---
product_id: 369297812
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$0"
currency: SGD
in_stock: false
url: https://www.desertcart.sg/products/369297812-2pack-enhanced-4s-40a-16-8v-li-ion-lithium-battery
store_origin: SG
region: Singapore
---

# 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$0
**Availability:** ❌ Out of Stock

## Summary

> 🛠️ Power your projects with precision and protection — never settle for less!

## 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$0 with free shipping
- **Is it available?** Currently out of stock
- **Where can I buy it?** [www.desertcart.sg](https://www.desertcart.sg/products/369297812-2pack-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

- • **Compact & Durable Design:** Lightweight, finely crafted PCB built to last and fit seamlessly into your battery pack.
- • **Precision Voltage Control:** Accurate voltage detection ensures safe charging up to 16.8V with overcharge and over-discharge safeguards.
- • **Powerhouse Current Handling:** Supports up to 40A continuous discharge for high-demand tools and motors.
- • **Universal Battery Compatibility:** Works flawlessly with 3.7V lithium cells including 18650, 26650, and polymer types—no size limits.
- • **Optimized for High-Performance Drills:** Perfect for electric drills under 135W, enabling smooth starts with recommended power batteries.

## Overview

This 2-pack 4S 40A Li-ion Battery Protection Board offers robust multi-protection circuitry including overcharge, over-discharge, and overcurrent safeguards. Designed for lithium batteries up to 16.8V, it supports continuous discharge currents up to 40A, making it ideal for electric drills and motors under 135W. Compact and durable, it ensures stable performance and compatibility with popular lithium cell formats like 18650 and 26650.

## Description

Specifications: Charging voltage:16.8v ~ 18.1vOver Charge voltage:4.25±0.05vOver Discharge voltage: 2.5v±0.05vContinuous discharge current (upper limit): 40A (if the heat dissipation environment is not good, please reduce the load current )Continuous charge current (upper limit): 20AInternal resistance: Less than 100mΩApplications: 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 .Note: 1.Do not deliberately make it short circuit.Please strictly according to the diagram wiring to avoid possible damage to the chip. (Connect wires refer to the "wiring diagram"(NO.5 picture).2.When the battery for the first time, do not connect any load or equipment to the output.After connection, it need to charge activation first, then will have the output.3.Do not mix good batteries with bad ones.4.The closer the internal resistance of the 4 battery capacities is the better.5.When using a brush motor type load, try to connect a non-polar capacitor (withstand voltage above 25V, capacity 10uF-100uF) in parallel with the positive and negative terminals of the motor to prevent the reverse spike voltage generated by the motor from interfering with the protection board or breakdown of the MOS tube.Package inlcudes: 2x 4S 40A lithium Battery Protection Board

## 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 |
|---------------|-------|
| Current Rating | 40 Amps |
| Input Voltage | 240 Volts |
| Output Voltage | 16.8 Volts (DC) |
| Item Weight | 0.02 Kilograms |
| Color | 4S 40A |

## Product Details

- **Brand:** Atnsinc
- **Colour:** 4S 40A
- **Item weight:** 0.02 Kilograms
- **Output voltage:** 16.8 Volts
- **Input voltage:** 18.1 Volts

## 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)
![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 2](https://m.media-amazon.com/images/I/71I3ie7E6vL.jpg)
![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 3](https://m.media-amazon.com/images/I/71KQ7XDIPCL.jpg)
![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 4](https://m.media-amazon.com/images/I/71nyhxpR+pL.jpg)
![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 5](https://m.media-amazon.com/images/I/711g+-5343L.jpg)

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*Product available on Desertcart Singapore*
*Store origin: SG*
*Last updated: 2026-01-24*