Trickle Charger
Super Member
Joined: May 2009
Posts: 810
Likes: 182
From: Laguna Niguel
'94 SL600,'05 SL600,'06 S65,'07 E63,'14 E63S,'09SL600 all sold, ‘15 S65,‘18 E63S,'17 SL65, '17S65Cab
I bought a CTEK for my 2009 SL600. Used it a few times then just replaced both batteries. The CTEK worked fine. With the new batteries I can now leave the 2009 SL sit unused for close to a month, it starts right up, all accessories on line.
As for the W222, I have never had a need for a trickle charger and my 2015 S65 frequently sits 3 weeks between uses with never an issue. I imagine the CTEK would work if needed but there is not a convenient connection point on the S. The only approved location is inconvenient under the hood.
What I found more useful was a Schumacher 100A speed charger/starter. It was easier to just use that on the SL when the battery dropped below 25% charge before I replaced the batteries. Just took 5 minutes and the car would start w/o the charger. It would start immediately with it. Again, in 3 years I have never had a low battery on the S despite letting it sit unused for close to a month.
As for the W222, I have never had a need for a trickle charger and my 2015 S65 frequently sits 3 weeks between uses with never an issue. I imagine the CTEK would work if needed but there is not a convenient connection point on the S. The only approved location is inconvenient under the hood.
What I found more useful was a Schumacher 100A speed charger/starter. It was easier to just use that on the SL when the battery dropped below 25% charge before I replaced the batteries. Just took 5 minutes and the car would start w/o the charger. It would start immediately with it. Again, in 3 years I have never had a low battery on the S despite letting it sit unused for close to a month.
