buzzy123`

Hi Guys,

Thanks for all the great posts that have helped in the past, i've lurked, but now have an issue i hope you can help with. my sl55 has battery issues, after leaving it unused for 6 months, The electrics battery seems to be dead, and just a week ago teh red message on the dash came up to visit workshop for the front battery, although the car is starting up pretty much as it has always. so am wondering, is the rear battery affecting the front one, and creating the message concerning the starter battery? hoping to not replace the batt if it's just getting confused with the lack of charge on the back battery. Also, what are the chances the rear is just discharged and would be ok with a charge? not great i bet. Thanks guys!

PS Sorry about posting this here, but not seeing the link to post in tHE appropriate forum.

MJ50

moved to R230 AMG forum...

kbob999

Any SL sitting 6 months is likely to have battery issues, especially the rear.
Put a battery tender brand, or MB model charger on it...one that switches off when charged, and works on AGM batteries.

If the battery does not hold that charge for a couple days...and you get 'consumer electronics' error on the dash...replace the rear battery. Once bad, they stay bad.

Front battery is only for starting, so it rarely has issues. Check voltages at each battery to confirm.

There is a complicated voltage monitor that shares electrons to and from both batteries, so the car will still work when one fails.

cal1

+1 If I know my car is going to sit for a week, I plug in the my trickle charger. I have the quick disconnect wire permanently attached to the trunk battery so it is very easy. The car sits that way all winter and starts up in the spring like I had just started it the day before.

euphoriaDSM

The rear battery is dead and will cause all kinds of strange behavior from the car. Just go ahead and change it, doesn't have to be a Mercedes battery, and I bet all the problems will disappear.

55slamg

I use 2 battery tenders, one for each battery if I plan on not driving for a few weeks. Without tenders, 3 weeks sitting idle will bring on the red warning that consumables are not available.