Key Features
- 3500mAh High Capacity: Built on the original LG Chem MJ1 18650 cell, delivering 3500mAh nominal capacity and 3.6V nominal voltage for extended runtime in compatible button top devices.
- 10A Maximum Continuous Discharge: Supports up to 10A continuous discharge for reliable, controlled current delivery in compatible single-cell and multi-cell device applications.
- PCB Protection Circuit: Third-party integrated protection circuit board provides overcharge, over-discharge, over-current, and short circuit protection for safe operation in compatible devices without an external BMS.
- Button Top Terminal: Positive button top configuration ensures broad compatibility with devices designed for button top 18650 cells — note that this cell is physically longer than a standard flat top unprotected 18650 battery.
- Original LG MJ1 Cell Base: Built on the authentic LG Chem MJ1 flat top cell with button top and PCB added by a third-party manufacturer, combining genuine LG cell quality with protected button top convenience.
Note: This is a button top protected 18650 battery which is longer than a standard flat top unprotected 18650 battery.
Overview
This LG MJ1 18650 Protected Button Top battery pairs the original LG Chem MJ1 flat top 18650 cell with a third-party added button top terminal and PCB protection circuit, creating a protected button top cell suited for compatible devices requiring both button top format and cell-level safety protection. With a nominal capacity of 3500mAh, a nominal voltage of 3.6V, and a maximum continuous discharge of 10A, this cell delivers strong runtime and reliable performance in single-cell and multi-cell device configurations. The integrated PCB protects against overcharge, over-discharge, over-current, and short circuit conditions without the need for an external Battery Management System. It is important to note that this protected button top cell is physically longer than a standard flat top unprotected 18650 battery due to its added button top terminal and protection circuit — always verify dimensional compatibility with your device before purchase. Do not remove the protective wrap, as doing so may compromise the protection circuit.
Applications / Uses
- High-capacity flashlights and portable lighting systems designed for protected button top 18650 cells
- Consumer electronics and personal devices requiring button top 18650 format with built-in cell-level protection
- Portable power banks and single-cell devices benefiting from PCB overcharge and over-discharge protection
- Medical and industrial handheld devices requiring stable, protected lithium-ion power with extended runtime
- Replacement cells for compatible button top 18650 devices where 3500mAh capacity and protection are both required
Specifications
| Brand: | LG Chem |
| Model: | MJ1 |
| Battery Type: | 18650 Lithium-Ion |
| Nominal Capacity: | 3500mAh |
| Nominal Voltage: | 3.6V |
| Maximum Voltage: | 4.2V |
| Max Continuous Discharge: | 10A |
| Protected: | Yes (PCB) — overcharge, over-discharge, over-current, short circuit |
| Battery Top: | Button Top |
| Approx. Dimensions: | 23.2mm x 69.3mm |
| Approx. Weight: | 48.8g |
This is a button top protected 18650 battery and is longer than a standard flat top unprotected 18650 battery. Please verify device compatibility before purchase.
⚠ Important Safety Warnings
Improper handling or misuse of this lithium-ion battery can result in FIRE, EXPLOSION, or THERMAL RUNAWAY, causing personal injury, property damage, or death. Users must read and follow all safety guidelines before purchase and use. Click here to review the full safety guidelines.
- Critical Warning: Never carry loose batteries in your pocket, purse, or bag. Loose batteries can come into contact with metal objects like keys or coins, causing a short circuit, which may result in severe burns, fire, or explosion. Always store or transport batteries in a protective case.
- Intended Use: This battery is designed for integration into protected battery packs with a Battery Management System (BMS) or Protection Circuit Board (PCB). It is not intended for standalone use or for e-cigarettes, vaporizers, or similar devices.
-
Thermal Runaway: A chain reaction where heat from a failing battery
causes further overheating, potentially leading to fire or explosion.
- Causes: Overcharging, short circuits, physical damage, or exposure to high temperatures.
- Prevention: Use a smart charger, avoid damage, and store batteries in a cool, dry place.
- Storage & Transport: Always store batteries in protective cases to prevent accidental contact with metal objects. Never store loose batteries in pockets, purses, bags, or near conductive materials.
- Inspection: Do not use if the PVC wrapper, terminal insulator, or casing is damaged, dented, leaking, or bulging. Continued use could result in failure, fire, or explosion.
- Charging: Use a smart charger specifically designed for lithium-ion batteries and ensure the charger's voltage matches the battery's specifications. Never overcharge, over-discharge, or leave unattended while charging.
-
Prohibited Activities:
- Do not expose the battery to extreme heat, fire, or liquids.
- Do not short circuit, puncture, crush, or modify the battery.
- Do not charge or discharge beyond the manufacturer’s voltage range.
- Do not dispose of in regular trash—always recycle at approved facilities.
- Emergency Response: If a cell shows signs of thermal runaway (e.g., smoke, swelling, hissing, or heat), stop use immediately and, if it can be done safely, move it to a non-flammable surface (e.g., concrete or sand) away from combustible materials. Lithium-ion cells burn as Class B fires — use an ABC / dry-chemical fire extinguisher, or douse with large amounts of water to cool the cell and prevent the fire from spreading. Do not rely on a small spray; thorough cooling is required, and cells can reignite from residual heat, so monitor the area afterward. (Class D extinguishers are intended for lithium-metal batteries, not lithium-ion.) For any fire beyond a single small cell, evacuate and call emergency services.
Disclaimer
18650Battery.com is not responsible for any damages, injuries, or claims arising from improper use, handling, or failure to follow these safety guidelines. Lithium-ion batteries require strict adherence to all safety protocols. It is the reseller's responsibility to ensure all safety warnings and product guidelines are effectively communicated to customers. Users and resellers assume full responsibility for the safe handling, usage, and distribution of this product.