SL/R231: Battery Tender for 2017 450 Storage
Thread Starter
Senior Member
Joined: Feb 2020
Posts: 278
Likes: 118
2017 SL450, 2017 Ford Expedition, 2007 CLK 550, 2019 Buick Enclave
Battery Tender for 2017 450 Storage
First off, yes I am a little gun shy about this car. It intimidates me a little so far, but I am learning and reading a lot. It is just different from other cars I have owned. I apologize for asking a dumb question.
I have been learning about storage for 5 months or so. I am going to put a trickle charger on the main battery and leave the aux battery alone because I cannot easily get to it. When I read here, it seems everybody uses or recommends the CTEK battery maintainer. I also read about being careful about overcharging.
I have had several boats and cars and always used the Battery Tender brand and used Battery Tender Junior on other things. I already have some of these other brands. I think one is a NOCO or something like that.. Is there a reason to go buy a particular CTEK for the SL. I don't mind doing this if the consensus is that I need to. If so, which CTEK should I buy? I saw different ones on Amazon. If it was anything BUT this SL, I would not even be asking this. I am just trying to learn and find the right way to care for it while we are away this winter... Thanks.
I have been learning about storage for 5 months or so. I am going to put a trickle charger on the main battery and leave the aux battery alone because I cannot easily get to it. When I read here, it seems everybody uses or recommends the CTEK battery maintainer. I also read about being careful about overcharging.
I have had several boats and cars and always used the Battery Tender brand and used Battery Tender Junior on other things. I already have some of these other brands. I think one is a NOCO or something like that.. Is there a reason to go buy a particular CTEK for the SL. I don't mind doing this if the consensus is that I need to. If so, which CTEK should I buy? I saw different ones on Amazon. If it was anything BUT this SL, I would not even be asking this. I am just trying to learn and find the right way to care for it while we are away this winter... Thanks.
Super Member
Joined: Oct 2005
Posts: 997
Likes: 260
From: Frisco Colorado, USA
2024 GLB35 AMG, 2020 S560 Coupe
First off, yes I am a little gun shy about this car. It intimidates me a little so far, but I am learning and reading a lot. It is just different from other cars I have owned. I apologize for asking a dumb question.
I have been learning about storage for 5 months or so. I am going to put a trickle charger on the main battery and leave the aux battery alone because I cannot easily get to it. When I read here, it seems everybody uses or recommends the CTEK battery maintainer. I also read about being careful about overcharging.
I have had several boats and cars and always used the Battery Tender brand and used Battery Tender Junior on other things. I already have some of these other brands. I think one is a NOCO or something like that.. Is there a reason to go buy a particular CTEK for the SL. I don't mind doing this if the consensus is that I need to. If so, which CTEK should I buy? I saw different ones on Amazon. If it was anything BUT this SL, I would not even be asking this. I am just trying to learn and find the right way to care for it while we are away this winter... Thanks.
I have been learning about storage for 5 months or so. I am going to put a trickle charger on the main battery and leave the aux battery alone because I cannot easily get to it. When I read here, it seems everybody uses or recommends the CTEK battery maintainer. I also read about being careful about overcharging.
I have had several boats and cars and always used the Battery Tender brand and used Battery Tender Junior on other things. I already have some of these other brands. I think one is a NOCO or something like that.. Is there a reason to go buy a particular CTEK for the SL. I don't mind doing this if the consensus is that I need to. If so, which CTEK should I buy? I saw different ones on Amazon. If it was anything BUT this SL, I would not even be asking this. I am just trying to learn and find the right way to care for it while we are away this winter... Thanks.
I purchased a CTEK for my GTS that has a lithium battery which requires a special charger, but for all my other vehicles over decades, I've used Schumacher brand trickle chargers that I've purchased from AutoZone or similar store. I see no reason to do otherwise.
MBWorld Fanatic!
Joined: Dec 2015
Posts: 1,636
Likes: 522
From: Hagerstown MD
2015 SL400; 2019 X5M40i
I have several Battery Tenders and have used them on numerous cars and lawn tractors. They work well. I also have 2 CTEK units and have started using them on my SL and my X5. They are a more sophisticated unit and allow for closer monitoring of the status of the charging and maintaining process. They also have a mode that can desulfate and renew a lead acid battery as well as a setting that is used on AGM batteries. You can find the CTEKs on Amazon for a very good price. This is the one I prefer:
CTEK - 40-206 MXS 5.0 Fully Automatic 4.3 amp Battery Charger and Maintainer 12V (40-206)
Super Member
Joined: Jul 2018
Posts: 563
Likes: 171
From: Nothern Georgia, U.S.A.
'17 SL450, '25 Lyriq, '25 Sonata Hybrid, '96 Corvette GS coupe
Mine is a CTEK MUS 4.3. It is rated for AGM batteries...of which we have two in our SLs. I bought two of them when I got the SL, intending to install one on the auxiliary battery. I haven't installed that one, as I'm now of the opinion that the aux battery is fine with the natural maintenance of the car's charging system...that is, as long as the aux battery is in good condition. I just connect a CTEK to the jump terminals under the hood and forget about the batteries. So far, with the car sitting that way for months at a shot it has been fine. What I like about the CTEKs is that they have a series of eight L.E.D.s on their display that lets you know what they're actually up to at any given time.
Last edited by Dr. Manhattan; Nov 17, 2020 at 07:23 PM.
