How To Test A Car Battery

Owning a vehicle in this day and age is a real necessity. Without one, you’re going to have a terrible time attempting to get from one point to another. Unfortunately, owning a vehicle is not all fun and games. You are going to be responsible for caring for each and every aspect of the automobile. Suffice to say, you’ll need to make sure that the car has a fresh battery. Learning how to test a car battery is in your best interest. You’ll learn how to do just that in the guide below.  

  What You May Need  

  Before you can determine whether or not the battery is dead, you’re going to need certain tools. Don’t worry. The required equipment is not expensive in the least. You will either need a digital multimeter or a hydrometer. A hydrometer will provide you with more in-depth details about the battery. While the digital multimeter can only determine the current charge of the battery. The hydrometer will tell you that as well as the battery’s overall health. Again, both items can be purchased pretty cheaply. Visit your local hardware or auto parts store to buy one today. 

Warning Signs Of A Bad Battery 

  If you are not savvy about car maintenance, it is highly likely that you will not know if your battery is failing, before it finally goes kaput. Once the battery reaches this point, it will no longer be able to power the starter motor, resulting in the car not starting. This issue could leave you stranded in an unsafe location. The only way to prevent this from happening is to know the warning signs of a bad battery.   

 · Headlights dimming during operation 

· Vehicle backfiring 

· Slow engine crank 

· Electrical components not working properly 

· Swollen battery case 

· Rotten egg smell under the hood  

  Knowing these signs in advance will give you enough time to replace the battery, before it completely malfunctions.   

   Testing The Battery With A Hydrometer  

With a hydrometer, you’ll be able to test the battery pretty easily. When testing in this manner, you’re going to be performing an electrolyte gravity test. This type of test can help you find out whether the battery is fully charged, faulty or undercharged. It will provide you with more detailed results than a multimeter. Just remember to use a hydrometer that is equipped with a built-in thermometer. This type of hydrometer will deliver the best results. Also, be sure to wear acid resistant goggles and gloves when carrying out the test.  

  1. First and foremost, you will need to remove the caps from the battery. 

2. The tip of the hydrometer should be inserted into the tip of the first cell. Gently squeeze the bulb. 

3. Once you’ve released the bulb, electrolyte will be suctioned into the needle of the hydrometer. 

4. Now, you will be able to analyze the electrolyte specific gravity. You may need to refer to the included instructions. 

5. Write down the reading and continue with the rest of the cells. 6. Analyze the results and compare them to the included instructions.  

While it may vary depending on the specific tool that you’re using, a fully charged battery will have a reading between 1.265 and 1.299. If the rating falls below the 1.265 mark, you are dealing with an undercharged battery. You can most likely recharge the battery and make it functional again. If you have a difference of 25 to 50 between the various cells, you will most likely need to replace the battery completely.  

  How Many Volts Will A Fully Charged Battery Have?  

It is true that car batteries are rated at twelve volts DC. However, most car owners are shocked to learn that batteries actually harness more power volts than this. In fact, it takes right around 12.6 volts or more to start the vehicle and that is what a fully charged battery should read when the car is off. Simply place the black lead from your multi meter to the negative terminal on the battery and place the red lead of the multi meter on the positive terminal of the battery. When the car is off the readout on the screen should be 12.6 volts or more. When the car is running you will probably get a reading of anywhere from 13.7 to 14.7 volts. These readings will indicate that you are dealing with a fully charged battery.  

  Quick Check Without Any Special Tools  

 It is possible to check your battery without the use of any special tools. You can do this by simply starting up the vehicle and turning on the headlights. If the headlights appear dim, this means that the lights are running off the battery and the charge is low. This could be an indication that the alternator isn’t producing enough of a charge. If the lights are dim, you can also try revving the engine. When revving the engine if the lights get brighter, it means that the alternator is producing some charge, but not enough in idle to keep the battery fully charged. If you rev the engine and the lights maintain a normal brightness level, this is probably a good indication that the charging system in functioning properly. 

Visual Inspection 

Sometimes, you just need to give the battery a good visual inspection to find out what is wrong. Below, you’ll find out exactly how to inspect the battery case and cables to see whether or not anything has gone awry. 

1. Before doing anything, you should disconnect the cables. Remember to start with the ground and then remove the position. After that, you should remove the battery’s hold-down mechanism. 

2. Inspect the hold-down mechanism to ensure that everything works. Replace hardware as necessary to ensure that the battery doesn’t bounce around when the vehicle is driven. 

3. Remove the battery and place it on a level surface. Make sure that the case does not have any cracks. If you identify damage, the battery should be replaced. 

4. Look for indications of bulging. This can indicate a problem with the charging system. 

5. Finally, look at the cables carefully. Do you notice any cracks or frays? If so, the battery cables must be replaced right away.   

  Take these steps to identify any potential problems. If you notice anything out of the ordinary, you should fix it immediately. Otherwise, you may cause additional damage to the vehicle, battery or cables.