Bad (Optima) Battery ??

[Mike Braddock]

This afternoon I finally got up the nerve to try and crank the sleeping beauty...but to no avail . Checked timing, set the fuel pressure, primed the engine, topped off the coolant, etc. And then...BOOM.

Just kidding! Actually, there was no boom, and there's the rub . I couldn't get it to fire off. Played with the timing a little and it had no effect. Looked down at my voltage gage and it measured about 11-1/2 volts...hmmm. That can't be good I thought to myself

So I hit the cutoff switch and measured the voltage on the battery voltage. 11-1/2 V again. Hmmm...now I start to worry. So I threw the charger on it for a while and it brought the battery voltage up to 12.4 V. Then I put a battery load tester on it and that pulled it right back back down to 11.5 V or so..uh oh..I think to myself .

Funny thing is it turned the engine over with no problems. I cranked on it for a total of about 5 minutes this afternoon and it the engine never slowed down. So on the up side, my engine and starter grounds must be good . hehe..

If I recall correctly, these batteries are made up of a dozen 1.2V cells. Is this correct. So, I should have terminal voltage of around 13.8 - 14.4 volts normally? The battery, as indicated in the thread title is an Optima that I purchased from Summit about 2 years ago and (unfortunately ) it has sat on the shelf or in the car ever since.

Am I correct in deducing my battery is BONED?

Has anyone had a similar problem with Optima batteries. (Okay, okay, no funny comments about how no one else's build has taken 2+ years !)

Would this explain why I couldn't get the engine to fire. I only had 11.5V to the MSD, which I suspect is not enough (?).

Thanks so much for your help!

Mike

[bran3b]

Mike,
Have you checked for spark from the coil? I have killed 2 MSD coils by not having adaquate chassis grounds. I am also using an Optima battery and MSD ignition. I also fried an MSD Ignition module, also with a bad ground. Try checking the ignition before you buy another battery. If you search for threads that I started (asking for ignition help I think), you will find some very helpfull tests for MSD ignitions.

Bran

[Mike Braddock]

Thanks Bran. I'll look at your old posts...

Mike

[JimsGems]

Batteries are funny things, as you know. If you charged the battery and you were able to load test it accurately and it's pulling down to 11.5 when 13.8 to 14.4 optimal you are loosing to a 2.3v drop under load, I’d say… "your battery is toast!"

I manage Uninterruptible Power Systems (UPS’s) with 600 batteries (typical per location) including distribution and related inverters and I loose approximately 8% (48 batteries) a year on average, and they are under constant load. Batteries used or unused fail! (These batteries are about $600 each) The new batteries (Gel-Cells, like the Optima requires no maintenance once activated) are much better and more stable than lead-acid batteries of the past.

Once activated you can plan on a four year life cycle (under use or sitting on a shelf), batteries will usually work better if they are used and prevented from being "deep cycling" (run down and fully recharged). There are trickle chargers designed and available, I strongly suggest once you install a battery in a Cobra or…? And it may sit through a winter or during a two year build, keeping a trickle charge on the battery will assure a good chance to get optimum life out of your battery.

Batteries also like moderate temperatures without getting real cold or real hot, that another reason to keep the battery behind a seat or in the trunk. Ideal (I said Ideal) is 68 to 74 degrees. Cold batteries can’t make enough power and hot batteries have a shorter life cycle. Don’t let batteries freeze and don’t set or store them on a concrete floor. This is just a basic rule & there are always exceptions.

[petek]

Mike,
Jim has nailed it, the battery is probably toast. I've had my optima battery for at least 4 years, but I charge it regularly and the battery seems fine still (I'll know for sure in a month or so when my Cobra is on the road).

Given the spiral construction of the plates in the Optima you might be able to knock some of the sulfation off of some of the plate surface by charging the battery for a couple of days. Perhaps the heat generated will push the sulfation into solution.

Mind you ... it's a BIG might / maybe / perhaps.

[427sharpe]

WHOA THERE KIDS! If a battery cranked a motor for 5 mins at normal speed the battery is fine! The battery DOES NOT make the engine fire, it merely turns it over to start the combustion process! If a motor is turning over at correct speed but NOT FIRING, than something in the IGNITION circuit is at fault. 3 things make a motor work; air, fuel and spark. NONE OF THEM ARE BATTERY RELATED!!! The battery is a reserve power source to TURN the motor over, NOT TO RUN IT!! Check the 3 things in the reverse of the order above to find a problem! Pull one plug wire and check for spark...is it 'hot' (deep blue and strong) or is it weak? If you have NO fire at the plugs, ck for fire at the coil. None there, ck for 12v INPUT from the ignition circuit. Nothing? Bad ignition switch probably. If you ARE getting spark, ck fuel delivery...you may have a clogged fuel filter. In any event, IF THE MOTOR IS TURNING OVER AT NORMAL SPEED THE BATTERY IS FINE!!!!! I can't tell you how many customers have come into my shop for batteries because a car wont FIRE and get p/o'd because their diagnostics were faulty! If the motor has been sitting for awhile, you may ck compression..you might have lost ring seal..if compression is down squirt a LITTLE Marvel Mystery Oil in the cylinders, wait about 10 mins and fire it up. Sorry to rant, but this is a sore topic in the automotive business!

[Mike Braddock]

Thanks for all the informative posts guys! Good info Jim. I realize now that I should have put a trickle charger on it, but I didn't think about it then. I will do so in the future.

In the Summit catalog the advertise these batteries as having a two year shelf life, and this one's been sitting for about 16 months. I plan to call Summit on Monday to see if they'll make good on it.

Sharpe, despite the fact the battery turns the engine over with no problems (I did put a little marvel mystery oil in all the cylinders), there seems to be a definite problem since my battery voltage is measuring between 11.5 and 12.4 V. Isn't 11.5 V low for a load test? My tested indicated the battery was weak or dying (now there's a useful diagnosis ) Your points are well noted. I have fuel and need to check spark (although it was firing and would run for a very short time after I left on charge for about an hour this evening). I am going to trickle charge the battery over night and check it again in the morning. But...I think it's toast. Pete, I'll let you know if the slow charge happens to knock off some of the sulfation, as you noted. I realize it's a long shot...

Thanks again for all of you ideas and opinions. I'll post back when I know more. I wish you all a wonderful weekend!

Mike

[petek]

Mike,

If you've got one of those automatic chargers then use the higher charging rate and let the charger set it self down to a lower rate. The higher rate may do the trick, but don't leave the charger connected if the charger isn't one of the automatic types.

However... 427sharpe is correct in noting that if the battery was strong enough to turn the motor over for 5 minutes (!) then the battery is probably pretty darn good! Are you sure your voltmeter is correct? You're not using the dash voltmeter are you?

Hey, I found the specs for the starter on my Cobra. Max power current is 349A. Free running, 52A. Ok, let's call it 350A while turning over the motor. That's 350A for 5 minutes! I'd say the battery was doing the level best that it could.

How old is the gas in the tank?

[Cobra20646]

Mike,

Listen to both 427 sharp and petek. I agree with them 100 percent........ if you cranked that long on the starter and still maintained 11.5 volts, that battery is doing OK. Even if the terminal voltage is down to 11.5, that is still sufficent to start and run the car. You might have lost one cell in the thing, but the remaining cells are up to the chore. At this stage of the game, you can plan on replacing the battery some day, but this battery is not going to make any difference in your "start and run" problem today.

[Mike Braddock]

I'm going to check the timing to make sure i don't have the distributor in 180 degrees out and pull a plug and check for spark as Sharpe has suggested. The fuel is only a few days old, so I don't think that's a problem. My charger does taper off, so I'll keep in on charge while I'm working on the car today and see what I can do. Thanks again for all of your help!

Mike

[427sharpe]

If youre gonna pull the distributor, be sure to ck the roll pin and make sure that it hasn't broken, which would allow the gear to rotate around the shaft. Why do you think you timing has gone 180 off since you last drove the car if it has been idle????

[Mike Braddock]

Sharpe,

We've yanked the distributor a few times to pull the intake, prime the engine, etc. I was certain I timed it correctly but something is wrong I'm out of town for a week, so I'll post back when I can try this. Thanks again!

Mike

[chopper]

For my 2 cents worth, I'd have to agree with 427Sharpe and Cobra 20646. If the battery smoothly turned the engine over for 5 minutes (or even two minutes, for that matter), the problem was not the battery. The battery supplies the power necessary to turn the engine over, and also the power for operating the ignition until the alternator is spinning at sufficient speed to supply the required current at the proper voltage. (That is why the alternator is designed to generate 14 to 14.4 volts while the battery is usually around 12 to 12.4; the electrical power for normal operation will then be supplied by the higher voltage alternator rather than the battery.) Most starters are capable of spinning the engine at approximately 250-300 rpm maximum. At this engine speed, the alternator is normally not generating voltage equal to that being supplied by the battery, so the battery is still providing power to the ignition until the engine starts and comes up to at least idle speed. However, if I remember correctly, the MSD system should be capable of operating at voltage levels down to about 9 volts. My MSD 7AL system has started my engine when the old battery was so low the starter would stop momentarily between engine revolutions. If your battery is spinning the engine correctly and you still have 11.5 volts at the terminal during the starter operations, the problem is most likely not the battery.

The 12-volt automotive battery itself is made of six, 2.0 to 2.1 volt cells, connected in series. There is some small voltage drop across the connectors, so the total voltage across the terminals should work out to (6 X 2.1) minus the cell connection voltage drop to equal the 12 to 12.4 volts commonly seen at the terminals. Also, most automotive batteries are designed for high-amperage, short duration power surges. If you look at your Optima literature, or go to their site, they state that the starting batteries are designed for putting out maximum amperage for 5-second durations, as is typical during starting sequences. Most automotive batteries only use about 3-5% of their capacity during a starting sequence. They are not really designed for "deep cycle" discharging such as is seen in batteries used for golf carts and trolling motors; that's why battery makers produce "deep cycle" batteries with different dimension to the internal lead plates. Deeply discharging a starting battery will usually have some small penalty in battery life expectancy. That is not to say it will suddenly fail (although, like any battery, it may for a variety of reasons) but rather you may have to replace the battery a month sooner than you would have had to otherwise.

If I may make one suggestion: Check the MSD website www.msdignitions.com and look under their troubleshooting guide. They have some quick checks to go through to determine if their system is bad. If you still suspect that the ignition is ka-ka, get in touch with them via e-mail. I have personally worked with them on problems with one of their components and found them to be extremely helpful and professional, and they corrected my problem in a fair and responsible manner. Good luck.

[SGBoulay]

The battery is not the problem, probably not the timing either. How about checking for spark. You need air, fuel and spark. Anormal battery should have a voltage of 9.6 v or higher after a 15 second load test. Your battery is great.
bill

[cliff1963]

Mike,
I have been there. Read your trouble shooting page for your MSD box, it requires a minimum 12.5 volts to fire. That is your problem. The battery is toast if it will not hold voltage under load.

[427sharpe]

Yes, the MSD requires 12.5 volts to fire..and fire volts are supplied by the alternator, not the battery. I run MSD (the old Ford SVO stand alone ignition) and I know that NO battery will hold 12.5 volts under a load test! It's optimum charge is 12.75-12.5 volts, which means that it would have no voltage drop under load! A battery will regularly drop below 11 volts with a severe draw, and still start a car! I really believe that the problem presented here is either fuel or ignition related. I would lean toward a fuel problem as the first thing to check, just because it's the easiest!

[Cobra20646]

Well... I see we have some differing opinions of the state of this battery.

For openers, 427sharp is correct that no battery will have ZERO voltage drop under the load of the starter. I read somewhere that a good battery will drop to about 9.5 to 10.5 volts under normal conditions. If it goes below nine volts, then it considered time for replacement.

Second, the alternator will NOT come into play until the engine is running and turning enough revs to get the alternator to put out a "charging" voltage. (Alternator has to supply more voltage than the terminal voltage at the battery)

So..... if the MSD requires 12.5 volts to work, how does it start the car? My guess is that it will supply a spark.... enough to start the car...... but not at a level that it can output if supplied by 12.5 volts or greater.

If the MSD troubleshooting manual says that it needs 12.5 volts to work (and will not work AT ALL at 12.4 volts or below ) then give me back my simple mechanical points and coil.

I still say the problem is elsewhere and not related to this battery.

- Jim -

[petek]

Any battery will exhibit a voltage drop when a load is placed on the battery. The drop is due to the internal resistance of the battery (with respect to the load). I wouldn't be suprized to see a two volt drop on a lead-acid battery when you place a 300+ Amp load (starter). Even though a lead-acid battery has plates with fairly significant resistance (i.e. lead), due to the surface area of the plates the total internal resistance of a lead-acid car battery is quite low and that's why we can get 300+ Amps from the battery.

I would guess that the efficiency of the MSD ignition may be lower at lower voltages. Continuing to guess; there may be certain functionalities within the MSD unit that would not function at lower voltages. I would be very surprized, however, to learn that the MSD unit would not produce a spark at voltages as low as 10 volts.

If the MSD unit would not function at lower voltages you'd never be able to start your car when the air temperature dropped as the voltage on the car battery also drops with respect to temperature.

[Mike Braddock]

Well, I'm back in town but I've got another minor setback . My fuel tank has a small pinhole in the bottom that is leaking, so I yanked the tank and took it down to my local radiator shop to have a liner installed that will fix the leak(s). It should be ready to be picked up this Friday, so I should be able to get back on track shortly. Thanks again for all of your replies. I'll post back here on Saturday night regardless of what happens.

Mike

[427sharpe]

AHA MR Watson! A new part to the puzzle! Are you using a steel gas tank?? If you have a pinhole in the bottom and no dent outside, it is rusting inside. Rust that got sucked into your fuel system and may have eaten your fuel pump and/or clogged your fuel filter.........you may have found your problem! While you have your tank out, check the fuel pump for flow, and replace the filter no matter what. You can flush the lines with an aerosol can of carb cleaner and an air compressor...just flush the LINES, not the carb or fi unit! This one has me intrigued, so be sure to post what happens!