{"product_id":"kit-18650-cell-capacity-tester","title":"18650 Cell Capacity Tester Kit with Arduino Uno","description":"\u003ch1\u003e18650 Cell Capacity Tester Kit with Arduino Uno – Measure True mAh of Any 18650 Cell\u003c\/h1\u003e\n\n\u003cp class=\"value-summary\"\u003eEvery part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.\u003c\/p\u003e\n\n\u003cdiv class=\"specs-strip\"\u003e\n  \u003cspan\u003e\u003cstrong\u003eDifficulty:\u003c\/strong\u003e Beginner\u003c\/span\u003e\n  \u003cspan\u003e\u003cstrong\u003eBuild Time:\u003c\/strong\u003e 3-4 hrs\u003c\/span\u003e\n  \u003cspan\u003e\u003cstrong\u003eAge:\u003c\/strong\u003e 5-15\u003c\/span\u003e\n  \u003cspan\u003e\u003cstrong\u003eSkill:\u003c\/strong\u003e Constant current circuits \u0026amp; current sensing\u003c\/span\u003e\n\u003c\/div\u003e\n\n\u003cp\u003eUncover the real capacity of your 18650 lithium-ion cells—not the label rating. This kit gives you a dedicated constant-current discharge tester with an LCD readout, so you can bin cells, match capacities, and build safe, reliable battery packs. Perfect for makers, students, and anyone who salvages cells from old laptops or power banks.\u003c\/p\u003e\n\n\u003ch2\u003eWhat You'll Build\u003c\/h2\u003e\n\u003cp\u003eA standalone 18650 cell capacity meter that displays voltage, current, and accumulated mAh on a crisp 16x2 LCD. The circuit uses a MOSFET as a voltage-controlled load and an ACS712 Hall-effect sensor to precisely track current, eliminating guesswork. You’ll have a benchtop tool you can reuse for every battery project.\u003c\/p\u003e\n\n\u003ch2\u003eWhat You'll Learn\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eConstant-current discharge using an N-channel MOSFET\u003c\/li\u003e\n  \u003cli\u003eCurrent sensing with ACS712 5A module and noise filtering\u003c\/li\u003e\n  \u003cli\u003eVoltage measurement with Arduino analog dividers\u003c\/li\u003e\n  \u003cli\u003eCalculating capacity (mAh) by integrating discharge current over time\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eKit Contents\u003c\/h2\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eComponent\u003c\/th\u003e\n\u003cth\u003eQuantity\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eArduino Uno R3\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eACS712 5A\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eIRF540N MOSFET\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e16x2 LCD\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eI2C Backpack\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e10Ω 5W Resistor\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e100Ω Gate Resistors\u003c\/td\u003e\n\u003ctd\u003e3\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e10kΩ Resistors\u003c\/td\u003e\n\u003ctd\u003e5\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e400-pt Breadboard\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM-M Wires\u003c\/td\u003e\n\u003ctd\u003e20\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e9V Battery Snap\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhy Buy This Kit Instead of Sourcing Parts Separately\u003c\/h2\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eFactor\u003c\/th\u003e\n\u003cth\u003eSourcing Separately\u003c\/th\u003e\n\u003cth\u003eCompoden Kit\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eCompatibility checks\u003c\/td\u003e\n\u003ctd\u003eYou verify every part\u003c\/td\u003e\n\u003ctd\u003ePre-tested as a system\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eBuild support\u003c\/td\u003e\n\u003ctd\u003eForums and scattered tutorials\u003c\/td\u003e\n\u003ctd\u003eAI companion trained on this exact project\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eTime to first working build\u003c\/td\u003e\n\u003ctd\u003eDays of debugging\u003c\/td\u003e\n\u003ctd\u003eHours, with step-by-step guidance\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eShipping coordination\u003c\/td\u003e\n\u003ctd\u003eMultiple sellers, multiple delays\u003c\/td\u003e\n\u003ctd\u003eOne shipment from Bengaluru in 3-5 days\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWho This Kit Is For\u003c\/h2\u003e\n\u003cp\u003eCBSE Class 11‑12 physics students exploring practical electronics, B.Tech ECE\/EEE freshmen undertaking mini‑projects, ATL Tinkering Lab facilitators running energy measurement workshops, and hobbyists salvaging 18650 cells from old laptop batteries. If you’ve ever wondered whether your cells deliver the promised 2500 mAh, this kit is for you.\u003c\/p\u003e\n\n\u003ch2\u003eBuilt and Backed by Compoden\u003c\/h2\u003e\n\u003cp\u003eEvery Compoden kit ships with an AI build companion trained on this exact project — accessible via a QR code on the box, with WhatsApp and email backup. We've spent 10 years building projects for makers, schools, and institutions across India. If a part fails because of a manufacturing defect, replace it free within 7 days.\u003c\/p\u003e\n\n\u003cdetails\u003e\u003csummary\u003eWhat if I get stuck during the build?\u003c\/summary\u003e\u003cp\u003eScan the QR code on your kit box to access the AI companion, trained on this exact setup. You can also message us on WhatsApp for human assistance within 24 hours.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eCan I test cells other than 18650s?\u003c\/summary\u003e\u003cp\u003eThe kit is designed for single 18650 lithium-ion cells (3.7V nominal). With external battery holders and appropriate resistor changes, you can test other cylindrical Li-ion sizes like 14500 or 21700; our AI companion can guide you through the adjustments.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eHow accurate is the mAh reading?\u003c\/summary\u003e\u003cp\u003eWith proper calibration using the included guide, accuracy is typically within 5%. The ACS712 offset calibration and a stable reference voltage are critical; the AI companion walks you through both steps.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eDo I need a separate power supply for the Arduino?\u003c\/summary\u003e\u003cp\u003eYes. The Arduino can be powered via USB or the included 9V battery snap. The 18650 cell under test powers only the constant-current load circuit, keeping the measurements dedicated and isolated.\u003c\/p\u003e\u003c\/details\u003e\n\n\u003cdiv class=\"kit-description\"\u003e\n  \u003cp\u003eConstant current discharge via transistor. ACS712 and voltage divider calculate mAh capacity of 18650 cell.\u003c\/p\u003e\n  \u003ch4\u003eWhat's in this kit\u003c\/h4\u003e\n  \u003cul\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/uno-r3-ch340g-atmega328p-board-arduino-compatible\"\u003eArduino Uno R3\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/acs712-5a-current-sensor-module-precise-hall-effect-measurement\"\u003eACS712 5A\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/irf540n-mosfet-100v-33a-n-channel-power-transistor-compoden\"\u003eIRF540N MOSFET\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/16x2-lcd-display-module-16x2-character-blue-backlight\"\u003e16x2 LCD\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/i2c-backpack-pcf8574-i2c-adapter-for-lcd-displays\"\u003eI2C Backpack\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e10Ω 5W Resistor\u003c\/li\u003e\n    \u003cli\u003e100Ω Gate Resistors x3\u003c\/li\u003e\n    \u003cli\u003e\n\u003ca href=\"\/products\/resistor-variety-pack-100-pcs-10-values-14w-carbon-film\"\u003e10kΩ Resistors\u003c\/a\u003e x5\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/breadboard-standard-bundle-830400-tie-points-for-prototyping\"\u003e400-pt Breadboard\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003eM-M Wires x20\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/9v-battery-snap-connector-with-15cm-wires-compoden\"\u003e9V Battery Snap\u003c\/a\u003e\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is included in the 18650 Cell Capacity Tester Kit with Arduino Uno?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The 18650 Cell Capacity Tester Kit with Arduino Uno includes all components needed: Arduino Uno R3, ACS712 5A, IRF540N MOSFET, 16, I2C Backpack and more. Everything is pre-tested for compatibility and shipped from Bengaluru, India.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What skill level is required for the 18650 Cell Capacity Tester Kit with Arduino Uno?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"This kit is designed for Beginner level makers, suitable for ages 5-15. Constant current discharge via transistor. ACS712 and voltage divider calculate mAh capacity of 18650 cell. Estimated build time is 3-4 hrs.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can I buy the 18650 Cell Capacity Tester Kit with Arduino Uno online in India?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes, the 18650 Cell Capacity Tester Kit with Arduino Uno is available online at Compoden (compoden.in), India's AI-powered electronics and robotics store. Ships from Bengaluru in 1-5 business days across India.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"Product\",\n  \"name\": \"18650 Cell Capacity Tester Kit with Arduino Uno\",\n  \"description\": \"Constant current discharge via transistor. ACS712 and voltage divider calculate mAh capacity of 18650 cell.\",\n  \"sku\": \"CDN-KIT-1809\",\n  \"brand\": {\"@type\": \"Brand\", \"name\": \"Compoden\"},\n  \"offers\": {\n    \"@type\": \"Offer\",\n    \"url\": \"https:\/\/compoden.in\/products\/kit-18650-cell-capacity-tester\",\n    \"priceCurrency\": \"INR\",\n    \"price\": \"1325\",\n    \"availability\": \"https:\/\/schema.org\/InStock\",\n    \"seller\": {\"@type\": \"Organization\", \"name\": \"Compoden\"}\n  },\n  \"category\": \"Power \u0026 Energy\"\n}\n\u003c\/script\u003e","brand":"Compoden","offers":[{"title":"Clone","offer_id":53469272670573,"sku":"CDN-KIT-1809-CL","price":1490.0,"currency_code":"INR","in_stock":true},{"title":"R3 Original","offer_id":53469272703341,"sku":"CDN-KIT-1809-R3","price":3760.0,"currency_code":"INR","in_stock":true},{"title":"R4 WiFi","offer_id":53469272736109,"sku":"CDN-KIT-1809-R4","price":3130.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0999\/3997\/5533\/files\/kit-18650-cell-capacity-tester.png?v=1781947231","url":"https:\/\/compoden.com\/products\/kit-18650-cell-capacity-tester","provider":"Compoden","version":"1.0","type":"link"}