Found this Memory Saver gadget.

Seems to offer the opportunity to save a lot of time when doing electrical work.

They Quote :-

"It is always safer to disconnect your battery when working on major components. But today's audio equipment needs a constant current to maintain your radio station presets and other settings--even your radio security system, car alarm memory and clock. Here is a simple solution. Our memory saver plugs into your lighter socket and has enough power to retain these important settings so that you do not have to reprogram all of your components. 9V Battery included. Comes with optional adapter for AA batteries. "

Might also work on some models that loose control settings when battery off for some time.

Memory Saver Link

Mike Stone

It might work for a Chevrolet (although I doubt it). It absolutely won't work on that MB you have in your picture or any other that I know of.

TWO major problems. First the cigarette lighter is unpowered with the ignition key OFF. If you turn it on the power that will be used (that the lighter socket would need to support to keep voltage up) would drain a 9v battery in milliseconds.

The second problem is that a modern car such as yours (and probably new Chevrolets) will wake-up their control units with the door opening. The combined load will knock down a 9v instantly with the computers awake, a worse case senario.

If you seriously want to do what you these devices intend, I would suggest a motor cycle battery with a pair of large aligator clips attached to leads. This of course does not help if the reason you are doing this is because the procedures say to disconnect battery (as in SRS repairs).

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

just run your own secondary memory wire to the radio. then keep it connected to the battery and disconnect everything else that doesn't need constant power.

They sell a new battery terminal for your positive connection that will retain memory but allow the battery to be disconnected with a simple twist of a knob.

Alon

__________________
'92 300CE - Sold
2004 C240 - 744 - C7 Wheels - Android Radio
2002 C320 - 816 - Sport Wagon

The presets (in a Mercedes anyway) will stay in the memory for MONTHS (forever?) without power!

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)

but not in an aftermarket stereo... though I suspect newer ones may just hold presets...

A neat idea, but probably not worth it when it comes to my benz, I prefer something a little better, hence the reason I would stay away formt he cigarette lighter jump starter, do I want that kind of juice goign through my fuse box? nope.

I would rather use a jumper battery pack that clips onto the battery, or a good ol jump start like usual.

Alon

__________________
'92 300CE - Sold
2004 C240 - 744 - C7 Wheels - Android Radio
2002 C320 - 816 - Sport Wagon