{"product_id":"kit-li-ion-spot-welder-controller","title":"Li-Ion Spot Welder Controller Kit with Arduino Uno + Relay","description":"\u003ch1\u003eBuild a Precision Li-Ion Battery Spot Welder with Arduino Timing \u0026amp; Safety Interlock\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 Intermediate\u003c\/span\u003e\n  \u003cspan\u003e\u003cstrong\u003eBuild Time:\u003c\/strong\u003e 4-5 hours\u003c\/span\u003e\n  \u003cspan\u003e\u003cstrong\u003eAge:\u003c\/strong\u003e 15-18\u003c\/span\u003e\n  \u003cspan\u003e\u003cstrong\u003eSkill:\u003c\/strong\u003e Precision current-controlled welding with safety interlock design\u003c\/span\u003e\n\u003c\/div\u003e\n\n\u003cp\u003eAssembling a high-current battery pack for an e-bike, solar storage, or a DIY powerwall demands reliable tab connections. This kit turns an Arduino Uno into a capacitor discharge spot welder that delivers controlled, repeatable welds on nickel strips. An ACS712 sensor monitors the actual pulse current in real time, while the safety interlock prevents accidental double-firing — exactly what you need when working with sensitive 18650 cells.\u003c\/p\u003e\n\n\u003ch2\u003eWhat You'll Build\u003c\/h2\u003e\n\u003cp\u003eYou will build a tabletop spot welder controller that uses capacitor banks discharged through a relay to fuse nickel tabs onto Li-Ion cell terminals. The OLED displays weld count, pulse duration, and live current readings from the ACS712. Two tactile buttons let you arm and trigger each weld, with an RTC timestamping every weld session for quality tracking.\u003c\/p\u003e\n\n\u003ch2\u003eWhat You'll Learn\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eDesign a capacitor discharge circuit for high-current welding pulses\u003c\/li\u003e\n  \u003cli\u003eProgram Arduino timing control with relay switching and dead-time prevention\u003c\/li\u003e\n  \u003cli\u003eInterface an ACS712 hall-effect sensor to measure real-time weld current\u003c\/li\u003e\n  \u003cli\u003eImplement a two-button safety interlock sequence to eliminate accidental triggering\u003c\/li\u003e\n  \u003cli\u003eRead and display data on a 0.96-inch OLED, including RTC timestamps\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 20A\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e5V Relay Module\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eDS3231 RTC\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e0.96in OLED\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eTactile Button\u003c\/td\u003e\n\u003ctd\u003e2\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e4700µF 35V Cap\u003c\/td\u003e\n\u003ctd\u003e4\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1N4007 Diode\u003c\/td\u003e\n\u003ctd\u003e5\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\u003ePCB Prototype Board\u003c\/td\u003e\n\u003ctd\u003e2\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e12V 5A PSU\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eSoldering Iron\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eSolder Wire\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\u003eThis kit fits B.Tech ECE\/EEE students building a semester project on precision welding or power electronics, CBSE Class 12 physics enthusiasts exploring capacitor banks, and Smart India Hackathon teams developing battery assembly prototypes. It is equally useful for ATL Tinkering Labs demonstrating controlled high-current switching and for IIT\/NIT\/VIT\/BITS hobbyists assembling their own e-bike or solar battery packs.\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 included in the box to access the AI companion, which can troubleshoot wiring, code, or calibration issues. If you need human help, our team is available on WhatsApp with a typical response time of under an hour.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eIs this welder safe for Li-Ion cells?\u003c\/summary\u003e\u003cp\u003eYes, the two-button safety interlock requires a deliberate arm-then-fire sequence, preventing accidental double pulses. The ACS712 monitors current, and the code enforces a minimum inter-weld cool-down time to avoid overheating cells.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eCan I adjust the weld pulse duration?\u003c\/summary\u003e\u003cp\u003eAbsolutely. The Arduino sketch lets you modify the pulse width in milliseconds, and the OLED shows the real-time current profile so you can fine-tune the weld for different nickel strip thicknesses.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eDoes this kit include the welding electrodes and nickel strips?\u003c\/summary\u003e\u003cp\u003eThe kit includes all electronic controller components and the soldering tools to assemble them. Welding electrodes (copper probes) and nickel strips must be sourced separately, as electrode requirements vary with the battery form factor you plan to weld.\u003c\/p\u003e\u003c\/details\u003e\n\n\u003cdiv class=\"kit-description\"\u003e\n  \u003cp\u003eCapacitor discharge spot welder with Arduino timing control. ACS712 measures pulse current. Safety interlock.\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 20A\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/4-channel-relay-board-for-esp32-30-pin-5v-control\"\u003e5V Relay Module\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/ds3231-real-time-clock-module-i2c-rtc-with-battery-backup\"\u003eDS3231 RTC\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/096in-oled-display-128x64-i2cspi-for-arduino-raspberry-pi\"\u003e0.96in OLED\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\n\u003ca href=\"\/products\/tactile-button-pack-10x-6mm-switches-with-colored-caps-compoden\"\u003eTactile Button\u003c\/a\u003e x2\u003c\/li\u003e\n    \u003cli\u003e4700µF 35V Cap x4\u003c\/li\u003e\n    \u003cli\u003e\n\u003ca href=\"\/products\/diode-variety-pack-1n4007-1n4148-1n5819-zener-assortment\"\u003e1N4007 Diode\u003c\/a\u003e x5\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\n\u003ca href=\"\/products\/esp-wroom-32-breakout-board-pcb-55x52mm\"\u003ePCB Prototype Board\u003c\/a\u003e x2\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/xkc-y26-pnp-5-12v-non-contact-liquid-level-sensor\"\u003e12V 5A PSU\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/soldering-kit-25w-with-solder-wire-flux-paste-compoden\"\u003eSoldering Iron\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/soldering-kit-25w-with-solder-wire-flux-paste-compoden\"\u003eSolder Wire\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 Li-Ion Spot Welder Controller Kit with Arduino Uno + Relay?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The Li-Ion Spot Welder Controller Kit with Arduino Uno + Relay includes all components needed: Arduino Uno R3, ACS712 20A, 5V Relay Module, DS3231 RTC, 0.96in OLED 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 Li-Ion Spot Welder Controller Kit with Arduino Uno + Relay?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"This kit is designed for Intermediate level makers, suitable for ages 15-18. Capacitor discharge spot welder with Arduino timing control. ACS712 measures pulse current. Safety interlock. Estimated build time is 4-5 hrs.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can I buy the Li-Ion Spot Welder Controller Kit with Arduino Uno + Relay online in India?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes, the Li-Ion Spot Welder Controller Kit with Arduino Uno + Relay 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\": \"Li-Ion Spot Welder Controller Kit with Arduino Uno + Relay\",\n  \"description\": \"Capacitor discharge spot welder with Arduino timing control. ACS712 measures pulse current. Safety interlock.\",\n  \"sku\": \"CDN-KIT-1850\",\n  \"brand\": {\"@type\": \"Brand\", \"name\": \"Compoden\"},\n  \"offers\": {\n    \"@type\": \"Offer\",\n    \"url\": \"https:\/\/compoden.in\/products\/kit-li-ion-spot-welder-controller\",\n    \"priceCurrency\": \"INR\",\n    \"price\": \"4370\",\n    \"availability\": \"https:\/\/schema.org\/InStock\",\n    \"seller\": {\"@type\": \"Organization\", \"name\": \"Compoden\"}\n  },\n  \"category\": \"Power \u0026 Energy\"\n}\n\u003c\/script\u003e\u003cp\u003e\u003cstrong\u003eChoose your assembly option:\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSoldering Kit\u003c\/strong\u003e — 25W soldering iron, 60\/40 solder wire, flux, and small perfboard for permanent assembly.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBreadboard Combo\u003c\/strong\u003e — 800-point full-size breadboard with 65-piece jumper wire pack for solderless prototyping.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Compoden","offers":[{"title":"Clone \/ Soldering Kit","offer_id":53469279256941,"sku":"CDN-KIT-1850-CL-SLD","price":3750.0,"currency_code":"INR","in_stock":true},{"title":"Clone \/ Breadboard Combo","offer_id":53469279289709,"sku":"CDN-KIT-1850-CL-BB","price":3260.0,"currency_code":"INR","in_stock":true},{"title":"R3 Original \/ Soldering Kit","offer_id":53469279322477,"sku":"CDN-KIT-1850-R3-SLD","price":6020.0,"currency_code":"INR","in_stock":true},{"title":"R3 Original \/ Breadboard Combo","offer_id":53469279355245,"sku":"CDN-KIT-1850-R3-BB","price":5530.0,"currency_code":"INR","in_stock":true},{"title":"R4 WiFi \/ Soldering Kit","offer_id":53469279388013,"sku":"CDN-KIT-1850-R4-SLD","price":5390.0,"currency_code":"INR","in_stock":true},{"title":"R4 WiFi \/ Breadboard Combo","offer_id":53469279420781,"sku":"CDN-KIT-1850-R4-BB","price":4890.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0999\/3997\/5533\/files\/kit-li-ion-spot-welder-controller.png?v=1781947295","url":"https:\/\/compoden.com\/products\/kit-li-ion-spot-welder-controller","provider":"Compoden","version":"1.0","type":"link"}