How to Use A Battery Hydrometer

Car batteries are heavy and mysterious items when it comes to their operations. To many people, the battery either works or fails altogether at some point in time. Understanding how a battery functions and steps to check it are great ways to familiarize yourself with this changing technology. Get familiar with how to use a battery hydrometer for evaluation purposes. These tools can give you more information than just trial and error during charging and discharging.

1. First, Gear Up

Using a hydrometer means that you need access to the sulfuric acid found within the battery. It’s highly corrosive, so be sure to wear the appropriate safety gear.

Put on these items, including:

  • Protective eyewear
  • Thick gloves
  • Closed-toe shoes

Deep Cycle Battery Store¬†even suggests wearing a rubber apron. Any electrolyte solution that’s spilled can quickly burn through cotton clothing.

2. Prep the Car and Battery

Move the car to a well-ventilated area. Shut it off, and pop the hood. Remove the covers on the battery that give you access to the electrolyte solution below, suggests It Still Runs. Because you want to test all of the cells, be sure to carefully take off all of the covers. You don’t want to perform this task midway through your measurement process. Drops of sulfuric acid might spring up from the battery.

3. Insert the Hydrometer

Carefully insert the battery hydrometer into the cell. Press on the bulb that acts as a syringe. You should see fluid filling the hydrometer.

Continue to squeeze the bulb until the battery electrolyte solution fills the device to the maximum level. This device tests each cell by measuring the specific gravity of the fluid. This value tells you if the cell is properly working or on its last legs. Batteries need all six cells in good working order to operate at peak levels, reports How it Works.

4. Read and Test All Cells

With a full bulb of battery electrolyte fluid, read the measured value on the device. Write this value down. Continue onto the next cell. It’s important to take a reading of every cell at the same time before you perform any calculations. The electrolyte temperature plays a role in determining the overall battery life.

5. Calculate Your Results

Make a note of the electrolyte temperature. It’s normally somewhere around 80 degrees Fahrenheit. If the temperature varies, you must account for that change in the calculations.

When you’re measuring the specific gravity, and you read 1.250 as the value, it only retains this number if the temperature is at 80 degrees F. For every 10-degree difference, add or subtract 0.004.

A specific gravity value of 1.250 at 100 degrees F. would be adjusted to 1.258, for instance. The battery life results use the adjusted numbers as follows, including:

  • Between 1.274 and 1.239 is 100- to 75-percent charged
  • Between 1.238 to 1.201 is 74- to 25-percent charged
  • Values under 1.200 indicate a discharged cell

6. Avoid Watering the Battery

There are a lot of tasks associated with battery maintenance, including watering the battery. If you’ve just performed this task, don’t use a hydrometer just yet. Allow it to be discharged and charged back up at least once before measuring the battery electrolyte fluid. You need the water to uniformly mix with the battery’s solution before an accurate number can be measured. All of the cells might test poorly with fresh water in the reservoir.

Discuss your battery questions with our team at Northeast Battery¬†today. Car batteries don’t have to remain a mystery. Learn how to use the hydrometer, and you’ll feel more comfortable around the engine’s components in no time. Being knowledgeable will only help you with vehicle troubleshooting in the future!