Hello everyone,

Since there have been numerous questions regarding Optima batteries but no formal writeup of any kind I decided to write one up for the AMG guys looking for a lighter battery option when it comes times to replace their old stock OEM battery (which for many of the older AMGs is right about now).

After looking at many of their batteries, it became obvious their lightest option (Yellowtop 51R) is simply not a good fit for our cars. The battery is just too tall for the battery tray and its not the best fit. The Red top 34R has also been mentioned quite a bit if you do a search for them but its also not the best likely candidate for a few reasons. First off its a tad bit on the heavier side compared to the #35 (spec weight is 38 vs. 32lbs) and also the battery terminals are much closer together toward the center making it further from the stock battery cables, so they may not be long enough to reach in some applications.

The #35 Red top is the ideal choice since it is one of their lightest batteries (second to the Yellow top 51R) and it has very similar height & width dimensions as the OEM unit it is just shorter in length by about 3". However, its terminals are at the ends of the battery so it fits much like a larger battery. Furthermore, the #35 redtop already has reverse poled terminals so its a direct drop in.

The hardware was only available at autozone, AdvanceAP didn't have the right kit (although a few other parts stores may have it). The Red circular pads included in the kids weren't needed so I simply discarded them. Rest is self explanatory.

The installation is in PDF form to make it easier for those who want to print it out or view off line at their convenience. I hope its as simple & easy to read/follow as possible (written for those with even the most basic hands on skill)

Hope that helps,
~AMS~

 

Thanks for the info, unfortunately I'm unable to view the PDF do you think you could post it on the forum? Also, what generally is the weight of the stock battery?

 

Maybe you just need to update your adobe reader, if anyone else has problems viewing it let me know. Thx

 

I could read the DIY PDF file - thanks for the info.

Does anyone know how much our stock battery weighs? Does Optima make a battery with a bigger capacity than the stock battery yet which is lighter?

I have an aftermarket sound system with a 4x135 watt Class A amp. Next week the installer is adding a second 1x400 Class D amp just to drive the 13 inch subwoofer (We're going for more boom boom). The installer recommends that I swap out the stock battery in favor of a monster Tsunami battery - which weighs 90 pounds! The installer says big batteries are better than capacitors for feeding amps. Of course, I don't want to pay too much of a weight penalty, even if more weight on the rear axle of a CLK AMG has its advantages. For the moment, I'm standing pat with the stock battery. But when it gives up the ghost, what should I do?

 

Personaly, I perfer a big heavy high AMP, high reserve Battery that was designed to fit exactly for my street car. I refuse to suffer any low voltage conditions that damage electronic hardware. One thing about lead acid batteries, bigger is better.
Please don't tell me how great Optima batteries are, or their claimed specs....been there....
Now if you have what you think is a race car, and every ounce counts then here is a link for the real weight saving battery.
http://www.voltphreaks.com/index.php

 

i had good luck with the odyssey 925.

 

The optima red tops have tons of reserve capacity, as do the yellowtops, both will do fine, especially compared to an older stock battery which is probably no where near its original specs after many years. You don't need such a heavy amp battery in warmer climates. You can easily get away with PC680 and that's only 650amp. But again as long as you properly maintain your and drive it properly then it should be fine. If you let your mercedes sit... then all sorts of problems can come up.

 

This tutorial must be for a W208, as my W209 has the battery mounted under the hood, at the right rear corner, instead of in the trunk. This looks just ike my old 1997 C class trunk mounted battery installation.

 

Yes, It's for a W208.

Great PDF writeup by the way! My battery is still working perfectly (knock on wood) but I have eyed this baby as its replacement so its nice to see how someone else did it and secured it properly!! Thanks

Greg

 

glad to be of service, It is the w208 correct. W210s have similar tray but under rear passenger seat. The same basic technique & materials can be applied to almost any mercedes.

Hope that helps.
~AMS~

 

I didn't know the 209 put the battery under the hood. That was a step backward, given the front heavy weight distribution. What does the CLK 63 BS do? Plenty of room back there in that car!

 

does anyone still have the pdf for this install? looked around and couldn't find anything, thx in advance!!