SL/R230: AUXILIARY BATTERY NOT LASTING
Thread Starter
Senior Member
Joined: Oct 2021
Posts: 493
Likes: 101
From: Benton, Louisiana, USA
SL 500 2004, Ford F-150-2014
AUXILIARY BATTERY NOT LASTING
Ladies, gentlemen R230 owners..I have been using the DURACELL AGM battery as auxiliary battery since I own my SL500 and have changed the battery 3 times in 3 years since they only last less than a year. I wonder if any of you have had the same experience and if not what would be the long lasting choice!
Thank you and keep on rolling in style!
Thank you and keep on rolling in style!
Senior Member
Joined: Apr 2023
Posts: 482
Likes: 306
2014 S63 2010 ML350 Bluetec 2009 SL550
How often are you driving the car ? These don't like to sit and discharge and that will definitely shorten the battery life.
Get a Battery Tender or something similar to keep a trickle charge on it and it should last 6-8 years easy.
Get a Battery Tender or something similar to keep a trickle charge on it and it should last 6-8 years easy.
Newbie
Joined: Jan 2023
Posts: 7
Likes: 1
Mercedes Benz SL500 R230
Auxiliary Battery Not Lasting-Possible Solution
Ladies, gentlemen R230 owners..I have been using the DURACELL AGM battery as auxiliary battery since I own my SL500 and have changed the battery 3 times in 3 years since they only last less than a year. I wonder if any of you have had the same experience and if not what would be the long lasting choice!
Thank you and keep on rolling in style!
Thank you and keep on rolling in style!
I still have the same battery and has been reliable with 12.3 volts at rest .
The only thing I added to negative terminal of battery is a quick connect/ disconnect switch . I use a trickle charger just prior to starting the car and believe that’s the reason the battery hasn’t failed.
The downside is that to connect the switch I have to unlock the trunk using the key and after the car starts have to syncronize the windows and the steering angle.
Same starter battery also still works great.
The only other thing I do when I park the car in the garage is shut the car down and disconnect battery.
I leave the battery connected when I park the car for hours and lock and put the car to sleep mode by pressing the key fob twice.
Just a suggestion.
MBWorld Fanatic!
Joined: Mar 2008
Posts: 1,232
Likes: 168
From: Glasgow, Scotland, UK
SL 350 R230 (3.7L with AMG Speedshift autobox)
I would strongly advise using a genuine Mercedes Battery, I have used Duracell and other off brands and they do not compare to the genuine product, if you cant leave your car for 3 ro 4 weeks without low voltage issues, you have a drain.
