Battery Tender
#1
Newbie
Thread Starter
Battery Tender
Hello! Will be heading out soon to escape cold weather for 3 months for first time. Buying a battery tender. Dumb question.. how do you run the cord/cable into the rear battery - through trunk? And does trunk hatch stay open? Many thanks in advance!!
#3
MBWorld Fanatic!
Join Date: May 2018
Location: Long Island, NY
Posts: 2,104
Received 600 Likes
on
455 Posts
2019 E 450, 2016 E350 4matic (retired), 2018 Ford Edge Sport, 2008 Porsche Boxster
My observations:
I have a tender that plugs into the 12 volt socket. Works spectacularly in my 2008 Porsche Boxster as the receptacles are "alive" even with the ignition turned off.
Tried it on my 2019 E450: did not work as the 12 volt receptacles turn off, are "dead" without the ignition on.
Has anyone found a 12 volt that remains "live" after ignition turns off? If not, then the tender must go directly to the battery.
I have a tender that plugs into the 12 volt socket. Works spectacularly in my 2008 Porsche Boxster as the receptacles are "alive" even with the ignition turned off.
Tried it on my 2019 E450: did not work as the 12 volt receptacles turn off, are "dead" without the ignition on.
Has anyone found a 12 volt that remains "live" after ignition turns off? If not, then the tender must go directly to the battery.
#4
MBWorld Fanatic!
For some reason my '18 E300 did not come with 12v sockets. I have a 110v ac socket. I use the battery connection in the engine compartment for the battery tender. I've considered installing a 12v socket, but haven't gotten around to it.
#5
MBWorld Fanatic!
Join Date: May 2018
Location: Long Island, NY
Posts: 2,104
Received 600 Likes
on
455 Posts
2019 E 450, 2016 E350 4matic (retired), 2018 Ford Edge Sport, 2008 Porsche Boxster
So far on my 2019 E450 I have found two:
Has anybody discover a third or fourth, one of which may be live?
- One in the front passenger foot well;
- Another in console between the front seats. You access it from the rear passenger seat. It is directly below the two air vents.
Has anybody discover a third or fourth, one of which may be live?
#6
MBWorld Fanatic!
Join Date: Jul 2013
Location: Venice Florida
Posts: 4,542
Received 669 Likes
on
525 Posts
2018 S560 and 2019 E450 Wagon.
Just a funny thought. I wonder how many people try and plug their battery tender into the 120v outlet in the car😀🔥. My e450 has a battery positive with a sliding shield over it and a negative terminal right under the hood. Simple.
#7
MBWorld Fanatic!
Join Date: May 2018
Location: Long Island, NY
Posts: 2,104
Received 600 Likes
on
455 Posts
2019 E 450, 2016 E350 4matic (retired), 2018 Ford Edge Sport, 2008 Porsche Boxster
Dear 2012 Merc amg:
12 volt receptacle:
As I posted I have one in the passenger foot well and another in the console between the front seats that faces the rear seats.
Have you found another and if so, where is it and is it live? I would like to use my tender which only provides for using the 12 volt receptacle. which must be "live". It does not have an extra set of wires to hook up directly up to the battery. I prefer to use what I have, rather than going out and purchasing another tender that will hook up to the battery.
12 volt receptacle:
As I posted I have one in the passenger foot well and another in the console between the front seats that faces the rear seats.
Have you found another and if so, where is it and is it live? I would like to use my tender which only provides for using the 12 volt receptacle. which must be "live". It does not have an extra set of wires to hook up directly up to the battery. I prefer to use what I have, rather than going out and purchasing another tender that will hook up to the battery.
Trending Topics
#9
MBWorld Fanatic!
Join Date: Jul 2013
Location: Venice Florida
Posts: 4,542
Received 669 Likes
on
525 Posts
2018 S560 and 2019 E450 Wagon.
Yes just front battery. I just leave hood open never had a problem even after 6 months.
I use a Shulmaker maintainer. It’s 30 dollars at home depo. It has both hardwire or alligator clamps. On my truck I have it hardwired and just a simple plug in connection. On the Benz it’s easier just to use the alligator clamps
I use a Shulmaker maintainer. It’s 30 dollars at home depo. It has both hardwire or alligator clamps. On my truck I have it hardwired and just a simple plug in connection. On the Benz it’s easier just to use the alligator clamps
The following users liked this post:
spencer05 (12-16-2019)
#11
MBWorld Fanatic!
Join Date: Jul 2013
Location: Venice Florida
Posts: 4,542
Received 669 Likes
on
525 Posts
2018 S560 and 2019 E450 Wagon.
Nope that’s the only two 12 volt recepticals. My 2018 had one in the front ashtray compartment too. But the 2019s just where you said and the inductive cell phone charger
#13
MBWorld Fanatic!
Join Date: May 2018
Location: Long Island, NY
Posts: 2,104
Received 600 Likes
on
455 Posts
2019 E 450, 2016 E350 4matic (retired), 2018 Ford Edge Sport, 2008 Porsche Boxster
This charger is made by CTEK for Mercedes. Putting the "Mercedes" name on the charger doubles the price.
If you want a CTEK charger, here is the one I recommend:
If you want a CTEK charger, here is the one I recommend:
https://www.amazon.com/CTEK-56-865-Automatic-Battery-Charger/dp/B006CQ9BMO/ref=asc_df_B006CQ9BMO/?tag=hyprod-20&linkCode=df0&hvadid=241948264947&hvpos=1o1&hvnetw=g&hvrand=18073106888978373592&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9004329&hvtargid=pla-571026350836&psc=1
The following users liked this post:
spencer05 (12-16-2019)
#15
The following users liked this post:
Cerave (12-16-2019)
#17
MBWorld Fanatic!
This is the 5-amp charger/tender you want. It's a later generation than the MB-branded one, and cheaper.
#18
MBWorld Fanatic!
Join Date: Jul 2013
Location: Venice Florida
Posts: 4,542
Received 669 Likes
on
525 Posts
2018 S560 and 2019 E450 Wagon.
Glad your getting a maintainer Spencer. I too am a snowbird. I use this one available at home depo. Has never let me down. I like that it goes into eco mode and the green light slowly flashes on and off and I can see it with my video camera I have in my garage https://www.homedepot.com/p/Schumach...1248/207123536 know everything is alright. For $25.00 cant go wrong. I just put my car on it tonight as about once a month I give the battery a good charge as my Cabriolet sits around a lot and tends to get drain and then my cell phone alerts me the charge state is critically low.
The following users liked this post:
spencer05 (12-16-2019)
#19
MBWorld Fanatic!
This charger is made by CTEK for Mercedes. Putting the "Mercedes" name on the charger doubles the price.
If you want a CTEK charger, here is the one I recommend:
https://www.amazon.com/CTEK-56-865-A...26350836&psc=1
If you want a CTEK charger, here is the one I recommend:
https://www.amazon.com/CTEK-56-865-A...26350836&psc=1
The following users liked this post:
spencer05 (12-17-2019)
#21
MBWorld Fanatic!
Join Date: Feb 2014
Location: MA
Posts: 6,147
Received 1,503 Likes
on
1,174 Posts
2008 E350 4Matic, 2011 E350 4matic
The following users liked this post:
spencer05 (12-17-2019)
#22
MBWorld Fanatic!
Just get an 8amp charger. Not much more money than what you previous mentioned.
https://www.amazon.com/Schumacher-SC1279-12V-Rapid-Charger/dp/B07DM22XTN
https://www.amazon.com/Schumacher-SC1279-12V-Rapid-Charger/dp/B07DM22XTN
The CTEK MXS 5.0 takes the battery through eight phases:
1) Desulfation, using rapidly pulsed 15.8V, current-limited cycles if it detects this condition (usually on an older battery).
2) Soft start, applying 4.3A constant-current until the battery is charged to 12.6V.
3) Bulk charge, increasing voltage from 12.6 to 14.7, at 4.3A for a max of 20 hours.
4) Absorbtion, applying decreasing current at 14.7V, for up to 8 hours.
5) Analysis of condition, three minute load cycle with check that voltage does not drop to 12V.
6) Optional recondition phase, if selected, that attempts to salvage old battery by applying 1.8A at 15.8V for 6 hours.
7) Float, maintain at 13.6V with 4.3A.
8) Pulse, apply pulsed waveform between 12.7V and 14.4V (4.3-2.5A)
Phases 7 and 8 are the tender mode, and alternate to maintain or charge as needed.
All the voltages and currents I quote are for automobile AGM batteries. If the CTEK is set to non-AGM or motorcycle battery (AGM or non-AGM) different values are use. The voltages are also adjusted for temperature using an on-board thermistor.
The technology is this charger is amazing, and is designed to safely maintain an AGM battery in peak condition. It is not comparable to cheaper chargers that apply a compromise, but constant current at a compromise, but constant voltage regardless of battery type, state of charge, temperature, battery size, etc.
As far as I'm concerned this charger is the best accessory I've ever bought for my E63S.
The following users liked this post:
spencer05 (12-17-2019)
#24
MBWorld Fanatic!
Join Date: Jul 2013
Location: Venice Florida
Posts: 4,542
Received 669 Likes
on
525 Posts
2018 S560 and 2019 E450 Wagon.
I've been using Shumachers for 20 years and never had any issues. I've left cars on them for 6 months at a time and they have never let me down. The only Battery I've had to replace was the smaller starter battery on my 2015 S550 Benz, but those are only good for so long anyhow, like 3 years. Glad these newer cars got rid of that setup, those were trouble prone. My 2019 E450 Cabrio is on my Shumacher now and it is fully charged, it took a day, but I don't care, there is no rush to charge it. I guess I'll put that car on it once every few weeks or so just to top it off, otherwise I seem to get a low battery critical message on that car as it sits around a lot. It is only a 1.5 amp maintainer. It's all I really need. I've had one like this one for the past ten years , it is multi stage charging, no problems. I have a newer one that is a lot lighter and slightly different design that I have on my Truck up north right now. It's about 3 years old and used 6 months at a time, no issues.
Last edited by 2012 merc amg; 12-17-2019 at 11:25 PM.
The following users liked this post:
spencer05 (12-17-2019)
#25
MBWorld Fanatic!
I've been using Shumachers for 20 years and never had any issues. I've left cars on them for 6 months at a time and they have never let me down. The only Battery I've had to replace was the smaller starter battery on my 2015 S550 Benz, but those are only good for so long anyhow, like 3 years. Glad these newer cars got rid of that setup, those were trouble prone. My 2019 E450 Cabrio is on my Shumacher now and it is fully charged, it took a day, but I don't care, there is no rush to charge it. I guess I'll put that car on it once every few weeks or so just to top it off, otherwise I seem to get a low battery critical message on that car as it sits around a lot. It is only a 1.5 amp maintainer. It's all I really need. I've had one like this one for the past ten years ,https://www.amazon.com/Schumacher-SC...ZD85JGV4R&th=1 it is multi stage charging, no problems. I have a newer one that is a lot lighter and slightly different design that I have on my Truck up north right now. It's about 3 years old and used 6 months at a time, no issues.
The following users liked this post:
spencer05 (12-17-2019)