Hi Folks stretch here new member as of today already looking for some help. recently treated my wife to an SLK R172 250 CDI ( we love it )

[stretch5]

Wondering if anyone can advise / help I'm looking to put a trickle charge on the main battery over the winter months and wanted to know firstly is the battery in the boot on the passenger side and if so how difficult is it to access and has anyone got pics / video or little tutorial detailing what needs to be removed - thanks in advance folks

 

[markjay]

Welcome.

Not sure where the main battery is on your car, but all MB cars have a positive charging point, i.e. there's no need to get to the actual battery.

Look under the bonnet for a red plastic cover with the (+) sign on it.

I am guessing it's the red bit in this photo:

The (-) connection usually goes to one of the bolts at the top of the front suspension strut. I am guessing this would be the long protruding stud on top of the strut at the left-hand side of the photo.

 

[markjay]

See also:

Battery location UK Right Hand Drive 2012 SLK 250 CDI R172 please. | Parts, Maintenance & Servicing

Greetings from sunny old Leicestershire...not!! I recently purchased a 2012 SLK 250 AMG Sport R172. I chopped my STI Spec-D Impreza in for it, that I had had for 8 years and 1 day !! I do find the Merc much nicer in a lot of ways to own and drive, but it's infuriating in others, as I had the...

forums.mbclub.co.uk

 

[Chrishazle]

Battery on my R171 is under the bonnet, passenger side, under the drain funnel for the bonnet vent. Drain funnel releases with 3 x 1/4 turn plastic finger screws, one at the front and 2 at the rear, then just lifts out. Being able to lift the bonnet high really helps. I connect my trickle charger direct to the battery, have to leave the bonnet up as there's no rubber seals on the bonnet to protect the wires, but you can still lock and alarm the car (and she's in her locked garage anyway) so I'm not bothered by that, and you quickly get the hang of releasing and re-installing the drain funnel!

 

[Deleted member 126251]

Welcome.

Not sure where the main battery is on your car, but all MB cars have a positive charging point, i.e. there's no need to get to the actual battery.

Look under the bonnet for a red plastic cover with the (+) sign on it.

I am guessing it's the red bit in this photo:

The (-) connection usually goes to one of the bolts at the top of the front suspension strut. I am guessing this would be the long protruding stud on top of the strut at the left-hand side of the photo.

Yes and in my owners manual, the jump start points are the recommended way to charge the batteries....

 

[jimbg]

Ctek are probably the best trickle chargers

 

[Chrishazle]

The other option is Lidl's £15 thing - which is what happens to be connected to my SLK this year, after years of using something else (much older, pre-dates CTEK, and still works fine!) for the past 20 years. Seems to work OK so far, reviews either say it's fine or it falls over within 3 years, whereas CTEK reviews are invariably positive, but you'll pay £50+ for a CTEK! For an MB, I've only had one I can put on a trickle charger since Nov 2019, but in the past with my 968's I always connected direct to the battery as they did not have under bonnet alternatives. I can't leave a conditioner on the S204 as it lives on the driveway, but it's very little additional problem to connect direct to the battery on the SLK so that's what I do.

 

[Smart320]

I always use the under bonnet charging points to connect my CTEK on my SLK

 

[SmartAmg]

Welcome..

 

[kcsun]

Use the under bonnet charging points
C-Tek are great
Lidl is good with one problem, in the event of a power cut, it does not automatically restart, the C-Tek does

kc

 

[Larkone]

Not all MBs have a charging point under the bonnet - my CLS certainly does not.

 

[flowrider]

I've had 2 trickle chargers from Lidl, the first one failed as soon as i turned it on for the first time and the second one failed when i turned it on for the second time. I guess I was unlucky. My Cteks (MXS5.0 & MXS10) have both been regularly used over the past 4 years without any issues.

 

[markjay]

Not all MBs have a charging point under the bonnet - my CLS certainly does not.

You may well be right - I meant recent cars - the W218 definitely has one, though your W219 might not.

 

[whitenemesis]

Just so much easier to permanently wire directly to the battery (or battery positive and body negative if fitted with BCM) and have the convenience connector accessible for quick connect/disconnect.

 

[Smart320]

The CTEK also comes with a connecting plug and cable that can be permanently wired up to the battery terminals so you can site the connection plug in a convenient place in the car or boot, I used it for my ML and for my wife's Rav