{"product_id":"adafruit-390-usb-dc-solar-lithium-ion-polymer-charger-rev-c","title":"Adafruit 390 USB \/ DC \/ Solar Lithium Ion\/Polymer charger - Rev C","description":"\u003cmeta name=\"description\" content=\"Buy Adafruit 390 USB \/ DC \/ Solar Lithium Ion\/Polymer charger - Rev C online in India at best price from The Engineer Store, Bengaluru. Authentic product, 7-day warranty on manufacturing defects, fast delivery across India.\"\u003e\n\n\u003ch1\u003eAdafruit 390 USB \/ DC \/ Solar Lithium Ion\/Polymer charger - Rev C\u003c\/h1\u003e\n\n\u003cp\u003eThe Adafruit 390 is a versatile multi-input lithium ion and polymer battery charger that accepts power from USB, DC barrel connectors, and solar panels simultaneously, intelligently prioritizing input sources to optimize charging efficiency. Electronics engineers, IoT developers, and renewable energy project builders rely on this charger to safely manage battery charging in portable devices, wearables, and off-grid solar applications. This product solves the critical challenge of safely charging lithium-based batteries from multiple power sources without overcharging, thermal runaway, or battery degradation.\u003c\/p\u003e\n\n\u003ch2\u003eProduct Overview\u003c\/h2\u003e\n\n\u003cp\u003eThe Adafruit 390 Rev C employs an intelligent power management system that automatically selects the optimal charging source when multiple inputs are connected. The charger features a dedicated lithium ion polymer protection circuit that monitors battery voltage, charging current, and temperature in real-time, ensuring safe operation within manufacturer specifications. The device supports constant-current constant-voltage (CC-CV) charging topology, delivering up to 500mA charging current with automatic termination when the battery reaches full capacity. The solar input circuit includes maximum power point tracking (MPPT) simulation through dynamic voltage regulation, allowing efficient energy harvesting from small solar panels even under varying light conditions.\u003c\/p\u003e\n\n\u003cp\u003eThe Rev C iteration includes improved thermal management with a larger heat-dissipation footprint and refined input protection circuitry that handles voltage transients from unstable solar sources. The charger integrates a JST-PH 2.0mm connector for battery connection, providing secure mechanical coupling while maintaining low contact resistance. Built-in status indicators provide real-time feedback through LED indicators showing charging status, input source selection, and fault conditions. The compact form factor measures approximately 1.5 inches by 1.2 inches, making it ideal for embedded applications where space is constrained.\u003c\/p\u003e\n\n\u003ch2\u003eKey Specifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpecification\u003c\/td\u003e\n\u003ctd\u003eDetails\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Type\u003c\/td\u003e\n\u003ctd\u003eMulti-Input Lithium Ion\/Polymer Battery Charger\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eAdafruit Industries\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOrigin\u003c\/td\u003e\n\u003ctd\u003eOriginal\/Authentic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e7 days on manufacturing defects\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShipping\u003c\/td\u003e\n\u003ctd\u003e1-5 days from Bengaluru\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDelivery\u003c\/td\u003e\n\u003ctd\u003e7-8 days across India\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSupport\u003c\/td\u003e\n\u003ctd\u003e24\/7 via Email and WhatsApp\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput Voltage USB\u003c\/td\u003e\n\u003ctd\u003e5V DC via micro USB connector\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput Voltage DC\u003c\/td\u003e\n\u003ctd\u003e6V to 12V DC via barrel connector\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput Voltage Solar\u003c\/td\u003e\n\u003ctd\u003e6V to 12V DC from solar panel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Charging Current\u003c\/td\u003e\n\u003ctd\u003e500mA at 5V input\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery Connector\u003c\/td\u003e\n\u003ctd\u003eJST-PH 2.0mm polarized connector\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProtection Features\u003c\/td\u003e\n\u003ctd\u003eOvercharge, overcurrent, thermal shutdown, reverse polarity\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eTriple Input Capability: Simultaneously accepts USB, DC barrel, and solar panel inputs with automatic source prioritization for maximum flexibility in diverse power scenarios\u003c\/li\u003e\n\u003cli\u003eIntelligent Power Management: Dynamically selects the optimal input source based on voltage and current availability, preventing conflicts and optimizing charging efficiency\u003c\/li\u003e\n\u003cli\u003e500mA Constant Current Output: Delivers reliable 500mA charging current suitable for single-cell lithium ion and polymer batteries up to 2000mAh capacity\u003c\/li\u003e\n\u003cli\u003eComprehensive Safety Protection: Integrated overcharge protection at 4.2V per cell, overcurrent limiting, thermal shutdown at 60 degrees Celsius, and reverse polarity protection\u003c\/li\u003e\n\u003cli\u003eSolar MPPT Simulation: Dynamic voltage regulation tracks optimal operating point of small solar panels, improving energy harvesting efficiency in low-light conditions\u003c\/li\u003e\n\u003cli\u003eReal-Time Status Indicators: Dual LED indicators provide instant visual feedback on charging status and input source selection\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eApplications and Use Cases\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003ePortable IoT Devices: Powers continuous operation of remote sensor nodes, GPS trackers, and environmental monitoring systems that require reliable battery charging from multiple intermittent sources\u003c\/li\u003e\n\u003cli\u003eSolar-Powered Wearables: Charges smartwatches, fitness trackers, and health monitoring devices equipped with small solar panels for extended outdoor operation without USB dependency\u003c\/li\u003e\n\u003cli\u003eOff-Grid Emergency Systems: Maintains charged backup batteries in emergency communication devices, portable lighting systems, and survival kits using solar and DC power sources\u003c\/li\u003e\n\u003cli\u003eRobotics and Drone Projects: Provides safe charging for lithium polymer batteries in autonomous robots, quadcopters, and unmanned vehicles with multiple power input options during field operations\u003c\/li\u003e\n\u003cli\u003eEducational Electronics Projects: Enables students and hobbyists to build renewable energy-powered prototypes with proper battery management and protection mechanisms\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eHow to Use\u003c\/h2\u003e\n\n\u003cp\u003eBegin by identifying your battery type and confirming it is a single-cell lithium ion or lithium polymer battery rated between 3.0V and 4.2V nominal voltage. Connect your battery to the JST-PH 2.0mm connector, ensuring correct polarity with the red wire to positive and black wire to negative terminals. Select your preferred input source: connect a 5V micro USB power adapter for standard charging, attach a 6V to 12V DC power supply via the barrel connector for faster charging, or connect a compatible 6V to 12V solar panel for renewable energy charging. The charger will automatically prioritize inputs if multiple sources are connected simultaneously, with solar input having secondary priority after USB and DC inputs.\u003c\/p\u003e\n\n\u003cp\u003eMonitor the LED indicators during operation: a red LED indicates active charging, while a green LED indicates the battery has reached full charge and charging has terminated. The charger automatically enters trickle charge mode to maintain battery voltage at 4.2V without overcharging. For optimal performance with solar panels, position the panel in direct sunlight and ensure the voltage output remains between 6V and 12V under your specific lighting conditions. If the charger becomes warm to the touch during operation, reduce ambient temperature or ensure adequate airflow around the device. Always disconnect the battery when not in use for extended periods to preserve battery health and prevent self-discharge.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\n\u003cdetails\u003e\n\u003csummary\u003eCan I charge multiple batteries simultaneously with the Adafruit 390?\u003c\/summary\u003e\n\u003cp\u003eNo, the Adafruit 390 is designed for single-battery charging only. The JST-PH connector supports one battery at a time. Attempting to connect multiple batteries in parallel is not recommended as it bypasses individual battery protection and creates unbalanced charging conditions. For multi-battery applications, use multiple chargers or a dedicated multi-cell battery management system.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails\u003e\n\u003csummary\u003eWhat is the difference between USB and DC barrel input charging speeds?\u003c\/summary\u003e\n\u003cp\u003eUSB input provides 5V at up to 500mA charging current, delivering approximately 2.5W of power. DC barrel input accepts 6V to 12V, allowing higher charging currents when the input voltage is sufficient. A 12V input at 500mA delivers 6W of power, enabling faster charging of larger capacity batteries. The charger intelligently limits current based on input voltage to maintain safe operating conditions and prevent thermal stress.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails\u003e\n\u003csummary\u003eHow does the solar input perform in cloudy or low-light conditions?\u003c\/summary\u003e\n\u003cp\u003eSolar charging performance degrades significantly in low-light conditions due to reduced photovoltaic output. The MPPT simulation circuit in the Adafruit 390 continuously adjusts the load impedance to extract maximum available power from the solar panel. In direct sunlight, a 6V 1W solar panel delivers approximately 200mA charging current. In cloudy conditions, output drops to 20-50mA, providing trickle charging only. For reliable operation, position the solar panel in direct sunlight and consider supplementing with USB or DC power sources during extended cloudy periods.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails\u003e\n\u003csummary\u003eWhen will I receive my order?\u003c\/summary\u003e\n\u003cp\u003eOrders are dispatched within 1-5 business days from our Bengaluru warehouse. Delivery takes 7-8 days to most locations across India.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails\u003e\n\u003csummary\u003eWhat is your return and warranty policy?\u003c\/summary\u003e\n\u003cp\u003eWe offer a 7-day return policy on manufacturing defects only. Contact support within 7 days of receipt for free replacement or full refund. Not applicable for user damage or misuse.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails\u003e\n\u003csummary\u003eAre bulk discounts available?\u003c\/summary\u003e\n\u003cp\u003eYes, wholesale pricing for orders of 10 or more units. Contact our sales team via WhatsApp or email for a customized bulk quote.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003ch2\u003eWhy Buy from The Engineer Store\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eGenuine Products: Sourced directly from authorized distributors with authentication\u003c\/li\u003e\n\u003cli\u003eExpert Team: Our technical team validates every product before listing\u003c\/li\u003e\n\u003cli\u003eFast Shipping: Dispatched within 1-5 days from our Bengaluru warehouse\u003c\/li\u003e\n\u003cli\u003ePan-India Delivery: 7-8 days to Mumbai, Delhi, Chennai, Hyderabad, Pune, Kolkata\u003c\/li\u003e\n\u003cli\u003ePayment Options: COD, UPI, credit\/debit cards, net banking, EMI available\u003c\/li\u003e\n\u003cli\u003eTechnical Support: 24\/7 expert guidance via email and WhatsApp\u003c\/li\u003e\n\u003cli\u003eReturns: 7-day return policy on manufacturing defects only\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eBuy Adafruit 390 USB \/ DC \/ Solar Lithium Ion\/Polymer charger - Rev C Online in India\u003c\/h2\u003e\n\u003cp\u003ePurchase the \u003cstrong\u003eAdafruit 390 USB \/ DC \/ Solar Lithium Ion\/Polymer charger - Rev C\u003c\/strong\u003e online at \u003ca href=\"https:\/\/theengineerstore.in\"\u003eThe Engineer Store\u003c\/a\u003e, India's trusted source for genuine electronics. We deliver across Bengaluru, Mumbai, Delhi, Chennai, Hyderabad, Pune, Kolkata, Ahmedabad, Jaipur, and Surat. Get the best price on \u003cstrong\u003eAdafruit 390 USB \/ DC \/ Solar Lithium Ion\/Polymer charger - Rev C\u003c\/strong\u003e with fast shipping and expert support.\u003c\/p\u003e\n\u003cp\u003eOur team in Bengaluru is available 24\/7 to support your journey from product selection to project completion.\u003c\/p\u003e","brand":"My Store","offers":[{"title":"Default Title","offer_id":43853766426787,"sku":"TES-EV02683","price":2002.34,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0628\/4479\/7091\/products\/390-06-228x228.jpg?v=1704192001","url":"https:\/\/www.theengineerstore.in\/hi\/products\/adafruit-390-usb-dc-solar-lithium-ion-polymer-charger-rev-c","provider":"The Engineer Store","version":"1.0","type":"link"}