We have a 2003 S430 with the original battery. All is fine, unless we leave the headlights on.... After 3 hours, it needs a jump.
Other than that, it is fine. So, the question is..
Do we need a new battery or shut off the lights..

Thanks

Second question,
If we need a new battery, whose?

 

you leave the headlights on, with the car off, for 3 hours? No battery can withstand that, new or old.

Dont just "jump" the car, then keep using it. The battery is still weak and you will tax your alternator too heavily.

Take the battery out of the car, and have it charged and tested. if you dont , you are putting tremendous strain on the alternator trying to bring a nearly dead battery back to full capacity.

at 7 years you probably are nearing the end of the battery lifecycle. Most people recommend the original Mercedes battery. But its costly. Your current one might have another year or two in it if you follow the procedure above.

 

I would replace the battery regardless of whether it checks out okay or not. Seven years is a long time for one in a car used regularly. I live in S. Florida where I've never gotten more that about 3 years out of one which is due to hotter temps.

I periodically test mine and generally replace them every 3 years or so as I don't want a call from the wife at the mall saying the car won't start. Moreover, jumping MB's can get a little dicey as doing so incorrectly can send an electrical spike through the system resulting in possible damage to the electronics. And as stated above, alternators are not design to charge batteries. Doing so can shorten their lives.

 

I know many will not agree with me on this one but I put in a Walmart battery last year in my S55 and it still works perfect! I spent well less than $100 on it and it has a great warranty.

 

There is only a few manufacturers of batteries in the World. Johnson Controls probably produces the most including those for Walmart. Have a look:

http://www.themanufacturer.com/us/pr...hnson_Controls

 

Thanks for the info Jud.
Funny how it seems most batteries are all the same but can cost so different.
Just another example of to many hands in the pot.
Johan

 

lets be clear. Although many different retail brand names may be produced by johnson controls or similar, that doesn't mean the actual batteries are all the same.

 

Out of curiosity, do you have any research on this?

 

My experience with 3 W220's is that the MB battery lasts 4 years. The MB unit is a gel battery which withstands shakes, rattles and bumps better than normal lead/acid batteries.

 

I believe the OEM w220 battery technology is called AGM (absorptive glass mat) instead of traditional lead acid plates.

 

Yeah, it was based on destructive analysis on the thickness of the plates or whatever, as well as returns and other stuff. I'm not an electrical engineer so i didn't understand all of it.

Regardless, for some reason interstates seem to be better than diehards or delcos.

Let me see if I can find the write up, its been a few years.

 

Go with MB roadside service, only $150 for oem battery, free installation, and they will come to you. Just did mine 2 months ago.