C300CA

MB battery charger is expensive.
I saw Sears has two trickle chargers. Both claim to be somewhat "intelligent"; when battery is fully charged, they will remain 'float'. One is rated 12V/1.5A and the other 12V/750mA.

I wonder if they are good for our cars.

AkaSigFreak

Why do you want a trickle charger? Do you plan on leaving your car for extended periods of time?

C300CA

First, C300 is my weekend car. Second, I might take long vacation sometimes. I don't need the charger any time soon, just want to know about it.

Carsy

I cannot see any problem with trickle chargers so long as they read the voltage & only supply milliamps when the battery is fully charged.

They are very useful when leaving the car unused for long periods & save the battery from discharge & the hassle of flatbedding or rapid charging on your return.

Emergency response vehicles use them for obvious reasons without trouble.

The correct type suitable for your situation must be used.

tc1728

i dont think your car would need a trickle charger, I sometimes dont drive my CLK for up to 4 weeks and it starts up just fine, on the other hand I do have a trickle charger for my QP, the battery will go dead in about 10 days if the charger is not plugged in. I got mine from Kragen for about $70, I can look up the part number if you want. TC

Ausmbtech

Try a ctek charger, either the 0.8amp or the 4amp model. These are the same as a genuine charger, easy to find on ebay.

A good quality charger will maintain your battery well, a poor quality charger will shorten the battery life.

C300CA

Oh yes, you reminded me seeing this charger months ago. I forgot it. I will buy that brand not the other, if I decide. Thank you.

downtowncanada

I would recommend a smart trickle charger, or better yet, a battery tender. Once a battery drops below 80%, sulfation starts to occur and reduces the life and performance of the battery. It's a cheap investment to keep the battery in top shape. I have the Battery Tender Plus 12V model which you can find online for around 50-60 bucks. I have to admit, MB's do a better job with battery management than BMW's with consumables.

I've owned 5 BMW's and 3 MB's and until I purchased the Battery Tender, my first 4 BMW's all required new batteries in the first year (under warranty thankfully) because they were always running down to 40% because of short trips, weekend use, vacations, winter storage, summer convertible top up and down, and cold weather (running seat heaters, defoggers).

Also, BMW's and MB's equipped with Comfort Access or Smartkeys automatically detect the keyfob near the car and turn on some electronics (Nav sat aquisition, door handle sensors activated for opening the doors, start the 125 Khz frequency data exchange) and those electronics are awake for a period of time. So everytime I was walking into my garage with the keys in my pocket, I was waking up the car. Which is fine if the car is driven every day.

The Battery Tender comes with connectors that you leave attached to the + and - posts under your hood and a quick-connect on the other end of it that you plug into the Battery Tender Unit on weekends, vacations etc. It will auto detect the battery type (AGM etc) and trickle charge at a very low amperage (i think 1.5A) and when the battery reaches 100%, it will drop off into float mode, and will wake up when needed to bring the battery back to 100. Just be careful as some trickle chargers say they have float mode, meaning they will turn on below 100%, but they risk overcharging the battery if they are not sensitive enough to recognize when the battery is back to 100% and turn off. Battery Tenders are smarter.

Carsy

Good info. JC