sammydragon3

i got a new (my factory trained mercedes (they also have SDS) indy swears he never had a problem with them) diehard internation battery around 3k miles ago...everything is fine of course then temp drops to 30F car struggles to start sometimes

so i get in the car put it in dyno battery reads 12 volts i didnt start it at all yet

i start the car (struggles pretty bad) voltage reads 13.8 volts

i rev the car to 2k rpm voltage is at 14.2 volts

terminals look ok but have little white on them...i would assume they would clean them when they replaced the battery

thank you

80k miles never had a break down yet i hope this winter im not on the side of the road

sammydragon3

help?

torake

What is your voltage over the battery during cranking?

phister

Does the battery CCA match the requirements the mb battery has.

pcy

Fully charged battery should read 12.6V.
The battery on your car reading 12V - this indicates the battery is around or less than 25% charge.

If I were you, I'd charge the battery with a trickle charger.
Then, have the battery LOAD TESTED to see if it holds the charge during the starting cycle.
AutoZone and Pepboys test the battery for free. If I remember correctly, they do test with a load tester.

sammydragon3

I thjnk the battery is 850 or 860 cca

Ill check the battery wen crankin in the morning

How do u kno if the alternator is going bad?

pcy

When the voltage is less than 14V when the engine is running ==> alternator on it's way out.