Dead battery in winter, and how to open trunk with dead battery?
 

96 SL500, I have been using my truck for the past week and have not started up the SL. Well this morning it would not start with a VERY dead battery. Is it normal for a battery to die in a week in very cold weather if not started? This battery was new a year ago and I have never had any problems with it.

Also is there any precautions I need to take jumping the battery? Any relays or sensors I might damage?

And how do I open the trunk with the battery dead? I can put the key in and turn the lock, but when I push in the trunk does not budge. It could be frozen though, I am assuming I should be able to open the trunk with the key even with no battery power.

Thanks much.

Use a jumper cable to a good battery. Connect the positive cable first and then the negative one. Even if the battery is located in the trunk, there is a positive post in the engine compartment for this purpose. You should then be able to open the trunk.

You should be able to unlock trunk/cabin with key...
 

..even if battery goes dead. I would hesitate to suggest a jump start though with all the sensitive and expensive-to-repair electronics in the SL500. I have disconnected battery and used a charger to bring it back to life. In a pinch or on the road, do consult manual if jumpstarting is the only option. However in the confines of your garage/driveway, err on the side of caution and use a trickle charger.

97 SL500 sprt pkg 1
triple blk
27k miles

A week sounds kind od quick for the batt to go dead. Particularly if it was relatively new.

Do you have an active alarm system, my brothers Vette had that problem, but it usually took 2 or 3 weeks in storage.

Get a Battery buddy or what ever that will keep it trickle charged, I use one in storage all the time.

Thanx guys, it is worse now, even one day without starting will result in a dead battery. I just bought a new one, hopefully it is just the battery itself.

I lived in Mass for a few years and I used a simple 'battery Buddy' and it worked real well. If a batt is low and freezes it can (and most likely will) warp the plates inside causing them to contact each other thus shorting out some of the cells. This will cause the battery to fail in keeping a charge. I saw in the Want AD magazine a 1996 500SL that had 10K miles for sale because it was stored for many years and someone tried to jump start it causing significant damage to the electrical system, including the electric speedometer. Therefore when it was sold the reg had to suggest "milage unknown" This car had the original tires and the wind screen still had the plastic wrap on it in the trunk..... LIKE NEW CAR $15K... Salvage title!!!
In short, Don't jump start the car!! $100 dollars for a good batt... Thousands for a jump start.

[QUOTE=Marc-1]I lived in Mass for a few years and I used a simple 'battery Buddy' and it worked real well. If a batt is low and freezes it can (and most likely will) warp the plates inside causing them to contact each other thus shorting out some of the cells. This will cause the battery to fail in keeping a charge. I saw in the Want AD magazine a 1996 500SL that had 10K miles for sale because it was stored for many years and someone tried to jump start it causing significant damage to the electrical system, including the electric speedometer. Therefore when it was sold the reg had to suggest "milage unknown" This car had the original tires and the wind screen still had the plastic wrap on it in the trunk..... LIKE NEW CAR $15K... Salvage title!!!
In short, Don't jump start the car!! $100 dollars for a good batt... Thousands for a jump start.
Oh, while I'm here.. Use to live in Mass.. Just moved to Fl and I had the top down on JAN 1st :)))) 78 degrees, sunny, awsome, and... well, sorry for gloating Spine Doc, just couldn't resist :sun_smile

I had road side service come out to my place to jump my car when my battery died. I was like 4 miles from a benz dealer so they sent a mechanic with a new battery. I told him I did not want to jump the car because of the stories of people blowing electronics when jumping a car. He said that he has jumped 100's of SL's and it has never happened to him. He said if you don't cross the cables your fine. Anyway.... just put a new battery in an enjoy.