Mercedes E-Class (w124) battery question

[DaBump]

Hi Everyone. I bought a mercedes e-class (w124 shape) 230E automatic two days ago. Fine vehicle, and relative good condition for it's 22 year old age. When I got to the car yesterday afternoon, after standing for aprox 20 hours, it did not want to start. I drove it around for a couple of minutes, and this afternoon the battery was dead again.

Could this be the battery or the alternator? As far as I know, the alternator will charge the battery as you drive, but if the alternator was not working properly, the car would not run. I took it for a 30 km drive this evening, with lights, etc..But when I tried to crank the starter, you could hear it's battling to start.

What's your thoughts? new battery? Or alternator?

 

[thedutchman]

well how old is the battery ?

 

[DaBump]

i've got no idea...

 

[thedutchman]

i think you should go to hiQ or some other battery place and have it both checked

 

[spiderz]

Go to a place that sells batteries and ask them to test the battery. Two types of test they can do, test the scid level or something in each cell, or do a load test on the battery. Both will be able to tell you if battery is dead or not.

Quick test for the altenator is just to measure the voltage on the battery.
With the car running the altenatro should output about 13-14.5V. When you switch off the car the battery should output 11.5 -12V.

 

[DaBump]

Thanks alot guys...Battery was dead, one cell...Alternator working 100% Appreciate all the help!