A year ago I had a diehard battery that did that. It "Tested good" at sears (scam artists) yet didn't have much umph in my car to fire it up. Since it tested "good" they refused to replace it. So, I murdered the battery. Hooked up my power inverter to it with a halogen shop light and drained it till it was dead. Charged it again, and repeated that about 4-5 times until it could only run the light for a short while. I then brought it to a different sears, they tested it as "bad" and gave me a new one....its on the shelf as a spare though, since I had already bought a MB battery from roadside assistance.

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

yea.. Mercedes said they could bring me a battery.. I should have since the nice white battery is probably 10$ more than the G49 from the mcparts place..

I'm not trying to say that I trust the McParts counter guy to know whether the battery really is good, just that your starter is probably not taking 300A. They probably did not test it at 300A, even if they thought that they did.

I do like Pawo's suggestion, as unethical as it sounds.

I was going to do something like that... ^_^ .. anything for a new battery..

I dont think I have ever bought a battery under 750CCA. I bought 2 875CCA batteries for the excursion now that the florida heat killed the other two. when you say 300 amps are you talking about CCA? No wonder it didnt last.

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1982 300CD Turbo (Otis, "ups & downs") parts for sale
2003 TJ with Hemi (to go anywhere, quickly) sold
2001 Excursion Powerstroke (to go dependably)
1970 Mustang 428SCJ (to go fast)
1962 Corvette LS1 (to go in style)
2001 Schwinn Grape Krate 10spd (if all else fails)

my old battery was 850 CCA same as the new


When I got home tonight from work I noticed that when I rev the engine the lights get a little brighter... normal I bet

I never put much stock in the smiling faces at AZ/etc to test my batt -- when the cranking started to slow down, I just went & got a new AZ batt - their best, probably. I figured that would elim a variable if nothing else. I was lucky -- that was 3 yrs ago & no trouble since.