Was starting like a champ down to 0. I left my lights on maybe two weeks jump started via extra battery. Changed a tail light. went to start last week, pretty warm about 30 degrees and in a garage, and it cranked like it was -10. I thought dirty terminals, so I lightly filed off corrosion on terminals and clamps. Same deal. Battery voltage 12.5 with car off. Glowplugs all test good for continuity. I'm reading now, check ground strap. Other than that, where do I start?

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1981 300D 205,000 mi.

I'd get the battery load tested. Sounds like a bad battery to me. Depending on how old the battery is, I might just purchase a new one.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

You only get to leave your lights on for two weeks..........once.

Then you purchase a new battery.

Ha ha, the lights weren't on for two weeks (my typo), but I get what you are saying. (The battery is old as well, new battery time.)

What is it that makes battery 'load' go 'bad'? I've never heard that term though it makes sense. I've always just thought, if you are getting more than 12 you are gold. volts like horsepower, load like torque?

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1981 300D 205,000 mi.

The lead acidic batteries used in cars do not like to be deep discharged. If I remember right it creates a sulfite layer on the plates that kills the battery. How long did you run the car after the jump? Did you go for a long high speed drive? MB alternators (in my experience) take a long time to recharge a discharged battery. The charge output is a little low at low speed and idle, but good enough to keep your battery charged under normal conditions.

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1982 300SD 180K, rebuilt engine
1973 450SLC Megasquirt
1990 Volvo 780 - 273k
1993 Volvo 240 Wagon - Scrap yard slumber

http://www.fuelly.com/sig-us/44619.png

12.6 or above,typically around 12.8 is the normal reading of a fully charged battery.

12.5 may well just kick the engine into life if it was not a diesel,the glow plugs rob a fair amount of power.

12.0 is near enough flat,it will run a headlight or two but the starter will just click

It's a combination of sulfation on the internal plates , a normal thing that gets worse and worse as time goes by .

And , the normal accumulation of debris in the bottom of the battery eventually builds up and touches the bottom edges of the plates causing an instant short in that particular cell .

Last summer I had two batteries that were fine until they simply couldn't start the car .

I was on vacation far from home in the 240D when this happened , 120* F heat too .

Wall-Mart had the best and cheapest battery for what that's worth . Auto Zone had the wrong BCI Group one , it was only 850 CCA too - yet they insisted it'd be fine even though the hold down wouldn't hold it and yes , battery hold downs are critical to get long life as vibration is the # 2 killer of vehicle batteries .

If you have a voltimiter , read the cranking voltage , it should stay above 10 VDC when cranking .

Once in a while the BOSCH starters just need new brushes , cleaning and of course, a dab of good grease in the commutator end bushing to return them to zippy cranking speeds .

This is a simple DIY job , if you ruin it no worries , just re-assemble and exchange it .

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

Check the level of the fluid in each cell of the battery. Use ONLY De-Ionised water to top up. Tap-Water, Evian etc, Will Kill It!

Try a nice, long slow trickle-charge at an amp or two for a day, this can remove some sulphate if its built up--Depends on just how bad its got. If it still doent perform, looks like it may well be past its best.

Its not only Sulphation that kills batts. The Pos. Plates inside over years, corrode away, buckle and crack-up, increaing the 'Internal resistance' so the batt will no longer supply its full rated Current....

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http://i190.photobucket.com/albums/z...0TDnoplate.jpg

Alastair AKA H.C.II South Wales, U.K. based member

W123, 1985 300TD Wagon, 256K,
-Most recent M.B. purchase, Cost-a-plenty, Gulps BioDiesel extravagantly, and I love it like an old dog.

W114, 1975 280E Custard Yellow,
-Great above decks needs chassis welding--Really will do it this year....

Forget that thought.

Yeah I drove it for about 1.5 hours on the highway afterwards.


Excellent information here fellas. Thanks! I didn't know that about the vibration thing either. Or that the voltage difference allowed was so small... 12.5 might go, 12.3 good luck, 12 no way. I looked on the Excellent information here fellas. Thanks! I didn't know that about the vibration thing either. Or that the voltage difference allowed was so small... 12.5 might go, 12.3 good luck, 12 no way. I looked on the Excellent information here fellas. Thanks! I didn't know that about the vibration thing either. Or that the voltage difference allowed was so small... 12.5 might go, 12.3 good luck, 12 no way. I looked on the Excellent information here fellas. Thanks! I didn't know that about the vibration thing either. Or that the voltage difference allowed was so small... 12.5 might go, 12.3 good luck, 12 no way. I looked on the autozone site and they have a 1000 amp one (49-DL) I might just go and pickup. I'm not sure what 'the wrong BCI number' is however.

So I'm assuming you don't ahve to remove the whole start to grease that part? I heard replacing the starter is a pain, if I'm taking it out a new one is going in.

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1981 300D 205,000 mi.

Hi
Deep discharge can wipe out an old battery - as can fast charging one that is discharged.

Best course of action is to hook up a charger for 2 amps for 24 hours and/or until the charger indicated that the battery is charged.

You can pop the tops off and check how each cell is bubbling - when the battery is charged - all the cells should bubble at about the same rate.
Do no connect or disconnect the charger leads (or make any other spark)while the caps are off - the bubbles are hydrogen gas which is highly explosive. if some of the cells are low on electolyte, disstilled water should be added. A better test is to use a hydrometer to check the specific gravity of each cell - the s.g. should be close to same all across the cells.

The final test once the battery has been charged is to load test to see how many amps it will deliver for 10 or 15 seconds. Or if the other tests look good - just use it to try to start the car.

I just bought a group 49 MAXX battery from Wal-Mart for $75 - the best deal I could find.

Good Luck, Joseph

woo---eee well that solved it. New battery, cranked like she should. I did notice on putting the new one in that about 8 of the wires that make up the negative cable are split. I'll be getting a new one of those too. Would that have an effect on it as well?

I live in Chicago, and am renting a garage for $60 so it would stay warm enough. It worked, but I didn't think about using that money to wire a second battery instead.

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1981 300D 205,000 mi.

Using a cheap cigarette lighter voltmeter can help keep track of the condition of the battery by telling you the at rest voltage and voltage under load. They only cost about $8.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

my dual battery install cost about $80, but i got the battery for free.

double that if you don't have another battery already.

i think the difference is definitely worth it.

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1981 300 SD 213k miles "Stock for now"
1999 Super Duty 7.3L 113k miles
1981 300 SD 180k miles "Heavily modified" SOLD

I have a garage this winter, so I probably wouldn't try it until next. I'll read up more about it, I think I read some discussion about wanting the smae battery to avoid one leaking charge to the either , perhaps a s hiny new alternator since it would have more to charge. Anyways, until then... thanks guys! It is a joy to hear that thing fire off, it was definiately a year over due.

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1981 300D 205,000 mi.