I was referring to the "Memory saver" part of the site. It's supply 12volts through the cigerette lighter before connecting the car battery. Some of these memory savers have a surge protector build into them. My thought would be:
Before connecting the car battery you plug the memory saver into the ciferette lighter socket (with the surge protector built in) after you have the system charged to 12 volts then you attach the battery cables. Should be no, or little potential difference so there should be no arc and no spike.

 

https://www.ebay.com/itm/Draper-12V-...7/302015700030

Memory save with surge protector

 

And if the battery is over 48 months old, replace it.

 

using a memory saver
when disconnecting the battery there is the chance of spikes in voltage damaging the SKREEM and erasing programs.
i have read that using a memory saver you can avoid this.
i would like to ask the experts the details on how to do it. what parts, where to get them, where to connect it, everything.
thank you.
so far i have learned that you have to connect a memory saver to a source such as the cigarette lighter, but on some cars (like the xf) it is not functional until the engine is running or the circuit is closed (lights on the dash on) so it has to be connected to the OBDII connector.
perhaps using something like this? https://www.ebay.ca/itm/OBDII-Car-EC...4AAOSwbRRcw8zN
in this pic it shows a pack where they are connected .
edit: i managed to read the name and found several. now the question is if there is any experience using it (or similar). thanks.
this is 1: https://www.wish.com/product/5680d8a...xoCZ68QAvD_BwE

 

Let’s think about that, the battery is disconnected, the power supply is plugged into the lighter socket And we have two wires with alligator clips on them. Where do we attach them, I think the ads tell us.

But as pointed out it previously it will not work on the Crossfire, so that Power supplier is NFG for us unless the car has the pizzaguy mod.

 

I can never figure out why people come up with hair brained electrical ideas when it is clear with everything written in this forum that these cars are real picky about all things electrical. Keep a good battery in your car, never give or get a jump, don't use a trickle charger always remove the negative battery terminal when doing ANYTHING electrical. After that you are asking for trouble. I put our crossfire up on stands about a month ago. Changed the oil, brought it up to temperature, shut it off and covered it up. I intend to start it on the stands once a month and run it up to temperature, about 15 minutes. Did that yesterday. Started great, ran great and now covered for another month. If your car won't hold a charge for a month you have an electrical issue of some kind that a trickle charger is not the solution to. There is no need to remove or disconnect the battery if you are just parking your car. There is no advantage to you, it's just a "feel good" procedure with no basis. Just sayin'.

 

Hi Johnny, I don't know how my battery issue transformed into whether to disconnect the battery or keep the battery connected. Since the Crossfire seems to be very voltage sensitive, I agree with you and onehundred80 and would keep the battery connected and charged. That is what I have been doing for the past 1 1/2 years with no negative results. It just so happens that my battery finally failed, I replaced it, and my Crossfire seems very happy with the new battery. Since I only drive the Crossfire on very nice days in the winter months I will start the car every couple of weeks in the winter and let the engine warm to operating temperature.

 

I disconnect the battery when I put it on a battery tender for a few days as I really do not trust anything like a battery charger attached to the car, who knows what might go wrong.

 

I disconnect the battery when I put it on a battery tender for a few days as I really do not trust anything like a battery charger attached to the car, who knows what might go wrong.
I like my batteries rare, not well done.

 

Hey Phil, I have a memory saver that uses a 9v battery. I've used it on one of my collection. It worked perfectly, which amazed me to be honest. It was cheap too.
I know that the crossfire doesn't have an active circuit to the cigar(ette) lighter unless the key is in the run position. The remedy to this is to hack into one of the circuits that is always alive. That would be the parking lights for me. You can create any type of connection you want after using the type of wire tap(s) that are readily available. I don't know of any danger to the skreem module and from reading exhaustively, I think everybody is guessing. Please, no offense to anyone on this. I don't pretend to be an expert but I have been preserving my fuel trims and keeping batteries charged while cars are in storage for decades. Anyway, it is apparent the mercedes electrical system has some gremlins. I personally am not worried that tapping into my parking lights via a wire tap is going to jeopardize other components. I may learn the hard way but that won't be something new.. .

 

thank you for your message polite, positive and to the point.
i have 2 questions:
1-which saver you use? details on product part #, name, and source if you remember will be highly appreciated;
2-what if i plug it into the socket where the code reader fits? i think it is active even without the key plugged.
i was thinking on something like this: https://www.aliexpress.com/item/3297...E&gclsrc=aw.ds
thanks again for your help.
i am asking you directly this, but if somebody else has some input (polite, to the point, and positive) is welcome.

 

Aha, found it down in the basement hoarding room.
NOW, let me find you the cigarette socket accessory (I have one). These are sold ubiquitously as well.


Bought 10 years ago, probably online. Verified that it works..

 

How about this.

 

Okay, here's a bit more. I would find the always hot +12v wire that is attached to the light switch. Tap into into it and use one of the following receptacles with the above memory saver. I would simply cut the two wires going into the aftermarket accessory socket. Attach the tapped wire from the light switch appropriately and make myself a ground to the frame in the dash and attach it to the other wire.

Probably cleaner and better methods but I've got a lot to do elsewhere..

 

Yeah, way better! Thanks..

 

.


I hear the JAWS theme. Seriously, I had my car disconnected for quite a while, nothing connected to 'keep' a memory. The ONLY thing I had to do was reinitialize the 'Do not beep the seatbelt warning buzzer' when I move the car on my property. All the radio stations were there, no problems with relearning the ECU (ran fine no stumbles) and I didn't notice anything of note that would suggest I needed anything to 'keep' a memory. Just saying!


.

 

yeah. thats the closest/lowest price i have seen. thanks a lot!

 

No one abuses cars like I do. I have tried tenders, but they scared the hell out of me. So I try to start them and run them through the winter. Drive them around town when the roads are clean. But, from time to time the batteries get low and I put a charger on them to bring them back up. I don’t jump start them at all. I haven’t had any problems doing this. I am not sure what causes the dreaded skreem problems, I just hope it doesn’t happen to me. I haven’t had the sticky key issue yet, but the roadster is getting touchy. I never hang anything on the keys. Just the fob. I haven’t ever lost any settings. Even my dashdaq keeps working. Just keep good voltage in the batteries. And keep up on your reading in the search areas. A lot of electrical gremlins can happen. If you have ever seen a totaled XF with the dash out, you will see thousands of feet of wiring....lol