[RCM1210]

Originally Posted by ronda

Great advise from villagetinker. My sister's car had this problem once. The trunk light was staying on. You can look for obvious things like that. Check your done lights, etc. If you can't tell if trunk light stays on, you could remove the bulbs and see if there is any improvement. Another idea, you could put you iphone video camera on and close it in the trunk.

Thank you for your help. Oh... the light(s) were the checks I performed. All looked good! Thank you again

[RCM1210]

Maybe I should hope it's the battery... Probably cheaper than diagnostic testing and then repair!

[RCM1210]

Originally Posted by oneclickplus

I didn't see anyone mention the alternator as a possible failure point. Connect your voltmeter to the battery with the engine running. You should see 14+ volts. Less than that and you have a bad alternator.

Thank you for your suggestion.... My intention is to perform that very test sometime today! Thanks!

[RCM1210]

Originally Posted by retiredguy123

I am on my third AGM battery in 7 years, with 60K miles. They cost about $300. My vehicle is always parked in the garage.

Oh my... you make me feel "kinda" lucky

[RCM1210]

Originally Posted by Accidental1

I had a similar problem with my 2008 Acura TL. It wouldn’t start after sitting for two days, but if I charged the battery and disconnected it for two days, then reconnect, it’d crank right up. Sumter Tire in Wildwood diagnosed the parasitic drain for me (related to Bluetooth module) and we decided to just disconnect it.

I'm just learning about the parasitic drain. My intention is to attempt this testing today. Thanks for your info

[Cliff Fr]

If you end up determining that the battery is bad you might want to invest in a battery tender. It's a trickle charger that keeps the battery charged for you when it's parked in the garage. All those short trips keep the battery below a full charge which wears it down faster. IMO your just as well off buying a 36 month battery from Walmart

[Rocksnap]

For any vehicle that sits for long periods, May I suggest a trickle charger battery tender?

[Sgt Ed]

Originally Posted by RCM1210

I'm in need of advice and/or a dependable auto mechanic for a 2015 Benz with 81000 miles that we've owned for 7+ years . My expensive 3 1/2 year old Duracell AGM battery goes dead about a day and a half after charging and starting a few times in the garage. I'm not sure if there is an electrical drain or bad battery. I was able to check all the fuses, except for 4-5 (under the hood) with a multimeter, which I couldn't reach the first try.

I've always worked on my own vehicles, but I'm no electronic/electrical guy. I only found out yesterday how to use my multimeter just enough... to check the fuses, lol. Have you ever heard the saying, " I drive it till the wheels fall off"? Well that's me!

Any suggestions would be very much appreciated.

And thanking you in advance.

I've just been down this road with my Porsche, after dealer telling me I needed to replace the battery, some $400 buks and get the car on "Their" computer to set the electronic regulator. Utter B/S, I'm a retired mechanic, so I take to my friend who has a high line repair sho to see about a ghost short. It turns out I was keeping the key too close to the parked car. It would not let the computer and Lord knows what else go to sleep. If the key was in my pocket ,every time I walk past the car it would wake up. Solution, keep the key in bed room till I want to drive it. System has worked now for 4 months. Good luck.

[airstreamingypsy]

The battery in my Mercedes is under the front seat, so Auto Zone won't check it. To answer your original question I would take it to All German Motorworks in Leesburg off 44. I bring mine there and they are lovely..... Maserati, Bentley, BMW, Porsche, Audi, Mini, Mercedes, Service Repair

[LeftyMike]

I suggest that you join the Mercedes Enthusiasts Club, to get access to our members only list of recommended vendors: mbenzclub.com

If you put in the battery, you probably did not reset the battery on the car's computer system. Thus, the car has been overcharging the battery since new. A 3.5 year life is great under those conditions. If the computer was reset when newly installed battery, Have the battery tested outside of the car to determine if it is a short in the wiring or a failed battery.

Originally Posted by RCM1210

I'm in need of advice and/or a dependable auto mechanic for a 2015 Benz with 81000 miles that we've owned for 7+ years . My expensive 3 1/2 year old Duracell AGM battery goes dead about a day and a half after charging and starting a few times in the garage. I'm not sure if there is an electrical drain or bad battery. I was able to check all the fuses, except for 4-5 (under the hood) with a multimeter, which I couldn't reach the first try.

I've always worked on my own vehicles, but I'm no electronic/electrical guy. I only found out yesterday how to use my multimeter just enough... to check the fuses, lol. Have you ever heard the saying, " I drive it till the wheels fall off"? Well that's me!

Any suggestions would be very much appreciated.

And thanking you in advance.

[bark4me]

All cars have something that will drain your battery. If you don't drive it frequently get a trickle charger and keep it on that when not in use. So the issue is your battery is dead and will not hold a charge

[CarlR33]

Check for the obvious first then I would yank the battery or drive it to Advance or other auto place to have it checked. One thing no one asked was have you made any changes to the cars electrical recently like add an accessory or something as simple as a phone charger?

[RCM1210]

Originally Posted by biker1

It may have died a premature death. My automotive AGM batteries have lasted between 6 and 9 years in southern GA and FL. Perhaps there is still some warranty remaining on it.

No warranty here. Ran out the later part of April this year. what luck huh?

[RCM1210]

Originally Posted by Sgt Ed

I've just been down this road with my Porsche, after dealer telling me I needed to replace the battery, some $400 buks and get the car on "Their" computer to set the electronic regulator. Utter B/S, I'm a retired mechanic, so I take to my friend who has a high line repair sho to see about a ghost short. It turns out I was keeping the key too close to the parked car. It would not let the computer and Lord knows what else go to sleep. If the key was in my pocket ,every time I walk past the car it would wake up. Solution, keep the key in bed room till I want to drive it. System has worked now for 4 months. Good luck.

I would have never thought about that. I do keep my keys close to the car when I'm messing in the garage. Thanks for that "crazy sounding" advice, but I do understand!! I'll surely try to do better!

[RCM1210]

Originally Posted by Rocksnap

For any vehicle that sits for long periods, May I suggest a trickle charger battery tender?

I do have one for the cart. Good suggestion. Thanks.