Voltage issue?

Hi Guys haven't posted here with a problem in a while but here is something that I've been trying to figure out for a little while.

Over the past couple of years my car has gone through 4 batteries. I thought that it was just the batteries being crappy or undersized (I got an undersized lightweight battery at one point) but now am starting to think that there is something else at play.

A couple of years ago my mechanic did a voltage check and told me everything was checking out good. Since my car is off the road, I've been removing and installing the battery whenever I wish to start it up to run it.

If I leave the battery in the car for a week, even a day- it won't have enough juice to crank the car over. I checked the battery with my multimeter and it read 12.54 volts. I've been keeping it charged on a good trickle charger as well.

Well the other day even that battery couldn't start the car on a full charge. I was like ~~~? and bought a 'normal' battery from Wal-mart. 525 CCA. This battery also shows 12.6 volts.

I pop that Wal-mart battery in and viola' the car starts right up. As soon as I start the car, I go out and check the battery voltage at the battery terminals and I get a reading of 14.30 Volts. According to my Haynes Manual a charging voltage between 14-15 volts is good. I figure I'm good.

I let the car warm up and the fan starts kicking on and off like usual as I'm running it. Now that the car is idling at like 750 RPM, I decided to check voltage at the battery again. This time it was 13.80 Volts.

The fan then kicked on again and voltage dropped to 13.70 Volts. So my questions are: Do I need have bench test my alternator/Regulator here? At fast idle everything seemed ok, but when it warmed up and returned to normal idel, the voltage measured at the battey seemed slightly below spec. Generally speaking it would take a couple of months to Kill a battery maybe that is why I never noticed this or suspected it?
Are there any other electrical tests that I should/could be performing with my multimeter? How does one measure Amp draw with the engine off just in case I have a parasitic drain?

Thanks for any and all help.

Actually, your voltages sound normal. I think the problem is the 525 cca batteries you've been using. They're grossly undersized. You should be using a 800 minimum to 1000 cca battery. The heavy cranking load is what's killing them.

the problem is that the battery goes dead while sitting in the car. you have a parasitic draw. this link gives an ok procedure on how to check for one.

http://flashoffroad.com/electrical/Batteries/BatteryDrain.html

Thanks for the info.

OK so maybe then my Alternator/Regulator is ok so I won't worry yet about removing it to have it tested.

It sounds like I might have a more serious current draw as a possibility.

Mike, from what I'm aware- 525CCA is the stock battery in our cars. At least that is what I remember my Motor craft battery saying. I don't belive my car was optioned up with any "Cold Weather package" which usually specify a higher CCA battery.

The original battery lasted about 8 years so I figured it was ready to go. The other 3 batteries were the lightweight racing batteries. The 1st Dyna-Batt/Odysessy was was most likely undersized at 265CCA but it still started the car down to 20ºF without issue. I traded it back in for a larger Odysesy which delivered 390CCA and that one did pretty good during all seasons.... for about 6 months. Then no matter what the weather- if it sat in the car for a week, it was Ka-Put.

I got a 2nd 390CCA and same deal. Now neither of those batteries will even hold enough of a charge to start the car. Sad that I now have 2 $120.00 paperweights downstairs. So thinking that I had a problem with the car, I bought what I *thought* was a battery at least meeting the minimum specifications for the car so I could continue testing. If I got some kind of 800-1000CCA behemoth, I'm not sure it would be able to fit.... much less do anything for me to loose some LBS from this car.

I'm going to try and check for Parasitic draws. According to that article the other member linked to me, it looks like I put my Multimeter set to 10 DC AMPs and use the negative probe on the positive terminal of the battery after disconnecting the terminal from the car? Do I have that right?

My SC came with a group 65 battery which is about 800 cranking amps. The cold cranking amps would be a lower number. I do get confused between CA and CCA so a 525CCA is stronger that what I was thinking. We don't get much subfreezing weather down here to worry about cold crank amps. I'm running red top Optima's right now. My 89 had a 525 stuck in it that was small and it would barely turn the motor over even on a full charge. My spare battery is 844CA/675CCA groupe 65-1 Silver from Advance. I've also seen some SC's that would crank and crank and not start but attach some jumper cables from another car and it would start up Ok. It appears that these cars need just a little more power to start up than to just turn over due to having to power the electronics.

My SC has a 680 cca Battery in, Thats what it came from ford with,
Deep if you leave a battery on trickle charge for any length of time, you will kill it.
If your battery goes flat after 24 hours, you have a good parasitic draw, Prob Alternator diodes, Mine was the jbl head unit, it wouldn't turn the amp off.

I think your problem is a poor quality connection. A battery should be able to turn over the motor at 10v, thus at 12 volts have no problem.

You should start with checking the quality of the battery connections at the ground, the relay, the starter. Pull them apart, clean them, put them back together. also check for any damage cables.

Then you need to do current draw test when cranking next. I wouldn't use a meter to do that, they make testers for that. Basically you need to measure the current flow between the battery and the starter when cranking. You can ghetto test that by disabling the ignition, and then cranking the motor over for 5 seconds. Then get out and grab hold of the battery cables. they should be warm, but not hot. If they are hot, either the starter is drawing too much current, or the wire to the starter has a poor quality connection. (I had a starter draw so much current it melted the insulation off the battery cables)

Battery voltage should rarely be over 12.5 volts when the engine is off. That is the nominal battery voltage. When the car is on, it should be around 13v when not charging, and can go up to 14.5v when the alternator is in full charge mode.

Once you have the starting problem worked out, then you can check to see if you have a battery drain when everything is off. It is possible for a regulator to fail in a way to draw power when the ignition is off. It's rare, but it can happen.

I didn't think...

That putting a battery on a constant trickle charge would kill it? The battery manufacturers even RECOMMEND keeping them on a trickle charge. Especially if you are storing the car and or not driving it very much.

I'm next to positive my SC came with a 500 something CCA Motorcraft battery. I know that SC's with manual trans had a different spec battery. I think it's a BCI- Group 58 instead of the 65 used in the automatics or SC's with the "cold package".

Mike, thanks for the clarification about the CCA stuff. I was really wondering there for a second

I'm not sure that I'm going to "ghetto test" my battery cables like that but I may just go ahead and try to replace them? Alot of people write that they can internally corrode over the years increasing the resistnace in the cable. This results in a starter mode that draws more of the curent. And, I do/did make sure that the connections at the battery terminals are clean as a whistle.

So basically what you are saying is that when the car's engine is idling 13.8 V on a warm engine is OK?

What about clarification about that parasitic draw test? I'm still not sure hwo to perform it.

cranking amps are measured at 32 degrees F and cold cranking amps are measured at 0 degrees F if i recall correctly...you should be able to find a battery thats a normal size with higher CCA, im using a battery in my truck (83 F150 351W) that has 1000CA and like 875 CCA thats from out TDI bug, and i think its smaller and lighter than my Fleetfarm 600CA battery..one way to tell if the alternators diodes are bad is to pop your hood sometime when the car is cold and feel your alterntor, with the reverse flow it tends to be warm..just a thought, ive used it in the marine field....

-Tony-

PS, anyone care to correct me id be glad to know as i dont want to mis inform

Cold cranking amps measures the amount of energy available to do work at 0 degrees f.
It is the combination of Cold Cranking Amps, and Reserve Capacity that make a battery good for cold winters. You want the proper cold cranking amps for your car, with a high reserve capacity. Often to get the higher reserve capacity you need to get a larger cold cranking amp, as what affects reserve capacity also plays into cold cranking amps.

The reserve capacity tells you for how long you could crank your motor before discharging the battery below a useful voltage.

None of this has anything to do with Deep6's problem.

And yes, the wrong type of trickle charger can damage a battery. There is a chemical reaction that takes place in standard batteries (not optima dry cell type) that causes the migration of materials from one plate to another in the battery. Over time this material builds up reducing the energy available in the battery. The only proper trickle charger I am aware of, is the Battery Tender brand. They use a microprocessor to keep a charge on the battery, without decreasing the life of the battery.

Do you have a battery store chain like "Batteries Plus" around? Most such places will test your charging and battery system for free. They roll a test machine out to your car. pop the hood and test everything.

tight up by the battery doesn't mean tight down by where the cable connects. On the SC, the negative cable goes to the engine block ground at the forward motor mount bolt. The positive cable goes to the relay on the side of the fender. From that relay, a big cable goes down to the starter. The cable going down to the starter has a cable wrapper around it to protect the cable. if your motor mounts go out, its possible for the cable to get crushed and wear through the insulation.

Also if you ever get a new end for a battery terminal, there are new strap type terminals that work well. You don't cut the copper wire on the cable, instead you cut the led off, then drill a hole through the cable and led, and bolt the new end to that. Much more secure connection.

I have one in my car from Wal-Mart that is a 65 Group battery that has something like 1000 CA and 900 or 875 CCA. It's just as powerful as the duralast gold batteries I have used from Auto Zone but just a little cheaper.

Battery Charger

My battery charger is a 7 amp charger from Batterymart.com. I bought it in response to try and keep the Odyssey batteries properly recharged. One battery holds its charge for a few days but the other one overheats and boils the eletrolye when charged. It's recommended for all batteries including dry-cells and starved electrolyte. It has a microprocessor controlled algorithim thing in it so it won't overcharge or undercharge the battery. The charger is sophisitcated enough to "de-sulphite" a battery too.

The new EverLast battery that I picked up from Wally-World is 525 CCA. It's definatly powerful enough to crank the engine over to start it without issue it seems. But I am thinking that I may have old/corroded cables. Since my car killed the other batteries, I'm not taking any chances by leaving this one in the car overnight until I know how to test for everything. Is it easy to change out the cables for new ones?

I may try that "warm alternator" test by leaving the battery hooked up for a while. But I'm still not sure how to execute the parasitic draw test. Anyone else try the test?

While the battery is connected to the charger (and when fully charged) measure the voltage across the terminals. It should be 13.6V. If it's higher, you will kill it over time.

But I'm still not sure how to execute the parasitic draw test. Anyone else try the test?

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Disconnect the {+} cable at the battery, and connect one amp meter lead to the disconnected cable, and the other lead to the {+} battery terminal. Use the 10A function on the meter and read the current draw. If you find you have excessive draw, you can then start pulling fuses and connectors to isolate the circuit(s) causing the draw.

From what I can remember when I tested my own car, I believe it was around 30mA (0.03 amps), that is, after I disconnected the hood light .

Mike8675309 said:

Also if you ever get a new end for a battery terminal, there are new strap type terminals that work well. You don't cut the copper wire on the cable, instead you cut the led off, then drill a hole through the cable and led, and bolt the new end to that. Much more secure connection.

Click to expand...

Where do you find this at?

Auto parts stores have them, lead free connectors.