petezelk

Just got back into town after a few months and looks like battery is dead. Tried boosting it with a friends H2 hummer and also separately with a DBPOWER 800A portable car jump starter.

No luck. Display lights up and I just hear a loud click as the engine tries to turn over.

Should I trickle charge the battery or replace? It was replaced 3 years ago at MB dealer (OEM part)

New OEM battery is $280 all-in
I've seen some aftermarket ones around $200 minus core.

You guys got any recommendations over the OEM?

Also, is it easy to replace battery myself, I have all the tools I think.

Thanks!

Dr.Speedfellow

I will leave it up to you to figure out charge vs replace as it should become obvious very quickly if it will or won't hold a charge.

I swapped to an odyssey 49-950 battery. I have found odyssey to be long lasting and of high quality with no issues. They used to be considered expensive but I got mine for a similar price to what you quoted in your post.
Be aware that odyssey batteries require a certain spec for proper trickle charging maintenance if that is something you will be doing. Not all trickle chargers meet odyssey specs and the wrong one can drastically reduce life of the odyssey battery. Their website and customer service are very specific about which models they approve.

swapping the battery is very simple and requires only common sense.

roadkillrob

Is it the original battery, if it is over 5 years old (date is on the top of most batteries) then it is time to replace and easy to replace, I just do OEM unless there is a reason not to typically and if it has lasted 5+ years then you got a good life out of it.

Cwagon

If you had it replaced 3 years ago it should be fine to just charge up
Like roadkillrob said check the age of the battery as the dealer may have used an old battery.
Date is either stamped into the positive post or on the sticker.
My OEM battery is coming up to 8 years old so in normal use yours should last 5years minimum.
You should get your electricals checked to see if you have something draining the battery while sitting for long periods.

roadkillrob

Assuming when you say got back into town after a few months the car sat for several months with no battery maintaining device. If that is the case, put it on a good charger and see if you can get it to charge back up and you may be ok, but if it sat for 2 months I would expect a dead battery on these cars and would be best to have it on a battery tender or something for extended periods.

DRBC43AMG

Mine has a 12' stamp on the + terminal and still going strong. I do keep a trickle charger connected if the vehicle is not used over a couple of days. No signs of imminent death, so should be good at least fit the upcoming summer months. I'll see in November if it gives signs of upcoming death or not

petezelk

There is a blue sticker that says 5/18 and I had it changed in June 2018 at the dealer.
I can bug the dealer service guy and ask him if they can replace it, but I doubt there is a 3yr warranty on these.

Thoughts on the AAA batteries?
They quoted me $228 for a type 49AGM-C battery, plus a decent sounding warranty.

"All AAA batteries comes with a 6-year warranty. The first three years include a free replacement if the battery test fails. For the remaining three years, the warranty provides a battery purchase at a prorated cost."

petezelk

***AAA meaning the batteries that AAA Roadside provides***

petezelk

Got it done through AAA, no issues with their battery so far, starts like OE.

What should I do if I'm storing the car for a couple months and don't want the battery to die?
I don't have access to a wall plug where the car will be stored.

Thanks!

DRBC43AMG

I would take the battery out of the vehicle and store it with a trickle charger on it. Manually lock the doors after removing the battery, or leave it unlocked if it's going to be in a safe place

petezelk

Thanks guys!

Don't have a trickle charger, could you please recommend one for me?

PS - how can I use my physical key to manually open the trunk when there is no power to the car?

DRBC43AMG

I use Ctek units for both my AMGs. They work great. https://www.ctek.com

Regarding the key for the trunk I have no idea as I've never tried.

Music City Benz

If the battery is deep discharged, it might not come back from the dead. Lead acid batteries don't like anything under 10.7 Volts without taking damage. A trickle charger is a good idea, if you don't drive the car a lot. All the electronics put a small, but constant load on the battery. Go for the battery with the best replacement warranty. I had supposed quality ones fail within a couple of months. 3 year replacement warranty should be a minimum.

petezelk

Yeah, AAA read my battery as 8.4V so it was likely close to fully dead after a few months.

Thanks for the ctek link, lots of products to learn about.

Looks like there is a place to put the key on the left side of the trunk, underneath where you grab the latch

DRBC43AMG

Next time I pop the trunk I'll open my eyes and look for the key opener

parravan

Hi
My battery is dead after in storage.
I don't have an outlet available to trickle charge.
I can get a replacement AGM for it.
Is there any reset that has to be done? IE: Re Mercedes ?
Is swapping it out enough with the old battery ?

For the future, I was thinking of getting a second 12 v battery or boosting station and plug it in to the cigarette lighter to trickle.
Then take it away every month to charge it and put it back to keep the main battery charged.

eightysixtuned

just put a manual kill switch and when you park it switch the battery off.

parravan

Hi 86tuned
I guess that means no need to worry about having to reset anything after switched back on?

I'm not too worried about losing presets in radio or navigation..

NZ-Merc

I would also recommend Ctek battery charger I only connect mine if it is sitting for more than 1 month just to charge it back up. I know most people just connect them up once they finished driving and just leave them to connected until next drive.

parravan

Hi
No outlet available.
I assume battery charger requires 120v outlet?
How bout a second sealed 12V battery plugged into cigarette lighter socket.
Take it out to charge every month.?Should provide longer time for the baseline draw.
Just put it in the trunk when going to drive the car.

eightysixtuned

i don't think presets are wiped. only your time and date will be off, but once you connect to a GPS satellite it will sync back up date and time if that is what you've configured within your settings.

as long as you are able to close your trunk, you'll be fine. on my E63 i am not able to due to it being electronically controlled. a friend of mine recommended a remote or bluetooth battery kill switch for my situation, but i haven't looked into it.

Diabolis

You will also lose the seat, mirror and steering wheel preset / memory positions. Mine is still on the original battery (so 10+ years old in a 2013 car) and it is as good as new, but I do take the car out for a nice long drive at least once a week even during winter though. The longest I've ever let it sit was for three and a half weeks and it fired right up.

If you need to do this frequently, installing a kill switch is probably the most convenient solution based on the location of the battery in the trunk, but those things are not necessarily without issues as the actual switch contact surface area is relatively small and introduces some resistance. I was chasing electrical gremlins on another car for months (it would sputter and die when everything was hot and you completely lifted off approaching a traffic light for example) before narrowing it down to the kill witch I had put in. If I now need to disconnect the battery for any reason, I just disconnect the ground terminal and with no drain it will easily hold a charge for 6+ months.