Battery Testers

Battery Testers

Experiencing issues with your electronics? Does your engine take time to turn over when you start it? These sound like battery issues, but they aren't always. Properly testing the battery can help you figure out if the battery truly is the cause, or if something else is creating problems for you.

What's the Difference Between a Battery Tester and a Multimeter?

Your 12 V battery powers all electric and electronic components, starts your car when you've turned on the ignition, and is charged via your alternator. Without it, you can't drive your vehicle. The first step in diagnosing the problem is testing the battery using either a battery tester or a multimeter.

Multimeters, as the name suggestions, take multiple measurements and are therefore several testers in one:

• ohmmeter: measures electrical resistance
• voltmeter: measures voltage
• ammeter: measures amperage

Most will offer other tests, too. Regardless of the tests a multimeter can offer, they're static tests and require knowledge and cross-referencing with charts to interpret the results.

Battery testers, by contrast, include those tests and diagnostics for battery health and performance and starting and charging systems. They also test the battery under load and give clear results.

• good battery
• good battery, needs recharge
• replace, life cycle
• replace, bad cell
• charge, retest

The results immediately tell you next steps. If your battery is in good condition, but you're still experiencing problems with your vehicle, then you can strike the battery off your list of possibilities and continue investigating.

On the other hand, if the battery tester says to replace your battery, you may have just saved yourself hours of needless investigation.

Types of Measurements

Battery testers measure, at a minimum, the following:

• cold cranking amps (CCA)
• state of health (SOH)
• state of charge (SOC)
• voltage
• internal resistance

Depending on the model, you can test starting and charging systems and use them on different battery types.

Key Features to Consider

Before reviewing the range of battery testers available, review the key features you need.

Voltage Range

Some battery testers focus on one voltage, whereas many can test a range. So, what are you testing?

• older motorcycles and some lawn equipment: 6V systems
• most cars, light trucks, and motorcycles: 12V systems
• heavy-duty trucks, commercial vehicles: 24V systems

Choosing the wrong voltage for your needs can lead to inaccurate testing and damage.

Battery Type Compatibility

Ensure your battery tester includes settings for any batteries you plan to test. Purchase a tester with comprehensive capabilities if you plan to test several battery types:

• conventional flooded lead-acid
• AGM flat plate and AGM spiral wound
• gel cell batteries
• start-stop EFB (enhanced flooded battery)
• start-stop AGM

CCA Testing Range

Match your vehicle to the battery tester's CCA testing capabilities.

• Light-duty vehicles: 40-1200 CCA
• Heavy-duty vehicles: up to 2000+ CCA

Types of Battery Testers

Battery testers are not a one-size-fits-all solution. Different types of testers specialize in certain measurements, although you will find some overlap.

Conductance Battery Testers

These testers send an AC voltage through the battery terminals. You usually get results within three seconds, and the test won't stress the battery. Conductance battery testers also don't require a fully charged battery and can be used with the battery still installed in the vehicle.

The test results include CCA, SOH, SOC, and voltage. Conductance battery testers are best for quick diagnostics and regular battery maintenance.

Example from NAPA: NAPA Battery Tester Battery Conductance Tester 12V (NBT PBT100) - https://www.napacanada.com/en/p/NBTPBT100

Conductance Battery & System Testers

If you want to measure conductance and your electrical system, this tester will accomplish the task for you. It tests the following capabilities:

• alternator output and voltage regulation
• starter current draw
• ripple detection for alternator diodes
• voltage
• cranking voltage and time
• charging voltage
• state of charge

They usually export their data via a USB port or a built-in printer. Conductance battery and system tests are best suited for comprehensive electrical diagnostics.

Carbon Pile Load Testers

To simulate real-world starting conditions, you need to apply heavy load to the battery. Carbon pile load testers test alternator output and starting system capacity. Variable load is adjusted for more accurate CCA ratings. They require a fully charged battery for accurate results.

Carbon pile load testers are best for professional shops, highly experienced DIYers, and definitive load testing.

Hydrometer Battery Testers

To test specific gravity of a flooded battery's electrolyte, you need a hydrometer. Hydrometers are best for flooded lead-acid battery maintenance and can only be used on flooded batteries with removable caps.

Additional Features to Look For

Prioritize selecting a battery tester that matches your battery and testing needs. Once you've confirmed those options, consider the following:

• backlit displays for dark engine bays
• built-in thermal printers for service records
• results time and date stamped
• pass/fail indicators with numerical data
• USB data export capability
• battery pack testing for multi-battery systems

When to Test Your Battery

At a minimum, add battery testing to your summer and winter maintenance checks. These two seasons provide the most strain on your battery. Testing your battery at these seasons will give you an indication of whether you should replace your battery before the going gets tough.

However, a few other situations may call for additional testing:

• before long road trips
• when experiencing slow cranking or dim headlights
• when the battery has reached 3+ years of age
• in extreme Canadian temperatures (below 0°C or above 30°C)
• when the battery warning light appears

A battery tester's comprehensive tests can tell you immediately if you need to replace your battery, so you can avoid a dead battery in Canada's rural areas, parks, and other locations where getting help can be difficult.

Focus on Your Needs First

Like many diagnostic tools, a long list of capabilities can excite the mind. If you need a battery tester that can accomplish a list of tasks, ensure you understand what the results mean. Sometimes, simpler really is better.

To find the battery tester most suitable for your needs, view our wide selection of battery testers online. Have more questions? Visit your local NAPA Auto Parts store to speak with an expert about choosing the right battery tester for you.