ANCEL BT521: 2024 New copper clamps and chip for ultra-stable contact and 30% more accuracy. Suitable for regular flooded, AGM flat plate/spiral, EFB, and GEL batteries from 100-2000 CCA. EXTEND BATTERY LIFE: Complete 8-step smart charging program (Desulfation, Soft Start, Bulk Charge, Absorption, Analysis, Repair, Float, and Pulse Maintenance) allows for optimization of battery power, without overcharging or battery damage. CAR BATTERY TESTER: Easily test all aspects of your 12V lead-acid battery, health test, cranking test, alternator test, providing SOH (State of Health), SOC (State of Charge), voltage, current, rating, and many other easy-to-understand analytics, and being prepared ensures that your long trips don't end up with a dead battery. BEYOND MAINTENANCE: It's not just a battery trickle charger, it's an advanced battery charger maintainer. Automatic unattended mode, the charger will work with up to 50% power consumption, worry-free smart battery charger for everyday use. SAFE AND RELIABLE: Smart control, temp compensation in hot climates and under-charging in cold climates, reverse, overcurrent, overvoltage, short circuit, overheat protection. Trickle charger with multiple protection ensure the safety charging at anywhere anytime. Feature: 1. 8-segment battery charger, capable of charging various 12V lead-acid batteries. 2. Test the CCA value and health status of 12V lead-acid batteries. 3. Test the vehicle's starting and charging systems. 4. The shortcut key "Fn" can be set to battery batch testing mode or fast charging mode. 5. The maximum current for this charging can be set to 1A/3A/5A. 6. Fully automatic out of office mode, allowing for long-term connectivity. 7. IP65 waterproof, can be used in damp environments. 8. Provide battery repair mode. 9. When the temperature of the charger is too high, the output power will automatically decrease. 10. Built in high and low temperature compensation mechanism, automatically activating winter and summer working modes. 11. Built in overvoltage, overcurrent, overheating, reverse connection, anti overcharging, and anti discharge protection functions.