Many of the devices we depend on these days rely on internal batteries. From the TV remote to your car, batteries are an integral part of the essentials of modern life. Because there is no avoiding constant contact with batteries, a little bit of understanding can help us to get the most life out of batteries by using them properly for equipment assessment. One of the most important options for improving efficient battery use is a battery tester.
Batteries function by creating an electrical charge through chemical interaction. In most cases, this charge is limited and will decrease over time. Without a battery tester, it is impossible to know how much charge is left. This can lead to anything from simple inconvenience to damage due to misuse. Utilizing a tester will be more important in some situations than others, but it will always be helpful to know exactly what you can expect from your batteries.
Photo Credit: Flickr Bicycle Rikard
The term battery tester refers to a whole range of devices that are used to determine the amount of energy available from a particular battery. There are three basic categories of battery testers:
- load tester
- hydrometer
- voltmeter
Categories of Battery Testers and How They Work
Load testers operate by putting demand on a battery in order to measure the response. This process will take different forms depending on the device and the kind of battery being tested. Commonly used for 6 V, 12 V, and larger batteries, there are also devices designed for smaller batteries.
A hydrometer measures the specific gravity (otherwise referred to as relative density) of liquids. The most common application is when testing automobile batteries. The way these testers work is by estimating the density of the sulphuric acid solution that powers the battery. Battery testers designed for automotive applications generally test specific gravity relative to water at 60 degrees Fahrenheit. Charts must be utilized in order to correct for temperature differences.
A voltmeter measures electrical potential difference between two points in a closed electrical circuit. Available in both analog and digital formats, this is the most common technology for battery testers for smaller-type batteries, though it is often applied for larger battery testing as well. A voltmeter is often built into a device that also measures current and resistance called a multimeter.
Practical Uses for Battery Testers
Starting with the smallest, battery testers are available for AAA, AA, C, D, and 9-volt batteries that are most commonly used for personal devices around the house. These small and inexpensive devices can plug into a wall outlet or can sometimes utilize the energy of the battery being tested and require no external power source. One or more batteries are inserted into slots in the device and the tester will provide a readout. Analog testers use a needle gauge to display results and digital testers use an LED display. For common applications, both devices demonstrate accurate results.
Another kind of battery tester is built right into the battery itself and utilized a special conductive ink. When the two leads of the battery are pressed, a printed gauge on the battery will demonstrate the remaining power supply.
In the case of car battery load testers, there is a little bit more to understand and recommended testers should do the work. Normal car battery testers use a BCI adjustable load test. This process tests the voltage drop when half the rated energy load for that specific battery is applied. In order to achieve accuracy, the person using the device needs to know the specifications of the battery as well as temperature data and input this information into the tester. Moreover, the car battery needs to be at room temperature to insure accuracy and cannot be discharged for proper cross battery assessment.
Another kind of car battery tester utilizes conductance technology. This system tests a battery’s ability to move electrical current. It works by passing a small AC current through the battery to produce a voltage response which is then registered by the tester. This produces the same result as conventional car battery testers though it tends to require less expertise. One advantage of this system is that car batteries can be tested at any temperature and in a discharged state. This is also a good way to accurately determine if a battery is still usable despite corrosion. While the former method requires that the operator be familiar with specific battery characteristics and conditions as well as data analysis techniques, the latter method is much more user friendly.
The new breed of batteries that can be found in high tech gear like cell phones to laptops are referred to as lithium ion batteries. Testing for these high tech batteries has not filtered down to the consumer level for the most part, and it will be difficult to find a battery tester. For now, the best option is to use the batteries as directed and replace them when they no longer hold a charge. In the case of laptop batteries, keeping your computer plugged in as often as possible will extend battery life by reducing use.
It will more important to keep an accurate accounting of battery strength than in others. Around the house, a battery tester is mostly useful for organizing the clutter of new, half-used, and expired AA batteries in the junk drawer. In terms of vehicle and equipment maintenance, battery testing is an essential part of proper maintenance for maximum efficiency. Our use of lithium ion batteries and other new technologies are currently changing the nature of battery use. We will undoubtedly see new kinds of batteries as energy resources change. The battery tester will change as well, but it will always remain an important component of battery use.