W203fanatic

Yes, chassis I searched only got 2 results searching “dead battery” in the W166 section.

So this hasn’t happened yet but I am just wondering how can you get inside the car if the main battery dies due to being left sitting too long?

threeMBs

The same way as ANY Mercedes - use your little mechanical key (the one that locks the glove compartment) from key fob.

W203fanatic

So there is a physical key in the key fob? Also a physical key hole in the door handle?

chassis

Yes. Search for it in your digital owner’s manual.

Pages 74-81

https://www.mbusa.com/content/dam/mb...V_Operator.pdf

W203fanatic

Ahh perfect. Makes sense now.

I was worried for a bit because some cars like the E46 BMW there is no key to get inside the trunk which has the battery. Only way is to destroy a brake light and fish for the trunk release. I was worried Mercedes had no actual keyhole for the drivers door which gives access to the hood release. Smart design.

Thanks for the replies.

Etienne Lau

@W203fanatic Your vehicle will display other 12V symptoms long before you get to the stage where you cannot open your vehicle door.

skippk

What other symptoms?

Etienne Lau

Car won't start is the first one. You'll have enough power to open doors, turn on radio, etc...It just won't start. Other symptoms include random flashing of lights in the dash etc....If you battery is sooooo dead you can't unlock the door, then you've let the battery drain down too much.

YankTar

Which can happen if it sits too long--like months or more during the lockdown.

Etienne Lau

That's why I bought myself a solar panel, and connected the panel to the battery. And it keeps the battery topped up for months at a time......There just no excuse in my book to have a dead car battery.

YankTar

I gotta tell you, even with a Battery Tender followed by a Duracell smart battery charger, I had my S500 battery go TOTALLY flat repeatedly. So you can't be so sure there's "no excuse".

Etienne Lau

Does you S500 use an AGM Battery? If yes, did Battery Tender and Duracell smart battery charger have settings for AGM battery? IF NOT then yah, any AGM battery will die. I ended up disconnecting my Solar Panel for this very reason, and resigned my self to driving the vehicle once every 2 weeks instead of letting it sit there for months at a time.

YankTar

No, it's not AGM. But I hope that driving it a minimum of every other day will keep it from going flat. I've been fighting a parasitic battery drain in our 2003 S500 4matic for several years now.
But, our 17 year old just got his license and I want him to drive this car rather than our Traverse, because it's old, it's book value is low, and it STILL drives like a dream!

Etienne Lau

YankTar, I hear you, that's why my son is driving our 2001 Subaru Forester, about 5 miles each way to college and work to keep that battery from going flat. Bummer about your S500 parasitic loss. You try hooking up an Ammeter on the battery and pull fuses?

YankTar

Oh, hell yeah! Then had it to 2 specialist shops and NEITHER could find it! Talk to a stealership and you can't get a straight answer about what 2 hours of hunting for leaks with THEIR computer would cost!'

tsair

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