FNIRSI BTM-24 Multifunctional car battery tester

The FNIRSI BTM-24 is an advanced yet extremely easy-to-use 12V and 24V battery tester that replaces several diagnostic tools. In a single measurement, you can check the voltage, starting current up to 2000A CCA, state of charge (SOC), state of health (SOH), internal resistance, and the correct operation of the alternator and charging system. It's a quick, clear answer to the question:is the battery working properly, or is it nearing the end of its life?

No more guessing – you know before the battery fails

Dim lights, starting problems, or random electronic errors are the first warning signs. FNIRSI BTM-24 eliminates guesswork – it clearly shows whether the problem is with the battery, alternator, or installation. This allows you to avoid costly "blind" repairs and replacement of functional components.

Non-destructive battery health test – safe and reliable

The device uses a non-destructive diagnostic method, which means that the battery is not loaded during the test. Simply select the battery standard and start the measurement with one click. The result is presented in the form of a clear GOOD / CHARGE / BAD rating along with precise technical parameters – you know exactly what to do next.

Check engine cranking with one click

The One-Tap Cranking Test function records the voltage drop in real time during engine start-up. The tester immediately informs you whether the start-up is within the normal range (>9.6V) or signals a problem. It is an indispensable tool for diagnosing weak batteries and problems with the starting system.

Real-time charging and alternator test while driving

The BTM-24 monitors dynamic, minimum, and maximum charging voltage, showing how the system responds to changes in engine speed and the activation of receivers. A graphical voltage waveform graph allows you to assess the condition of the alternator, voltage regulator, and cables at a glance—no guesswork and no trip to the service station.

Full compatibility with batteries and vehicles

The tester supports 6 battery standards: CCA, EN, DIN, IEC, JIS, and GB, as well as AGM (flat and spiral), GEL, EFB, and classic lead-acid batteries. It works well in passenger cars, motorcycles, ATVs, boats, delivery vehicles, trucks, company fleets, and golf carts – both inside and outside the vehicle.

Clear display and intuitive operation for everyone

The 2.4" color TFT display with day and night modes ensures excellent readability in all conditions. The simple menu guides the user step by step, so the device can be easily used by mechanics, novice drivers, and used car buyers alike.

Maximum safety at work

Robust, insulated crocodile clips with a wide grip range ensure a secure connection to the terminals. Built-in reverse polarity and overvoltage protection protects the battery, vehicle electronics, and the device itself – test without stress or risk.

Well-thought-out design and ready-to-use set

The FNIRSI BTM-24 has an integrated, tear-resistant cable, 61-centimeter clamps, a foldable stand, and a hanging hole. The set includes a tester, instructions, a data cable, and a practical case, so the device is always safe, mobile, and ready to use.

Who is the FNIRSI BTM-24 for?

It is the perfect tool for mechanics, workshops, DIY enthusiasts, new drivers, company fleets, and used car buyers. One tester that gives you confidence, saves you money, and allows you to make decisions based on facts, not assumptions.

Included:

• FNIRSI BTM-24 battery tester
• Test leads with insulated clamps
• User manual
• Data cable
• Carrying case