--- product_id: 257656207 title: "2Pack Enhanced 4S 40A 16.8V Li-ion Lithium Battery Protection Board PCB BMS Charger Protection Circuit Balance Charging Module for Drill Motor Motorcycle Battery (4S 40A)" brand: "atnsinc" price: "S/.64" currency: PEN in_stock: true reviews_count: 9 category: "Atnsinc" url: https://www.desertcart.pe/products/257656207-2pack-enhanced-4s-40a-16-8v-li-ion-lithium-battery store_origin: PE region: Peru --- # 40A continuous discharge current 16.8V max charging voltage Multi-layer battery protection 2Pack Enhanced 4S 40A 16.8V Li-ion Lithium Battery Protection Board PCB BMS Charger Protection Circuit Balance Charging Module for Drill Motor Motorcycle Battery (4S 40A) **Brand:** atnsinc **Price:** S/.64 **Availability:** βœ… In Stock ## Summary > πŸ› οΈ Power your projects with precision and protection β€” don’t get left behind! ## Quick Answers - **What is this?** 2Pack Enhanced 4S 40A 16.8V Li-ion Lithium Battery Protection Board PCB BMS Charger Protection Circuit Balance Charging Module for Drill Motor Motorcycle Battery (4S 40A) by atnsinc - **How much does it cost?** S/.64 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.pe](https://www.desertcart.pe/products/257656207-2pack-enhanced-4s-40a-16-8v-li-ion-lithium-battery) ## Best For - atnsinc enthusiasts ## Why This Product - Trusted atnsinc brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - β€’ **Powerhouse Performance:** Delivers a robust 40A continuous discharge current to keep your high-demand tools running smoothly. - β€’ **Versatile Compatibility:** Supports 4S lithium battery packs including 18650, 26650, and polymer cellsβ€”perfect for drills, motors, and motorcycles. - β€’ **Precision Voltage Control:** Maintains a stable 16.8V charging voltage with high-accuracy detection for optimal battery health. - β€’ **Comprehensive Safety Shield:** Built-in overcharge, over-discharge, and overcurrent protections safeguard your batteries and devices. - β€’ **Compact & Lightweight Design:** Slim 44x55x4mm profile fits seamlessly into your projects without adding bulk or weight. ## Overview This 2-pack Enhanced 4S 40A Li-ion Battery Protection Board offers a compact, high-performance solution for managing 4-series lithium battery packs up to 16.8V. Featuring a continuous 40A discharge current and multiple safety protections, it ensures stable, efficient charging and discharging for power tools, electric drills, and motorcycles. Designed for durability and precision, it supports various lithium cell types and optimizes battery lifespan while preventing damage from overcurrent, overcharge, and over-discharge. ## Description Product description Introduction Product Name: 4 string 14.8V 16.8V 40A lithium battery protection board Charging voltage: DC 16.8V~17V Continuous discharge current: 40A maximum (if the heat dissipation environment is not good, please reduce the load current) Continuous charging current: up to 20A Enhance Version Product size: 44*55*4mm Applicable choice: applicable to the nominal voltage of 3.7V, fully charged 4.2V lithium battery (including 18650, 26650, polymer lithium battery), can be drilled below 170W Notice Note 1: The successful start of the drill requires three 15C-20C power battery, or six 10C-15C power battery (ordinary 18650 can not start the drill!!). Note 2: strictly according to map wiring 0V, 4.2V, 8.4V, 12.6V, 16.8V, do not deliberately short circuit. Note 3: When the load of the brush motor is used, try to connect a non-polar capacitor (withstand voltage above 25V, capacity 10uF-100uF) to the motor's positive and negative terminals to prevent the reverse spike from the motor. Break the MOS tube. Note 4: 4 groups of batteries in series, please ensure that the voltage of each group of batteries, if not the same, please fill each battery separately and then use in series. The The Discharge test, the voltage drop faster battery that group is poor battery. Discharge diagram The RIGHT figure shows the module discharge diagram. The battery is 4 strings. The connected battery needs to meet the 40A discharge current. It can be realized by paralleling the battery or purchasing a battery with a large discharge current. For example, the battery 2000mAH, the discharge multiple 10C, then only need 4 series 2 and the maximum current can reach the discharge current 40A, stable discharge requires 4 strings 4 and can be, and need to pay attention to heat dissipation, the discharge battery power will drop rapidly. Charging diagram The LEFT picture shows the battery charging diagram, 4 series of batteries, the actual full charge, voltage 16.8V, charging voltage DC17V-18V, charging current depends on the battery connected, the maximum does not exceed 20A. Review: Works well - Works well, used 4 x 18650 li-ion cells together for a drill. The two boards were connected together on arrival but easily split apart by bending slightly. Installed in my drill and charged up to full power. Tested the drill, it works fine, have not used it for any projects yet though. Will update review if have any problems. Review: You guys are great - Exceptional value and service. Thank you ## Features - High Quality; Compact size and lightweight;High-accuracy voltage detection circuit; fine workmanship and durable; stable performance. - Multiple Protections: Over-discharge protection, overcurrent protection, overcharge protection; High charge and discharge current - LOW STANDBY CURRENT: MOS transistor can control the battery charge and discharge, low standby current consumption. - Applications:It is suitable for lithium batteries with nominal voltage of 3.7V and full voltage of 4.2V (including 18650, 26650, polymer lithium batteries, no size limit).Besides, it can use for electric drill with starting current below 80A and power below 135W . - If you want to start the drill successfully, it requires 3pcs15C-20C power batteries, or 6pcs10C-15C power batteries (Note: ordinary 18650 battery can not start the drill!! Recommended power battery models: VTC4, VTC4A, VTC5A, VTC6). About connecting cables, we suggest using more than 3 square millimeters copper wire. ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B08NJTS9DV | | Amperage | 40 Amps | | Best Sellers Rank | #311,441 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #1,328 in Power Converters | | Brand | ATNSINC | | Color | 4S 40A | | Current Rating | 40 Amps | | Customer Reviews | 4.1 out of 5 stars 84 Reviews | | Input Voltage | 240 Volts | | Item Weight | 0.02 Kilograms | | Manufacturer | Atnsinc | | Mfr Part Number | 19075 | | Model Number | 19075 | | Number of Ports | 2 | | Output Voltage | 16.8 Volts (DC) | | UPC | 701715452138 | ## Product Details - **Brand:** ATNSINC - **Color:** 4S 40A - **Input Voltage:** 240 Volts - **Item Weight:** 0.02 Kilograms - **Output Voltage:** 16.8 Volts (DC) ## Images ![2Pack Enhanced 4S 40A 16.8V Li-ion Lithium Battery Protection Board PCB BMS Charger Protection Circuit Balance Charging Module for Drill Motor Motorcycle Battery (4S 40A) - Image 1](https://m.media-amazon.com/images/I/81dmucJUzdL.jpg) ## Customer Reviews ### ⭐⭐⭐⭐⭐ Works well *by B***R on July 6, 2022* Works well, used 4 x 18650 li-ion cells together for a drill. The two boards were connected together on arrival but easily split apart by bending slightly. Installed in my drill and charged up to full power. Tested the drill, it works fine, have not used it for any projects yet though. Will update review if have any problems. ### ⭐⭐⭐⭐⭐ You guys are great *by T***L on November 11, 2021* Exceptional value and service. Thank you ### ⭐⭐⭐⭐ good less expensive BMS *by W***E on April 17, 2023* Needs better instruction on how to connect it up. Made mistakes and blew two boards. Seems to work okay when connected properly. ## Frequently Bought Together - 2Pack Enhanced 4S 40A 16.8V Li-ion Lithium Battery Protection Board PCB BMS Charger Protection Circuit Balance Charging Module for Drill Motor Motorcycle Battery (4S 40A) - 2Pcs 3S 11.1V 12.6V 25A W/Balance 18650 Li ion Lithium Battery PCB Protection Board - SHONAN Pure Nickel Strip 99.6% Nickel, 2 Inches Nickel Strips, 0.15x6x50mm Soldering Tabs for High Capacity 18650 Lithium Battery Pack, Li-Po, NiMh and NiCd Battery Pack and Spot Welding, 50 Pcs --- ## Why Shop on Desertcart? - πŸ›’ **Trusted by 1.3+ Million Shoppers** β€” Serving international shoppers since 2016 - 🌍 **Shop Globally** β€” Access 737+ million products across 21 categories - πŸ’° **No Hidden Fees** β€” All customs, duties, and taxes included in the price - πŸ”„ **15-Day Free Returns** β€” Hassle-free returns (30 days for PRO members) - πŸ”’ **Secure Payments** β€” Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** β€” Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.pe/products/257656207-2pack-enhanced-4s-40a-16-8v-li-ion-lithium-battery](https://www.desertcart.pe/products/257656207-2pack-enhanced-4s-40a-16-8v-li-ion-lithium-battery) --- *Product available on Desertcart Peru* *Store origin: PE* *Last updated: 2026-07-06*