{"product_id":"cn3791-mppt-solar-battery-charger-module-3-7v-4-2v-12v-jst","title":"CN3791 MPPT Solar Battery Charger Module 3.7V 4.2V 12V JST","description":"\u003ch2\u003eCN3791 MPPT Solar Battery Charger Module – 3.7V\/4.2V, 12V Input, 300KHz PWM\u003c\/h2\u003e\n\u003cp\u003ePower your lithium-ion battery projects more efficiently with the \u003cstrong\u003eCN3791 MPPT Solar Charging Board\u003c\/strong\u003e. Designed for 12V solar panels, this compact module automatically tracks the maximum power point of your solar input, ensuring you extract every last watt of available energy — even as light conditions change throughout the day. Perfect for DIY solar charging stations, remote sensors, battery-powered devices, and portable electronics projects.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMade in Mainland China.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAutomatic MPPT Technology:\u003c\/strong\u003e Continuously tracks and locks onto the solar panel's maximum power point, optimising energy harvest without manual adjustment.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eEasy Plug-and-Play Setup:\u003c\/strong\u003e Connect your 12V solar panel to one side and your lithium polymer (LiPo) battery to the other via the pre-installed 2-pin JST\/PH2.0 connectors — no soldering required.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eComprehensive Charge Management:\u003c\/strong\u003e Supports trickle charging for deeply discharged batteries, automatic recharging, and visual status indicators for charging and charge-complete states.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFlexible Current Settings:\u003c\/strong\u003e Constant current charging is set via an external resistor, allowing you to customise charge current up to 2A for your specific battery capacity.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHigh-Frequency PWM Switching:\u003c\/strong\u003e 300KHz switching frequency minimises ripple and improves efficiency for cleaner, more stable charging.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eParallel Load Support:\u003c\/strong\u003e Powers a connected load in parallel with the battery during charging — ideal for always-on devices.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003ctable style=\"width:100%; border-collapse:collapse;\"\u003e\n  \u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:8px; border:1px solid #ddd;\"\u003e\u003cstrong\u003eInput Voltage\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px; border:1px solid #ddd;\"\u003e12V (Solar Panel)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd style=\"padding:8px; border:1px solid #ddd;\"\u003e\u003cstrong\u003eOutput Voltage\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px; border:1px solid #ddd;\"\u003eNominal 3.7V \/ Full-Stop 4.2V (±1%)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:8px; border:1px solid #ddd;\"\u003e\u003cstrong\u003eMax Charge Current\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px; border:1px solid #ddd;\"\u003eUp to 2A\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd style=\"padding:8px; border:1px solid #ddd;\"\u003e\u003cstrong\u003ePWM Switch Frequency\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px; border:1px solid #ddd;\"\u003e300KHz\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:8px; border:1px solid #ddd;\"\u003e\u003cstrong\u003eBattery Connector\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px; border:1px solid #ddd;\"\u003e2-Pin PH2.0 \/ JST\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd style=\"padding:8px; border:1px solid #ddd;\"\u003e\u003cstrong\u003eCompatible Battery\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px; border:1px solid #ddd;\"\u003eSingle-cell Li-ion \/ LiPo (3.7V)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:8px; border:1px solid #ddd;\"\u003e\u003cstrong\u003eModule Size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px; border:1px solid #ddd;\"\u003e~45 × 20 × 9.5 mm (1.77 × 0.78 × 0.37 in)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd style=\"padding:8px; border:1px solid #ddd;\"\u003e\u003cstrong\u003eWeight\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px; border:1px solid #ddd;\"\u003e7g\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:8px; border:1px solid #ddd;\"\u003e\u003cstrong\u003eOrigin\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px; border:1px solid #ddd;\"\u003eMainland China\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eWhat's in the Box\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e1 × CN3791 MPPT Charging Module\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eImportant Notes\u003c\/h3\u003e\n\u003cp\u003eThis module is designed for use with a \u003cstrong\u003e12V nominal solar panel\u003c\/strong\u003e. Ensure your solar panel's working voltage matches 12V for correct MPPT operation. Color may vary slightly from photos due to monitor calibration. Please allow ±1–2cm measurement deviation due to manual measurement.\u003c\/p\u003e\n\n\u003ch3\u003eRelated Products You May Like\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003ca href=\"\/products\/22awg-glass-tube-fuse-holder-5x20mm-6x30mm-screw-type-10-pack\"\u003e10-Pack 22AWG Glass Tube Fuse Holder 5x20mm \u0026amp; 6x30mm Screw\u003c\/a\u003e – Protect your circuits with reliable inline fuse holders.\u003c\/li\u003e\n  \u003cli\u003e\n\u003ca href=\"\/products\/140w-usb-c-fast-charging-adapter-auto-power-off-overcharge-protection\"\u003e140W USB-C Fast Charger with Auto Power-Off Overcharge Protection\u003c\/a\u003e – High-power USB-C charging with intelligent battery protection.\u003c\/li\u003e\n  \u003cli\u003e\n\u003ca href=\"\/products\/100w-dual-port-car-charger-starlink-mini-fast-charging\"\u003e100W Dual-Port Car Charger for Starlink Mini – Fast Charging\u003c\/a\u003e – Versatile high-output charging for on-the-go power needs.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eFor more information on solar energy standards and safe electrical practices, visit the \u003ca href=\"https:\/\/www.energy.gov\/eere\/solar\/solar-energy-technologies-office\" target=\"_blank\" rel=\"nofollow noopener\"\u003eU.S. Department of Energy – Solar Energy Technologies Office\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003ch4\u003eQ: What type of battery is compatible with the CN3791 MPPT charging module?\u003c\/h4\u003e\n\u003cp\u003eA: The CN3791 charging module is designed for single-cell lithium-ion or lithium polymer (LiPo) batteries with a nominal voltage of 3.7V and a full-charge voltage of 4.2V. It is not suitable for multi-cell packs or other battery chemistries such as NiMH or lead-acid without modification.\u003c\/p\u003e\n\u003ch4\u003eQ: What solar panel do I need to use with this module?\u003c\/h4\u003e\n\u003cp\u003eA: This CN3791 MPPT module requires a solar panel with a working (nominal) voltage of 12V. Using a panel with a different voltage may result in improper operation or damage to the module or battery.\u003c\/p\u003e\n\u003ch4\u003eQ: How do I set the charging current for my battery?\u003c\/h4\u003e\n\u003cp\u003eA: The constant current charging level is configured via an external resistor on the board. By selecting the appropriate resistor value, you can set the charge current up to a maximum of 2A. Consult the CN3791 datasheet for the specific resistor-to-current formula.\u003c\/p\u003e\n\u003ch4\u003eQ: Does the module support charging while simultaneously powering a load?\u003c\/h4\u003e\n\u003cp\u003eA: Yes. The CN3791 module supports a load connected in parallel with the battery. This means your connected device can continue to operate while the battery is being charged from the solar panel.\u003c\/p\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\": \"https:\/\/schema.org\", \"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What type of battery is compatible with the CN3791 MPPT charging module?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"The CN3791 charging module is designed for single-cell lithium-ion or lithium polymer (LiPo) batteries with a nominal voltage of 3.7V and a full-charge voltage of 4.2V. It is not suitable for multi-cell packs or other battery chemistries such as NiMH or lead-acid without modification.\"}}, {\"@type\": \"Question\", \"name\": \"What solar panel do I need to use with this module?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"This CN3791 MPPT module requires a solar panel with a working (nominal) voltage of 12V. Using a panel with a different voltage may result in improper operation or damage to the module or battery.\"}}, {\"@type\": \"Question\", \"name\": \"How do I set the charging current for my battery?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"The constant current charging level is configured via an external resistor on the board. By selecting the appropriate resistor value, you can set the charge current up to a maximum of 2A. Consult the CN3791 datasheet for the specific resistor-to-current formula.\"}}, {\"@type\": \"Question\", \"name\": \"Does the module support charging while simultaneously powering a load?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes. The CN3791 module supports a load connected in parallel with the battery. This means your connected device can continue to operate while the battery is being charged from the solar panel.\"}}]}\u003c\/script\u003e","brand":"Oasis Select","offers":[{"title":"United States","offer_id":47710864572521,"sku":"200007763:201336106","price":25.12,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0679\/7931\/3257\/files\/S0064ddcc840a445492e866d7127fb949j.webp?v=1782061206","url":"https:\/\/oasis-select.com\/products\/cn3791-mppt-solar-battery-charger-module-3-7v-4-2v-12v-jst","provider":"Oasis Select","version":"1.0","type":"link"}