Battery and Charger Bundle: Includes 4-bay rapid battery charger (ONLY for NiMH batteries), 4-pack of AA 2000mAh rechargeable batteries LED Light Indicator: 1) Battery is charging: LED blinks slow. 2) Battery is fully charged: LED is solid white. 3) The charger detects an error (defective battery or alkaline battery): LED blinks fast. 4) Every time the charger is connected to power all LEDs power up and power off in a quick sequence. Long Battery Life: Pre-charged and ready-to-use rechargeable batteries can be recharged up to 1000 times Low Self-Discharge: Batteries maintain 80% capacity for up to 12 months Fast-Charging: Fully charges 2 AA within 3.5 hours, 4 AA within 7 hours; 2 AAA within 2 hours, 4 AAA within 4 hours Intelligent and Safe Charger: Plug-and-play charger with LED indicators. Charges each battery individually. Latest battery detection technology indicates wrong polarity, prevents overheating and overcharging (turns to trickle charge when battery is full) Travel-friendly Charger: slim, lightweight, with foldable plug In the Box: 1 Charger with Type A (American) Plug (no cable needed). 4 rechargeable AA batteries Ni-MH Battery Tips: Verify device compatibility with 1.2V Ni-MH batteries. Runtime may be shorter than 1.5V alkaline batteries. Check proper fit as Ni-MH batteries are slightly larger than alkaline batteries to comply with IEC standards. Replace all batteries simultaneously and consult the device manual for specific requirements. Charger Tips: Use only Ni-MH specific chargers with independent charging channels and voltage monitoring to prevent overcharging or undercharging. Avoid timer-only chargers and never use chargers designed for other battery types (like NiZn or Li-ion), as this may cause damage or leakage.