Hello-
My battery which I bought new 11/19/01 (60 month wet battery, EXI 49-60) died completely completely a week ago. I fully charged the battery and the car started fine until yesterday when it died again. My question is, how and what do I test to be sure that it is the battery and not something else. Please note also that the alternator was replaced 6/10/01. Any advise will be appreciated.
Ed

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Ed
1985 300D w/ 196,000 miles

ed, why don't you take a voltmeter and test the battery with the car off? it should be 12v - turn the car on and it should be 13.8 or so if the alternator is working right.
that's what i would do first.
have there not been some comments (negative..) recently here about exide batteries being defective?

btw - hope we will see you and your diesel at the upcoming new england gtg!!! (shameless recruiting plug. )

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1984 300D Turbo - 231k....totalled 11/30/07 RIP

You can run down to a local shop or even a reputable gas station with the right tools and have them load check the battery for you. Make sur eit is fully charged before taking it into them. This will generally tell whether or not it is bad.

You can also put it on a charger until fully charged. Disconnect it and either let it sit for four hours or apply a brief 20 amp draw to it to remove surface charge and then test the specific gravity with a good battery tester. Fully charged and at rest it should be 12.8 volts or higher. 10.5 volts is completely dead... There are calcualtions to validate charge based on temp but probably not needed.
Here is a chart from one of my RV forums that may help, good luck!

Use an external constant current charger which is set not to deliver more than 12% of the RC rating of the battery and monitor the state-of-charge.
For fully discharged batteries, the following table, published by BCI, lists the recommended battery charging rates and times:

Reserve Capacity Slow Charge Fast Charge
(RC) Rating

80 Minutes or less 15 Hours @ 3 amps 5 Hours @ 10 amps

80 to 125 Minutes 21 Hours @ 4 amps 7.5 Hours @ 10 amps

125 to 170 Minutes 22 Hours @ 5 amps 10 Hours @ 10 amps

170 to 250 Minutes 23 Hours @ 6 amps 7.5 Hours @ 20 amps

Above 250 Minutes 24 Hours @ 10 amps 6 Hours @ 40 amps

The BEST method is to SLOWLY recharge it using an external constant voltage (or tapered current charger) because the electrolyte has more time to penetrate the plates. A constant voltage "automatic" charger applies regulated voltage at approximately 14.4 volts. A 10 amp automatic charger will cost between $30 and $60 U.S. at an auto parts store.

3. HOW DO I TEST A BATTERY?

A. Visually inspect for obvious problems, for example, damaged case, corroded terminals or cables, loose hold-down clamps or cable terminals, or low electrolyte.

B. If you have just recharged your battery, then eliminate any
surface charge by one of the following methods; otherwise, go to the next step:

1. Allow the battery to sit for two to three hours,

2. Apply a 25 amp load for three minutes and wait five minutes, or

3. With a battery load tester, apply a 150 amp load for 10-15 seconds.

C. Use the following table, determine the battery's state-of-charge.
The best way to measure the state-of-charge is to check the specific gravity in each cell with a hydrometer. A temperature compensating hydrometer will cost approximately five dollars (this is not an accurate number anymore) at an auto parts store. If the battery is sealed, then the correct procedure to test it is to ensure the battery's voltage with a good quality digital DC voltmeter with an accuracy of .5% or better.

Open Circuit Approximate Average Cell
Battery Voltage State-of-charge Specific Gravity

12.65+ 100% 1.265+

12.45 75% 1.225

12.24 50% 1.190

12.06 25% 1.155

11.89 0% 1.120

[If the temperature of the electrolyte is below 70 degrees F (21.1 degrees C), then add .012 volts (12 millivolts) per degree below 70 degrees F to the reading. A 100% state-of-charge for a AGM (absorbent glass mat) battery will be approximately 12.80 VDC and 12.90 VDC for a gel cell.]

Check both the specific gravity in each cell with a external hydrometer AND the battery terminal voltage with a digital voltmeter without the engine running. For sealed batteries, measuring the battery's voltage without the engine running with a digital voltmeter is the only way you can determine the state-of-charge. Some batteries have a built-in hydrometer which only measures the state-of-charge in ONE of it's six cells. If the indicator is clear or light yellow, then the battery has a low electrolyte level and should be refilled before proceeding, or if
sealed, the battery should be replaced.

If the state-of-charge is BELOW 75% using either the specific gravity or voltage test or the built-in hydrometer indicates "bad" (usually dark), then the battery needs to be recharged BEFORE proceeding. Replace the battery, if one or more of the following conditions occur:

1. If there is a .050 or more difference in the specific
gravity reading between the highest and lowest cell, you have a weak or dead cell(s),

2. If the battery will not recharge to a 75% or more
state-of-charge level or if the built-in hydrometer still
does not indicate "good" (usually green, which is 65%
state-of-charge or better),

3. If digital voltmeter indicates 0 volts, you have an open
cell, or

4. If the digital voltmeter indicates 10.45 to 10.65 volts,
you have a shorted cell. [A shorted cell is caused by
plates touching, sediment build-up or "treeing" between plates.

4. WHAT DO I LOOK FOR IN BUYING A NEW BATTERY?

A. Reserve Capacity or Ampere Hour Rating

The most important consideration in buying a deep cycle battery is the Reserve Capacity (RC) or Ampere Hour (AH) rating that will meet or exceed your requirements. RC is the number of minutes a fully charged battery at 80 degrees F is discharged at 25 amps before the voltage falls below 10.5

Hope this helps!

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'99 S420 - Mommies
'72 280SE 4.5 - looking to breathe life into it
'84 300SD Grey - Sold
'85 300SD Silver - Sold
'78 Ski Nautique

The hated Exide battery has done that to me with both of my of my MB's. I had a series of them replaced under warranty until the last one finally lasted beyond that cheap warranty.
There is a very easy way to test for the most common failure on the Exide. That being a dead short is one of plates.
The quickest way to check that is to pull the caps and dead short the positive and negative terminals. If there is a short that cell will erupt like a geyser.
The test is reliable, but not entirely safe. You would need safety goggles and gloves and get the battery away from anything you would not want to have contaminated with battery acid.
Personally I would just look at the name on the front and condemn it. Get a Johnson Controls at Walmart, of an Interstate. I have one of each now. Do far they both have lasted over two months. That is at least twice as long as the Exides averaged.

AutoZone has a MB type 49 battery with a 7 year warranty supposedly made by Johnson Controls for $60. Warranty based on selling price not some fictitous "list" price. That's less than $10 a year.

Warranty done by their computer so if you lose papers warranty is still honored not like Pep Boys where no papers: no warranty.

Walmart doesn't sell Group 49 batteries anymore.

P E H

Get Sears Die-Hard International



David

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1985 300D Turbo

The new Die Hard group 49 batteries are supposed to be good, the older ones are crap. The first one I got was bad, and now that I am on my second battery. So far this battery has been doing good, but I have a feeling that it is about to give out.

drawde;
Sorry about the dead battery. Just a reminder to have CLEAN terminals at BOTH the battery and at the STARTER and at the ground strap from the transmission/ engine to the chassis.

I, too have heard the dreaded EXIDE stories. Don't know if the are valid or not.

I, do know that PEH is on to something with the autozone units. Reasonable price/ powerful cold cranking amps, and the warrenty. Always take the warrenty with a grain of salt. Depends on the store manager. ie; when I went to return my 2.5 year old battery to them during the terrible cold last december, I was told that the battery was still GOOD. I knew this to be true for the most part. HOWEVER, I drive a DIESEL and would not take no for an answer! After bit*hing with th store manager over and over for 20 minutes....I asked to speak with the regional manager and was put onto the phone with him. This process lasted for another 10 minutes of I drive a DIESEL and need every last bit of juice that I can get. I took the battery out in the bitter cold on the street and I was not going to put the old one back in. SYNTHETIC OIL would have been a BIG help.

Also, if I had BOTHERED to actually plug the block heater in for 2 hours, I would have not had to have been such an a**hole.

THE CUSTOMER IS ALWAYS RIGHT! The store manager was sure supprised when I gave him back the phone and then he had tha counter guy get me a BRAND NEW BATTERY.
Do you folks out there believe that I should have returned with a case of beer for them at the end of the day?

Probably.

I do think that the INTERSTATE is probably a bettey battery tho .

Best wishes always, and keep those diesels humming!
Spo out.

I replaced a two and one year old Interstate this fall with an Auto Zone battery. I've had great luck with the Auto Zone units. The Interstate just would not turn the car over fast enough to start easily. Now the car starts great.

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Mike

2000 SL500 22,000 miles
1981 300CD 188,000 miles
1979 450 SEL 266,000 miles
2005 Cadillac CTS 25,000 miles

A couple of years back I changed out my boat batteries with gel cells and have had great results (retains charge longer, no need to check electrolyte level, no plates to deteriorate). I was wondering if anyone has used a gel cell battery for their diesel? If so what was/is your experience?