You guys know the issue's I've been working through with hard starting on my 2002 7.3 A while back I took my batteries to Autozone and had them check them. They said they were fine but because of my hard/no start situation cranking on it for a short time (couple of minutes) kills the battery. The transmission shop said that they had to charge it after sitting for a couple of days to get it started. I have a multi-meter and know how to check the voltage. I even have AE and it gives me the voltage. Are there any other tools or procedures to check the health of the batteries?

 

You need a load tester. They are pricey, but they are a very good tool to own!


http://m.ebay.com/sch/i.html?_nkw=load+tester

 

As Mike stated above, you need a load tester to properly test the condition of your batteries. Even if a multi meter displays correct voltage, it doesn't necessarily mean your batteries are strong enough to crank with a load on them. Also, disconnect your cables to make sure you're testing them individually.

 

What is mentioned above is correct. The voltage can seem good when the battery is just sat there, but as soon as you apply a load the voltage can tank. Placing a load on the battery is the only way to really see what it is doing.

Another way to maybe accomplish this is to watch the voltage while trying to crank the engine, if it starts tanking then it would start pointing to an issue.

 

You CAN tell an awful lot about a battery state of charge, with experience. You can also glean useful info by monitoring battery voltage during cranking. Sort of a "poor man's" load test.

http://www.batteryfaq.org

Has the charts and charging algorythms and temperature compensation tables, etc. Notice a fully charged "maintenance free" battery is 12.8 volts (surface charge removed), a standard lead-acid is 12.6; this doesn't sound like much - 0.2 volts, but consider the difference between 100% and Dead In The Water - is less than a single volt. Tenths are important.

In your case all things being equal I'd purchase a good charger before a load tester, and maybe some cables. Once a battery (cell really) becomes mismatched or discharged as part of a larger bank they need some serious juice to get back on the same page.

 

BATTERY TESTING:


There are several different Tools which will provide the same overall information if used correctly. i.e.: DVOM, Carbon Pile Tester or Similar Device, Hydrometer, High-Voltage-Clamp (800+ AMPS), Automotive Logic Probe, T-Pins.

Battery testing has changed in recent years; although the three areas are basically the same, the equipment has improved.

1. Visual Inspection

2. State of Charge & Specific Gravity

VISUAL INSPECTION

Battery service should begin with a thorough visual inspection. This inspection may reveal simple, easily corrected problems.

1. Check for cracks in the battery case and broken terminals. Either may allow electrolyte leakage, which requires battery replacement.

2. Check for cracked or broken cables or connections. Replace, as needed.

3. Check for corrosion on terminals and dirt or acid on the case top. Clean the terminals and case top with a mixture of water and baking soda. A battery wire brush tool is needed for heavy corrosion on the terminals.

4. Check for a loose battery hold-down or loose cable connections. Clean and tighten, as needed.

5. Check the electrolyte fluid level. The level can be viewed through the translucent plastic case or by removing the vent caps and looking directly into each cell. The proper level is 1/2" above the separators (about 1/8" below the fill ring shown below). Add distilled water if necessary. Do not overfill.

6. Check for cloudy or discolored electrolyte caused by overcharging or vibration. This could cause high self-discharge. Correct the cause and replace the battery.

STATE OF CHARGE

The state of charge of a battery can be easily check in one of two ways:

Specific Gravity Test Open Circuit Voltage Test
Note: A state of charge test is required to determine if there is sufficient charge in the battery to properly perform a capacity test (explained later). The only exception to this is the MIDTRONICS Battery Tester. This new state of the art capacitance tester will be discussed later in this module.

SPECIFIC GRAVITY - The "Real" Story

Specific gravity means exact weight. A "Hydrometer" or a "Refractometer" compares the exact weight of electrolyte with that of water. Strong electrolyte in a charged battery is heavier than weak electrolyte in a discharged battery. By weight, the electrolyte in a fully charged battery is about 36% acid and 64% water. The specific gravity of water is 1.000. The acid is 1.835 times heavier than water, so its specific gravity is 1.835. The electrolyte mixture of water and acid has a specific gravity of 1.270, usually stated as "twelve and seventy."

SPECIFIC GRAVITY READINGS

By measuring the specific gravity of the electrolyte, you can tell if the battery is fully charged, requires charging, or must be replaced. It can tell you if the battery is sufficiently charged for a capacity (heavy-load) test. The battery must be at least 75% charged to perform a heavy load test. (The heavy load test will be discussed later). In other words, each cell must have a specific gravity of 1.230 or higher to proceed.

CELL %CHARGED

1.270 100%
1.230 75%
1.190 50%
1.145 25%
1.100 0%

If the battery is less than 75% charged, it must be fully recharged before proceeding. If the battery is 75% or higher proceed to a heavy load test. A battery not sufficiently charged will fail because it is discharged.

SPECIFIC GRAVITY - EXCESSIVE CELL VARIATION READINGS

Variation in specific gravity among cells cannot vary more than 0.050. The variance is the difference between the lowest cell and the highest cell. A battery must be condemned for excessive cell variation if more than 0.050. In the example below, the highest SG reading is cell #1 (shown in green) while the lowest SG reading is cell #5 (shown in blue); the difference is 0.070 which requires battery replacement. Cell #5 if failing.

Cell #1 Cell #2 Cell #3 Cell #4 Cell #5 Cell #6
1.260 1.230 1.240 1.220 1.190 1.250

Many factors contribute to cell variation; for example, if water was just added to that cell, the cell is then diluted with water resulting is a lower specific gravity reading. Recharging the battery would correct this false reading. In some cases if a battery that has cell variation slightly over the specification and is only about 50% charge, charging the battery at a slow rate of charge (5A) may reduce the cell variation, thus saving the battery.
SPECIFIC GRAVITY TEST PROCEDURE (HYDROMETER)

1. Wear suitable eye protection.

2. Remove vent caps or covers from the battery cells.

3. Squeeze the hydrometer bulb and insert the pickup tube into the cell closest to the battery’s positive (+) terminal.

4. Slowly release the bulb to draw in only enough electrolyte to cause the float to rise. Do not remove the tube from the cell.

5. Read the specific gravity indicated on the float. Be sure the float is drifting free, not in contact with the sides of top of the barrel. Bend down to read the hydrometer at eye level. Disregard the slight curvature of liquid on the float.

6. Record your readings and repeat the procedure for the remaining cells.

ADJUSTED SPECIFIC GRAVITY READINGS

Temperature correction is needed because specific gravity changes with temperature. Cold thickens the electrolyte and raises the specific gravity. Heat is the enemy. It thins the electrolyte and lowers the specific gravity. Hydrometers are calibrated at 80'F (26.7'C). Electrolyte temperatures above or below 80'F must be adjusted. For every 10'F increment below 80'F, subtract 0.004 to the hydrometer readings, and for each 10'F increment above 80'F, add 0.004 to the readings. See the examples below.


Doing a Simple Voltage Drop using a DVOM when known variables such as starter, alternator, health are known. Merely measuring each cells Voltage will identify shortcomings as well.

 

I was going under the impression that the OP didn't have access to an internal resistance tester, hydrometer or any other specialized equipment. A DVOM is a useful tool to have anyway so at least he wouldn't be buying equipment for a (potential) single issue. Sure it's nice to have or at least access to all these things, but is it necessary, given the price to buy all this stuff? Not necessarily.

 

The conductance testers are slick, they use an AC signal derived from the battery voltage itself to perform the test ie., they are self powered.

They don't necessarily require the battery to be at 100% state of charge to perform a test making them convenient and easy to use. They require a minimum of 8 or 9 volts. This makes them desirable for a fast decision. If for some reason one had a pile of batteries for triage they'd be great or shopping for (and rejecting) new batts. Also would be wise to check any battery before playing the Good Samaritan and jump starting a battery for someone in need.

For a truly valid, old-school load test though the battery must be charged, and would also need re-charging after the test. This is definitive but also takes more time consequently the conductance testers are popular for battery warranty claims, you can expect to see this type of tester when making an exchange or return.

The downside seems to be, a conductance test that shows a bad battery is definitely defective but the reverse is not always true. I have the lowest rung Midtronics and it works well but then I like gadgets and tools (so sue me) but, an accurate DVOM is more than adequate in the hands of a competent tech. A good sparky armed with even just a test light can do amazing diagnostics. Those inexpensive Innova voltmeters that plug in a power port aka cigar lighter are real handy for monitoring alternator or generator charging voltage on the fly.

 

No, the only equipment I have is a multimeter and a Schumacher SE.6030.

Is this a suitable load tester?

 

100 amp tester isn't good enough, a 500 amp tester would be better


glow plugs will draw about 100 amps, if the voltage drops fast below 12v when GP relay is on then battery is toast


how old are the batteries? I don't usually get more than 5 years use on any battery

 

I'm pretty sure before when I was trying to start it fell below or around 10V and still tried to start it. The batteries work if I charge them and get it running for a couple of days. Sounds like if it sets two or 3 days it won't start without a charge. Might be contributing to my hard start situation, huh! I don't know how old they are...bought the truck used. Here's a probe will it work:

 

Check date codes on batts

 

Only if you want to repair you own vehicle. The savings first hand would pay on the first problem. All could be gotten for under $100 - $150 if you know what you're looking for. And, most have multiple uses.

 

That measures amps only. It does not load test.

If they get drained from a few days the you don't have any reserve left. You could measure the trucks drain but you might find those batteries are toast regardless.

 

I got this one, the price was right and it was real easy to use. I had one battery that was fine and the other failed the load test miserably. Only indication I had was after sitting for a few days the bad battery would pull the good one down and it would crank slow on the first start. After that it would turn over fine until I let it sit for a few days.

Link