shotgun_banjo

Was cleaning the engine bay of the new to me 2010 C207 and removed the air box cover and saw a tiny H6 AGM battery. It is too small that it wont clamp down. I need to replace this thing before it decides to jump and destroys the box and other stuff. Upon looking at the online stores it gives H6, H7 and H8 sizes. So either ot is a H7 or H8 but wont risk buying the wrong one so help out if you know the original size.

Quint22

Coupe H7 sedan H8 from what I have read. Pretty easy search.

https://mbworld.org/forums/e-class-c...y-fitment.html

Left Coast Geek

diesels tend to use the largest battery sizes

shotgun_banjo

Thanks for the link. H7 it is then.

Left Coast Geek

all of those H batteries (there's an H9 too) should be held down by clamps on a flange on the bottom of the 'front' and 'back' side of the battery. all of them are the same ~ 6 7/8" deep and ~ 7.5" high (really, 175mm x 190mm), the H6 is about 9.4" wide, the H7 is 11" wide, the H8 is almost 14" wide, and the H9 is about 15.6" wide. You should always be able to physically fit a smaller H size into a larger H tray.

kajtek1

Generally yes, but for US, it is the list of gadgets, what require bigger battery capacity. Those power seats, who operate without engine starting, safety lights that stay on after you lock the vehicle take some extra power.
But European version often have H6 batteries for V6 diesels, when in US everything goes H8.
When you are in cold climates, you can use the extra capacity for seat heaters, but in warm climates, you are carrying extra dead weight.
You can still buy flooded H6 for about $80, when good looking one at Costco is about $110.

ygmn

where are you buying batteries for $80?

Local costco here has them for $170

Lowest I find for decent name brand is $160.

Left Coast Geek

These cars are supposed to have AGM batts.

JettaRed

iTrader: (1)

Concur. The importance of getting the right and proper battery cannot be overstated since modern Mercedes cars are so temperamental when it comes to electrical sources. The wrong battery will cause all sorts of phantom problems. It is generally recommended to get genuine Mercedes batteries from the dealer. (However, I haven't but paid enough for the ones I got that the dealer would have probably been cheaper.) Definitely need to stick to AGM batteries. AGM and traditional (Flooded/Wet Cell) batteries have different charging profiles. Putting a flooded battery in place of an AGM battery may cause over-charging.

Flooded Batteries vs. AGM Batteries: Understanding the Differences - Power Sonic (power-sonic.com)

Left Coast Geek

FWIW, our E350 has done just fine with a East Penn Deka "Intimidator" AGM 9A49 (Group 49 aka H8).

JettaRed

iTrader: (1)

And this is what I currently have in my SL400. I replaced both my batteries when I would have random blind spot failures. Not sure if both needed to be replaced, but I did anyway. I have the old batteries on CTEK trickle chargers.