--- product_id: 568742880 title: "4 pcs 3S 40A PCB Protection Board 18650 Lithium Battery Protection Board Li-ion Lithium Battery Charger PCB BMS 11.1V 12V 12.6V with Balance Charging with Nickel strip" brand: "youmile" price: "€ 20.26" currency: EUR in_stock: true reviews_count: 8 url: https://www.desertcart.pt/products/568742880-4-pcs-3s-40a-pcb-protection-board-18650-lithium-battery store_origin: PT region: Portugal --- # 40A max continuous discharge current Supports 3S lithium-ion battery packs (11.1V nominal) Multi-layer protection: overcharge, overdischarge, short circuit 4 pcs 3S 40A PCB Protection Board 18650 Lithium Battery Protection Board Li-ion Lithium Battery Charger PCB BMS 11.1V 12V 12.6V with Balance Charging with Nickel strip **Brand:** youmile **Price:** € 20.26 **Availability:** ✅ In Stock ## Summary > 🛠️ Power your projects with precision and protection — don’t get left behind! ## Quick Answers - **What is this?** 4 pcs 3S 40A PCB Protection Board 18650 Lithium Battery Protection Board Li-ion Lithium Battery Charger PCB BMS 11.1V 12V 12.6V with Balance Charging with Nickel strip by youmile - **How much does it cost?** € 20.26 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.pt](https://www.desertcart.pt/products/568742880-4-pcs-3s-40a-pcb-protection-board-18650-lithium-battery) ## Best For - youmile enthusiasts ## Why This Product - Trusted youmile brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Ready-to-Install Kit:** Includes 4 protection boards plus a 1m nickel strip for quick, professional-grade assembly and balance charging. - • **Powerhouse 40A Discharge:** Push your battery packs to the limit with a robust 40A continuous current rating, perfect for high-demand devices. - • **Precision Voltage Control:** Maintain optimal battery health with balanced charging from 12.6V to 13.6V, ensuring longevity and safety. - • **Comprehensive Safety Suite:** Stay worry-free with integrated overcharge, overdischarge, overcurrent, and short circuit protections. - • **Universal Lithium Compatibility:** Seamlessly supports 18650, 26650, and lithium polymer batteries, making it your go-to BMS for versatile projects. ## Overview This 4-pack of 3S 40A PCB protection boards offers advanced battery management for lithium-ion packs, delivering up to 40A continuous discharge and 20A charge current. Featuring multi-layer safety protections and balanced charging capabilities, it supports various lithium battery types including 18650 and 26650 cells. Ideal for professionals and enthusiasts seeking reliable, high-performance battery protection with easy installation. ## Description Specifications: Charging voltage:12.6V ~ 13.6V Continuous discharge current (upper limit): 40A (if the cooling environment is not good, please reduce the load current ) Continuous charge current (upper limit): 20A Size:41 mm×55 mm×3.4mm/1.61 ×2.16×0.13in Scope of application:Suitable for lithium batteries with a nominal voltage of 3.7V and a full voltage of 4.2V (including 18650, 26650, and polymer lithium batteries, there is no limitation on size) Note： 1.To successful starting the drill requires three 15C-20C power batteries, or six 10C-15C power batteries (ordinary 18650 battery can not start the drill). 2.Strictly according to the diagram wiring，0V/4.2V/8.4V/12.6V,Do not touch any components on the board when soldering the wire. 3.When welding the battery for the first time or charging, as long as a single battery exceeds 4.2V, the '430' resistor will heat up and discharge (discharge to about 4.19V and stop heating). If the '430' resistor is seriously hot (it is too hot to touch), please check whether the wrong wire is connected. 4.Do not mix the good battery and poor battery to use.The internal resistance of 3 battery capacity are closer will be better. Package includes： 4 x 3S 40A PCB Protection Board(Balanced version) 1 x Nickel Strip(1m) ## Features - 【What it does】: The 3S 40A protection board can effectively prevent various problems encountered when charging the battery and avoid accidents. - 【Multiple protection】: The protection board has precise overcharge protection, over discharge protection, overcurrent protection, short circuit protection and other protection functions. - 【Current and voltage】: Charging voltage: DC 12.6V~13.6V;Continuous discharge current: maximum 40A (if the heat dissipation environment is not good, please reduce the load current);Continuous charging current: maximum 20A. - 【Note】: Do not mix good batteries and bad batteries together, and new and old batteries can't be used together.Strictly according to the diagram wiring，0V/4.2V/8.4V/12.6V. - 【Scope of application】: The protection board is suitable for lithium-ion batteries, and can also be used for ternary batteries, manganese acid batteries, and cobalt acid batteries. ## Technical Specifications | Specification | Value | |---------------|-------| | Amperage | 40 Amps | | Asin | B0CD753437 | | Best Sellers Rank | 17,008 in Electronics & Photo (See Top 100 in Electronics & Photo) 155 in Household Battery Chargers | | Brand Name | Youmile | | Colour | green | | Compatible Devices | Lithium-ion batteries (e.g. 18650, 26650 and lithium polymer batteries) | | Connector Types | Nickel strip | | Country Of Origin | China | | Current Rating | 20 Amps | | Customer Reviews | 4.3 4.3 out of 5 stars (93) 4.3 out of 5 stars | | Input Voltage | 13.6 Volts (DC) | | Item Dimensions D X W X H | 0.3D x 5.5W x 0.3H centimetres | | Manufacturer | Youmile | | Manufacturer Part Number | JK-YM-689 | | Model Number | JK-YM-689 | | Number Of Items | 4 | | Number Of Packs | 4 | | Output Voltage | 13.6 Volts (DC) | | Specification Met | CE | | Unit Count | 4.0 count | ## Product Details - **Brand:** Youmile - **Colour:** green - **Output voltage:** 13.6 Volts (DC) - **Specification met:** CE - **Input voltage:** 13.6 Volts (DC) ## Images ![4 pcs 3S 40A PCB Protection Board 18650 Lithium Battery Protection Board Li-ion Lithium Battery Charger PCB BMS 11.1V 12V 12.6V with Balance Charging with Nickel strip - Image 1](https://m.media-amazon.com/images/I/818HcwDkeHL.jpg) ## Customer Reviews ### ⭐⭐⭐⭐⭐ Good quality and well made *by on Reviewed in the United Kingdom 7 August 2025* They are great! ### ⭐⭐⭐⭐⭐ Worked a treat *by on Reviewed in the United Kingdom 13 January 2025* Bought to convert my old Ryobi 12V nicad battery to li-ion.Thoroughly recommended. There are 4 in the pack but only used 1 so now have a couple of spares should they be required.The batteries charged without issue and I now have electric start once again on my brush cutter ### ⭐⭐⭐⭐⭐ Good value for a 4 pack *by on Reviewed in the United Kingdom 7 March 2025* All working fine and charging as they should ## Frequently Bought Together - Youmile 4 pcs 3S 40A PCB Protection Board 18650 Lithium Battery Protection Board Li-ion Lithium Battery Charger PCB BMS 11.1V 12V 12.6V with Balance Charging with Nickel strip - Aideepen 3PCS 3S 20A Li-ion Lithium Battery Charger Board PCB BMS 12.6V Cell Module Overcharge Overcurrent Short Circuit Protection - Nickel Strip,0.15 * 27mm 10M 2P Nickel Strip for 18650 Battery Spot Welding Tape Ni Plate,Used for 2 Parallel 18650 Batteries Spot Welding DIY 18650 Battery Pack, 20.25mm Spacing --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.pt/products/568742880-4-pcs-3s-40a-pcb-protection-board-18650-lithium-battery](https://www.desertcart.pt/products/568742880-4-pcs-3s-40a-pcb-protection-board-18650-lithium-battery) --- *Product available on Desertcart Portugal* *Store origin: PT* *Last updated: 2026-09-22*