ONE DEVICE FITS ALL: Why juggle multiple single-voltage monitors? Engineered for true versatility, it auto-detects and adapts to any standard system: from 6V classic cars and 12V daily drivers to 24V diesel rigs, large RVs, and marine setups. Compatible with all common battery types including Lead-Acid (Flooded, AGM, Gel, EFB) and Lithium-Ion. This is the single, future-proof solution for enthusiasts with diverse vehicles or evolving needs. Note: 6V only for SOC, voltage & temp monitoring; no charging & cranking tests. MONITOR 4 BATTERIES AT ONCE: Go beyond simple voltage readings. This is your proactive battery guardian. It monitors up to 4 batteries simultaneously (ideal for RVs, boats, dual-battery trucks) and sends instant phone alerts for voltage drops, charging failures, or weak cranking—long before a breakdown happens. Sleep well knowing you’re protected. BUILT FOR REAL-WORLD DEMANDS: Leave behind the frustration of dropped signals. Featuring Bluetooth 5.3 for a rock-solid, extended-range connection that works from your home. Housed in a reinforced composite shell, it resists engine-bay heat, vibration, and corrosion where standard plastics fail, with guaranteed long-term IP67 sealing against the elements. FROM DATA TO DECISIONS: Stop guessing. With >99.6% accuracy, you get trustworthy data. Then, use 72-day advanced trend analytics to see your battery’s aging story—perfect for diagnosing intermittent issues, verifying repair results, or planning the most cost-effective replacement before winter or a long trip. SET IT & FORGET IT: Engineered for zero hassle. With reverse polarity protection and short-circuit prevention, installation is safe and simple. Once installed, its near-zero power consumption (1mA) won’t drain your battery, making it a permanent, worry-free sentinel you can trust for years. Notice: For best signal, install away from thick metal obstructions.

Bluetooth Battery Monitor BM300 Pro

Main Features:

1. Compatible with all 6V 12V 24Vvehicle batteries; 

2. Cranking system & Charging system (alternator);

3. Review voltage/Soc/Temperature history in graph mode;

4. Alert mobile phone if some data abnormal;

5. Short-circuit & Reverse connection protection;

6. IP67 Waterproof;

7. List the time of each driving;

8. Data stored in device up to 72 days if out of sync;

9. Ultra-low power consumption, average current: 1 mA;

10. Connect with battery directly, no code;

11.Free app for iOS & Android users;

12.Temp: -30°C~85°C (-22°F~185°F)

Battery Monitor BM300 Pro Principle: Check battery state on phone APP via Bluetooth 5.3 when device is installed;Support Android 6.0 & iOS11 & More