Date registered: Nov 2002
Vehicle: 10 GLK 350 4Matic
Location: Sonoma County CA
Mentioned: 0 Post(s)
Quoted: 10 Post(s)
RE: battery death warning
Batteries are tested ( even today[:)]) by measuring their standing voltage - at rest not having been charged or starting a car in the last ten minutes. They should read about 13.75 volts.
They are then discharged at a consistent rapid pace for 5 to 10 minutes. They ending voltage is measured. If in that short time it drops below 12.25 volts it's considered on its last legs. A good parts store or auto battery store can do this test - but realize a lot of them are anxious to sell you something.
The typical lead-calcium flooded cell ( your typical starting type battery) signals it's near the end of life by bouncing back slowly and not hitting the old peaks. It will crank the car a little more slowly and in stop and go trips and will seem to not come back up to charge fast enough.
The Optima is an excellent battery. It is a sealed spiral cell battery with very low amounts of acid in a mat wrapped between the plates. It can give a lot of power for its size and can have a long life. A couple things - they are very expensive for what they give you and they are very sensitive to overcharging. They can lose their very small amount of electrolyte through a pressure valve if the voltage isn't carefully controlled. Most Mercedes with microprocessor based voltage management systems should be OK ( if you don't mind the $$$) but the older relay based systems - such as a 240D may not be up to the task.[xx(] Your typical DieHard or Interstate batteries are much better at this - and at 1/3 the price.
Check yor local Interstate distributor. They commonly sell seconds and blem's for $30 or so. It's an incredible deal on a very good battery. They can't sell first runs because that conflicts with their retail shops but do you really care if the label on a battery is a little crooked? If that's not practical your best deals are a Sears sale on DieHards,or WalMart, PepBoys or Costco...
Buy all the AmpHour and Cold Cranking Capacity you can properly fit in the holder.
Now: 2010 GLK350 4Matic Then: 2003 C320 4Matic, 2006 E320 CDI, 2000 E320, 1994 E320, 1991 190E, 1985 300D, 1983 300D
"Too much of anything is bad, but too much of good scotch is barely enough."