FOXWELL BC521 4-in-1 Battery Charger & Tester – 5A 12V Smart Battery Maintainer & Trickle Charge, Starting/Charging System Tester, 8-Stage Charging, Battery Repair, Long Term Use for Car/RV/Motorcycle

Smart 8-Stage Charging for Longer Battery Life — Standard battery chargers blindly push power and risk overheating. This smart car battery charger uses an advanced 8-stage charging process — including Desulfation, Soft Start, Float, and Pulse Repair — to adapt automatically to your battery’s condition instead of forcing power into it. Choose from 5A / 3A / 1A modes to match different battery sizes, while built-in temperature control lets you safely leave it connected overnight or during storage without fear of overcharging.Accurate Battery Testing Before Charging — Don’t guess battery condition anymore! More than a charger, BC521 can be a true car battery tester to check your 12V battery’s real condition with 99.9% accuracy, including voltage, SOH, SOC, internal resistance, cranking performance, and alternator status. The clear LCD display shows whether your battery needs charging, repair, or replacement — helping you avoid wasted time and unexpected breakdowns.Bring Sleeping Batteries Back to Life — Don’t replace your battery too soon. This smart battery maintainer uses Maintainer Mode to save batteries you thought were dead, recovering deeply discharged and sulfated batteries that have sat unused for weeks or months — restoring lost capacity and extending battery life. Once fully charged, this trickle charger automatically switches to Unattended Mode, maintaining optimal voltage to keep your battery fully charged at all times without the need to unplug — perfect for seasonal vehicles and long-term storage.Built‑In Safety & Outdoor Durability — This 汽车用品 battery charger protects both you and your battery from risks during unattended charging, such as sparks, overcharging, and overheating, with 6 built‑in safety features: over‑voltage, over‑current, overheating, reverse polarity, overcharge, and over-discharge. Additionally, its IP65 waterproofing and flame‑retardant housing ensure safe use both indoors and outdoors, while temperature compensation keeps your battery healthy in extreme conditions.Easy for Anyone to Use — Designed for everyday drivers, not just professionals. The clear LCD and LED indicators show charging status and battery health at a glance without guessing. One-touch FN hotkey recalls your last charging mode (Quick Charging) or runs a Battery Test instantly, saving time on repeated tasks. Review past charging and test history to track battery performance over time. Plus, it's clear instructions will make setup fast and frustration-free.