Trickle charging through 12V socket (cigarette lighter)?
 

Hi folks, question about keeping my SL55 batteries happy and charged. Any issues with using a trickle charger that plugs into the 12V socket (cigarette lighter socket) in the SL?

I've experienced a couple of times that the accessories battery is dead/low after not running the car for a week or so. Of course, the primary battery still starts the car and the secondary charges after a few minutes allowing the roof and other electronics to work.

I just wanted to check what folks are doing to keep their batteries ready to go.

I don't believe it works in a Mercedes SL due to the electrical system design....search posts on this....I tried it with mine and it did not work as lighter is not a "hot" circuit......

Works in my Porsche lighter that has "hot" circuit.......i.e. charges my iphone when car is iff from the lighter, etc....

Not sure either, but I know a very simple trickle on the trunk (consumer electronics) battery works like a champ all winter long for me. My car sits for four or five months without a start. When the first warm day in the spring comes, I jump in the SL, push the start button and the little monster awakes first time every time.

The trunk based trickle charge with the permanent mount is by far the best way to manage the SL's need for juice. My car has been MUCH happier on a steady 12v diet. Plus, it is simple as opening the trunk, unplugging, and off you go...Plus it will force you to replace those trunk struts youve been meaning to get to...one knot on the head is motivation aplenty.

+1 on all above...I've got my trickle charger on duty anytime it sits...which is about 6 days a week. You would think the company that made the first car would figure out a battery drain in our AMG's. The local MB shop was useless and they said buy a trickle charger from them...so I went on Amazon and bought 2 CTEK's for the price of one of theirs...

Ha! I did exactly that. It took a couple of knots for me though.

You can go to Autozone if you have a cigarette lighter charger and they have an adapter with clips that then clip onto the battery posts.......saves you buying a ctek or similar trickle charger unit for one of the batteries, as you also need to charge the starter battery in the engine bay from time to time - it discharges slower, but I had to replace sooner than the trunk battery at year 6.....