2012 merc amg

I've never tried sleep mode when leaving the car, normally I just put the windows down a few inches so the int has some air and leave the car unlocked and hook up the battery maintainer. I worry about locking the car and having the alarm on in that it could go off for some reason while I'm gone like in the middle of the night or something and wake up the neighborhood. I've never really had a problem doing it this way although I'm sure the battery maintainer has to work a little more than if I put the car in sleep mode and locked it up.

Rick2019

Is the starter battery a Lead/Acid Battery or Lithium?

Mercedes offers two types of trickle chargers

Gazwould

Pretty lights....





You want a display with some useful factual information .





Oh and one C-Neck buys three of these , lol .

Elvisfan0108

The first charger specifically says for either lead acid or lithium.

CarFan1

I've been using a trickle charger since 2017 when I got tired of replacing batteries in the Porsche. I've never used sleep mode and now the battery is like new and I've recently started using it on the Mercedes last year. I haven't figured out yet a set up where I can keep the Mercedes on a plug and play. In the Porsche, I'm able to keep the charger cables connected year round and then simply use the connector for charging which I do after most drives. For the Mercedes there isn't as much space with the hood closed to keep the charger cables connected necessitating a tedious process to hook up the charger each time I want to charge.

slk55er

I'd like to mention that some vehicles (like my GTS) have 12volt Li batteries and these require a special Ctek charger specifically for Li batteries (which I have) to avoid overheating the battery. It looks like there is a Ctek charger that will handle both types.

JTK44

I think there is little to no chance and little has left town that a CTEK charger, or for that matter any other trickle charger will overheat the 12 volt Li batteries.

The amount of charge these trickle chargers put out, it can take up to 24 hours to fully charge, is so small that there is no way they will ever damage any battery including a Li battery.

If you go into any Mercedes dealer you will see these massive chargers charging the showroom models on the showroom floor. That charger is a so many times more powerful than any trickle charger. There is no adverse effect on the 12 volt battery.

Just my $.02.

slk55er

Well, perhaps. At the time I had my GTS (with a Li 12v), I did extensive research and concluded that I better buy the CTEC specifically designed for a Li. Maybe you could research it also. As an aside, I wonder why MB did not use a 12v Li in our 48v 53 M256 engines -- perhaps over concern that unknowing owners would use an incorrect charger rather than one for a Li battery?

A quick Google search says: