TOPDON BT300P Battery Tester: Is It Time for a New Battery?

The TOPDON BT300P Battery Tester will tell you if you need a new battery and let you know if the charging system itself is healthy.

Lexus vehicles are so well made it’s sometimes easy to forget that parts do grow old or simply wear out. In the case of an aging battery, far too many people ignore the warning signs and end up randomly stranded after a short drive or a cold night. (Just ask my brother who drove my mother’s Volvo to work one night and couldn’t get home.) But if you’re a pro or a DIY enthusiast with a battery tester like the TOPDON BT300P, you can prevent that call to AAA (or a sleeping sibling) by routinely checking the health of your charging system and the battery itself.

This is also particularly useful for modern vehicles that are stuffed with wired and wireless technologies that require proper voltage to prevent all sorts of malfunctions.

The BT300P, which can test a battery’s cranking voltage in addition to overall health, is designed to let you know if you need a new battery, can keep running your current battery, or if you need to check your alternator and other charging system components. Since getting this BT300P in for review, I’ve learned a metric ton about the health of my humble fleet’s batteries. And it’s saved me from at least one breakdown.

Here’s everything you need to know about the BT300P and whether or not you should buy one.

Full disclosure: TOPDON is a ClubLexus sponsor and they commissioned this review. All facts have been approved by TOPDON. All opinions remain my own.

Features & Tests

The TOPDON BT300P is a rectangular plastic device with a simple button interface, small screen, and attached positive and negative cables. The kit includes a carrying case with a paper instruction manual and two extra rolls of paper for printing test results. (One roll comes pre-loaded.)

The BT300P offers three testing features —

1. Battery health (health of battery and overall state of charge)
2. Cranking health (tests starting voltage)
3. Charging system health (too high, too low, or just right)

To test the battery health, simply connect the positive and negative cables, select your battery type, and the number of cold cranking amps listed on the battery, then press enter. Please note, however, that, according to TOPDON,

If the battery charge is too high or too low, it will affect the test results. If the battery charge is too high, there is usually floating electricity. In this case, it is generally recommended that customers turn on the car headlights for 2-3 minutes and remove the floating electricity before testing. Low battery may be caused by excessive use of the battery and not charging it in time. In this case, it is also recommended to charge it for a period of time before testing.

In short, don’t test a battery that’s been sitting around too long, nor one that’s been charged too much.

To test the cranking system, navigate to that test in the menu and, following the prompts on screen, start the vehicle. Results will follow with these starting voltages —

• <9.6V is LOW
• 9.6V≤ and <10.7V is NORMAL
• ≧10.7V is GOOD

And, lastly, with the vehicle running, the BT300p can test the health of the charging system at idle and then, once prompted, at 2,500 RPM. Again, results follow on screen.

Printing results is easily done at the press of a button.

Testing the Battery Tester

I used the BT300P to evaluate several vehicles, including a friend’s C6 Corvette, which you see pictured in this post. Here’s a full breakdown —

• 2006 Corvette (3 year old battery, weekly driver)
• LS3 Swapped Roadmaster Wagon (1.5 year old battery, weekly driver)
• 2013 Mustang Boss 302 (6 year old battery, weekly driver)
• 2013 Cadillac ATS (10 year old battery, daily driver)
• 1987 Mercury Cougar (2 year old battery, weekly driver)
• 2013 Toyota Tacoma (1 year old battery, daily driver)

According to TOPDON,

The BT300P adopts the world’s standard conductivity testing technology to test the real-time characteristics of the plates inside the battery to determine the battery’s cold start capability. Comprehensively judge the quality of the battery through parameters such as voltage, CCA, SOC, and SOH.

In retrospect, the results were fairly predictable. Newer batteries on cars more regularly driven were generally healthy. Older batteries on vehicles that sit around too much were nearing the end of their lifespan. My Roadmaster had managed to eat one battery, which was covered under warranty. In the case of my Mustang, the BT300P likely prevented me from getting stranded after too many short drives. And on two occasions, the batteries themselves were too undercharged for proper testing, and the results had to be redone after a quick drive.

In several cases, mostly involving older batteries, I cross-checked the BT300P’s results with the help of my local O’Reilly’s (not sponsored), and the TOPDON product produced similar results without the hassle of having to drive anywhere and/or remove a battery for testing.

TOPDON BT300P Pros & Cons

My overall experience with the TOPDON BT300P is positive, but I did have a few complaints. Here are a list of pros & cons:

Pros

• Simple to set up & quick to use
• Accurate results (verified versus part store testers)
• Routinely testing batteries can help get replacements before a warranty ends

Cons

• The paper likes to jam in the printer if not torn away perfectly each time
• The cranking and charging system tests require two people as the cables are very short
• Undercharged and recently charged batteries can give incorrect results

Who Should Buy a BT300P?

Although the TOPDON BT300P is pitched for professional automotive technicians and DIYers alike, I’m more apt to recommend the product to the pros. Basically, if you need the printer for documentation (to provide to customers who want proof before making an expensive purchase), it’s a great battery tester.

A DIYer with a small or large collection may also find the BT300P useful, especially if they already have trickle-style chargers in place for vehicles that sit a lot.

However, when learning about the BT300P on TOPDON’s website, I stumbled upon the TB6000Pro and would recommend that a little more for DIYers or those with a small collection of cars. Why? The TB6000Pro combines battery testing with battery charging, and it can be live-monitored via Bluetooth. In other words, it’s more useful. Also, outside of the customer experience, I’m not sure a DIYer would want to deal with printing physical paper. That’s not to knock the BT300P, mind you. Just a recommendation for those who might be in a similar situation.

Click HERE to purchase a TOPDON BT300P Battery Tester!

or

Click HERE to purchase a TOPDON TB6000Pro Intelligent Battery Charger & Tester!

Michael S. Palmer

Michael S. Palmer began his career assisting and developing content for Academy Award-winning and studio-based film and television producers. He has been a professional writer since 2008, when he joined the Writers Guild of America West (WGAw). As a journalist and Content Editor/Manager, he has covered numerous emerging imaging, theatrical exhibition, home entertainment, and automotive technologies. He currently spends his days creating original content at the Internet Brands Automotive Group for some of the world's largest online automotive communities, including Ford Truck Enthusiasts, CorvetteForum, ClubLexus, AudiWorld, and LS1Tech. He still owns his first car, a 1987 Mercury Cougar; adores driving his Boss 302 Mustang; and recently teamed with Chevrolet Performance, Holley, Magnaflow, Eaton, Wilwood, Michelin, Chemical Guys, Summit Racing to build his first project car. Installing an LS3 E-ROD Connect & Cruise system into a 1992 Buick Roadmaster Estate Wagon made his eight-passenger wagon faster than a C5 Corvette to 60mph and 50 state emissions legal. His wife and daughter are very patient.