SLDOUG

2013 SL 550 R231
Good day to all,
Well I have been fortunate to be able to drive on my original 2013 Main battery for the last 10years and its still working great but so not to push my luck I will be changing it now.
The car is in winter storage with a trickle charger keeping both batteries alive and it’s connected to the + battery post under the hood ant to ground.
I would like to know if I leave this trickle charger connected during the battery change is sufficient to act as a memory saver.
thanks for your help
best regards
SLDoug

hornethandler

Most chargers/maintainers are safetied to prevent them from outputting voltage unless they are connected to a voltage source (battery) that has a minimum voltage--not sure what that is, but probably in the 9/10 volt range. So, connecting it to the vehicle when the battery is removed won’t help. Also, it’s my understanding the vehicle monitors battery health (capacity) over its life and varies the charging routine (cycles/rates) to compensate for battery aging. So, “battery registration” may also be required to tell the vehicle a new battery is installed.

Sorry for the not so encouraging feedback.

For the purpose of maintaining your vehicle settings, a small 12-volt battery, or two 6-volt lantern batteries connected in series, will probably do the job.

Good luck!

JettaRed

iTrader: (1)

I've never had a memory problem disconnecting the batteries. You may get some stored codes due to low (i.e., zero) voltage, but those are easily cleared with a proper scanner.

Do our cars even have battery registration?

hornethandler

Not sure about the registration... maybe only the newer models. I'm pretty sure my other vehicle registers the battery.

crconsulting

No battery registration on R231. Also note it says to re-set clock, implying no battery specified/needed to preserve anything critical in the onboard memory.
see battery R&R from the WIS posted in the battery replacement thread.
https://mbworld.org/forums/sl-class-...ml#post8955490

SLDOUG

Thanks for your input, I did not know that but it makes sence. These trickle chargers aka smart chargers will only go on when required so as you say they wont do the job.
Regards
SLDoug