DaveFr

I'm going on vacation for a month soon. I usually disconnect the battery on my cars when they will not be used for that amount of time. Is disconnecting the battery the preferred procedure for E class cars?

I found a thread on this forum from about a year ago discussing this but opinions about the best procedure varied. Some posters thought a battery in good condition should be able to last a month while others recommended disconnecting the battery. A third option would be to use a product such as Deltran's Battery Tender to keep the battery charged. Based on everyone's past experiences what's the consensus on the best approach?

If disconnecting the battery is the best way to go, is it sufficient just to disconnect the negative terminal as one poster suggested or should both terminals be disconnected as stated in the manual?

Any help, suggestions, comments would be greatly appreciated. Thanks

Randy B

I believe you will have to get some things reset by the dealer if you do that , plus you have two batteries in the car that you would have to disconnect. Probably better to call the dealer and see what they say. Quick question which will not take much of their time.

mbprince

I would buy and use a small battery maintenance device and keep the batteries connected (the E series has 2). I have many of these little wonders, they have a chip in them that tells them when the battery is charged and they go into an idle mode. I have several vehicles that are only driven once or twice a year and they really do the job!!

rusnakmb

Hi,

The first guy it right.

When disconnect the battery, it will reset the setting. You might have to back to dealership to setup the car again once battery disconnect.

Example: the sunroof need the new setting and few other small thing. The car still can be operate

Long Islander

I have one sold by Porsche dealers that just plugs into the cigaretter lighter. Much better to keep your battery charged than just disconnected -- and easier too.

E55AMG99

Disconnecting batteries is not the best thing because many custom settings are lost. Also, many new MB like the E and SL have 2 batteries. You will need to drop both of them.

Buy an automatic battery maintainer. Make sure it is a fully automatic "maintainer" and not just a charger. Make sure it can stay connected to the battery for extended periods. Unless the cigarette lighter is hot when the key is off, connect it directly to the battery or charging post if provided. You will need to make sure that both batteries are being maintained. My guess is that when the car is off, the batteries are NOT connected together since they will self-discharge faster that way.

I have a variety of maintainers that I use for different vehicles. The solar powered models are OK for small batteries like my snomobiles and SeaDoos but not quite up to the task of maintaining a car or tractor battery when it is still connected to the minor current drain of the vehicle.

Long Islander

Good point about the need for the cigarette lighter to staying on when the car is turned off. I only use mine on my Porsche, which apparently does stay on when the car is turned off.

Otto

Dave,

If your batteries are in a good shape, there is no problem for 30 day vacation. (but you are not sure about this, aren't you?)

To avoid unnecessary jumpstart or a dealer trip, I suggest you install a trickle charger to your main battery (in the trunk), then enjoy your vacation. The charger is smart enough to stop charging it automatically when it is done. (I used Deltran -- part number 022-0139 because w211 batteries cannot be charged from the cigarette connector which is the way my bimmer charger so I have to have two different chargers -- good thing for own 2 chargers is I can charge my two cars at the same time or I can have looooong vacation without worrying about car batteries.)

I proved 20 day vacation is ok for my car without hooking up charger (fully charged it before I went vacation.) but a trickle charger provides me better lights, better sound quality, heated seats and wheel, etc. services when I need them.

Otto

E55AMG99

Excellent choice! Probably the best maintainer on the market.

FJPM

I left my E500 idle for one month during this summer.

It started without any problem.

DaveFr

Thanks for all the replies. Since the battery in my car is a year old, I'm not going to take a chance that it can survive for a month while I'm on vacation. I'm going to buy a Battery Tender and use it to keep the battery charged.

BEC

I have left my E500 for two long trips, a business trip and vacation last summer that spanned three weeks. The car started with no problems.

Then, I left on 22 Dec for another combined business trip and vacation, returned on 17 January evening, and the car started right up. During this time, the car was left in an unheated garage, which was probably between 30-40 F.