for more than they and it said it needed a charge.

calder-cay

12 years on an original is great to read. Our 2014 GLK350 Base still has its original main battery (Aux has been replaced), so we're at 10 years.

You really need to have the battery load tested. Yea, a multimeter can give a clue, but a load test is better. If you don't have one, most all auto parts stores will load test for no cost.

Personally, I put a trickle charger on all our vehicles (even the zero turn ) every two weeks, simply as a maintenance item.

Unfortunately, we've yet to replace the GLK's battery, so can't speak from experience and provide a recommendation - but our day will come. I suspect I'll probably buy an original spec MB battery (10 and 12 year is a nice long life for a battery). However, I will do research, such as yourself, for other [less expensive and readily available] options.

mcbridebr

Actually check my comment above yours. I ended up having it load tested. Im even more confused ha.

calder-cay

I was busy typing

What did you use to get those readings? From the GLK on-board system or using the multimeter / scanner ?

mcbridebr

I used the on board service screen.

streborx

Most car batteries, including MB branded come from one of 3 major manufacturers. I've been buying Duralast Platinum batteries from Autozone. Replaced my 3 year old MB OE battery a year ago with one, and it's been fine. 3 year warranty / about $250 with core exchange.

Mmr1

11.2 is dead, or about 25% charge , that can damage your electronics on startup.
It’s like 12 years , junk it. Stop trying to squeeze it.

You could try an amp draw test when car is off. I was loosing charge and found my dashcam was locked on draining my battery .

but at that battery age just get a new battery before you get stuck somewhere

mcbridebr

Funny story time. I have been outside for the last 2 hours troubleshooting. Did a draw test, pulled fuses, etc. It was pulling .02 while off which I think is what i wanted to see. Enjoyed doing the test, first time for me. No parasitic draw, I think it is just a bad battery. But, funny part is I put it all back together and the left brake like would not turn off while key is out. Thinking I messed it up some how I was checking all kinds of things. I forgot these vehicles have parking left and parking right lights that you can control individually. The switch was flipped to the left light on. Thats what I get for trying to troubleshoot it at 11PM.

Mmr1

What kind of charger do you have , you do need one with an AGM cycle ,CTEK makes a charger every major brand puts their name on it , calls it their own, and doubles to 10x the price , that’s Rolls Royce. The charger has a , restore cycle , to attempt to desulfate a battery. They are cheap, about 60$ and good to have around. Yes MBs charger is a CTEK rebranded. When a battery gets below 12.2 it starts to sulfate , Sulfation destroys a battery in a few months. I always thought it was normal for boaters to replace their batteries every year until I learned this. The Cetek is also a Maintainer and comes with a quick connect plug you install on the battery, so hook up is a 5 second ritual.

streborx

Chargers and maintainers are accessory must-haves if you park your car for more than a week, or if you're doing any maintenance that brings the vehicle out of standby mode for a couple hours. A battery tester (under $100) is a good investment too. I'm ambivalent about small lithium jump starters -- I'd rather just buy a new battery preventatively every 3 years.

Silver Shadow

East Penn Manufacturing
Johnson Controls
Exide Technologies
These 3 companies make most of the car batteries in North America. Most battery brands are just labels of these three. Whichever battery you buy, it's possible to find the actual manufacturer with a little research.
Choose a label, buy a battery, happy motoring.

calder-cay

And then, stuff like this happens

Exide Technologies’ former EMEA and Asia-Pacific business now operates as a standalone company under new owners. On October 27, 2020, the battery manufacturer announced the ‘closing of the deal’, successfully concluding its separation from the Exide Technologies Holdings in the US and the transfer of its entire business to a group of long-term shareholders, under the US-based Energy Technologies Holdings LLC.

streborx

Johnson Controls divested its battery business a couple years ago and branded itself Clarios. Clarios makes Varta and Optima brands, as well as a long list of private label and OEM batteries, claiming that it owns 1/3 of the world market.

calder-cay

I found this at a webpage dated 2017, but we know how fast business ownership changes:

Most car batteries are made by Exide, Delphi, or Johnson Controls. Each manufacturer provides a variety of battery brands.

Delphi manufactures battery brands like ACDelco and EverStart, while Exide makes Champion, Exide, and Napa. Johnson Controls manufactures brands such as Duralast, Diehard, Kirkland, Motorcraft, and Interstate

https://www.zorestowing.com/blog/top...on-the-market/

andreigbs

My OE battery lasted 10 years. It got to the point where a trickle charger would limp it along but if you forgot to hook it up, it would be basically dead and no start within a couple days.

I got my new one from NAPA, for about $200 and comes with a 3-year warranty.

Can't beat local pick-up and easy exchange if needed.

John CC

If your battery is 12 years old it doesn't owe you anything. If you're having starting problems, replace it. An AGM battery at 12.2 volts is only about 60% charged. I can't explain your load test, but I wouldn't hesitate to change the battery.

If you want to do a test, put your volt meter on the battery and have someone try to start the car.

Odd Piggy

A few years ago I invested in a high end battery tester. It used high amperage dynamic load against variable low resistance to get the cranking and cold cranking amps. Then it used timed low amperage load against constant high resistance to get amp-hours capacity.

• Guess what? All that information is superfluous if the car won’t start. Just hook up a voltmeter like @John CC says and if the voltage drops to 10.8 volts while cranking, clean all the connections, + and - battery, ground lug, and every terminal all the way to the starter and test again. If it still drops to 10.8 V, replace the battery.
  
• My $$$$$ battery tester now sits on the bottom shelf of my work bench collecting dust with my timing lights.

John CC

Right on the battery posts. Not on the clamps or the jump points, or anywhere else.