Key Features
- 3500mAh High Capacity: The LG MJ1 is one of the most respected high-capacity 18650 cells available — 3500mAh of genuine LG Chem capacity in a protected button top format ready to drop into compatible devices.
- 10A Maximum Continuous Discharge: 10A continuous gives this cell enough current headroom for a wide range of flashlights, electronics, and single-cell devices without breaking a sweat.
- PCB Protection Circuit: Built-in protection covers overcharge, over-discharge, over-current, and short circuit — so you can use it in compatible devices without worrying about cell-level failures.
- Button Top Terminal: Positive button top for broad device compatibility — just keep in mind this cell is longer than a standard flat top unprotected 18650, so check your device's battery compartment dimensions before ordering.
- Original LG MJ1 Cell Base: This is a genuine LG Chem MJ1 flat top cell with a button top and PCB added by a third-party manufacturer — you get the real cell with added protection and button top convenience.
Note: This is a button top protected 18650 battery which is longer than a standard flat top unprotected 18650 battery.
Overview
The LG MJ1 has long been a favorite in the 18650 world for its combination of high capacity and reliable chemistry, and this protected button top version makes it accessible for devices that need button top format with built-in cell protection. Starting from the authentic LG Chem MJ1 flat top cell, a third-party manufacturer adds a button top terminal and PCB protection circuit covering overcharge, over-discharge, over-current, and short circuit — giving you cell-level protection without needing an external BMS. At 3500mAh and 10A continuous discharge, it handles everything from high-performance flashlights to single-cell electronics with plenty of capacity to spare. One thing to know before you order: the added button top and PCB make this cell physically longer than a standard flat top unprotected 18650 — measure your device's battery compartment and confirm the fit first.
Applications / Uses
- High-capacity flashlights and portable lighting designed for protected button top 18650 cells
- Consumer electronics, personal devices, and everyday carry gear requiring button top 18650 format
- Portable power banks and single-cell devices where built-in PCB protection adds essential safety
- Medical and industrial handheld equipment requiring long-runtime protected lithium-ion power
- Button top 18650 replacements where 3500mAh capacity and protection circuit are both a requirement
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 or box.
- 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 use in devices such as e-cigarettes or vaporizers.
-
What is Thermal Runaway?
- A dangerous chain reaction where heat generated by a failing battery causes it to overheat further, potentially leading to fire or explosion.
- Causes: Overcharging, short circuits, physical damage, or exposure to high temperatures.
- Prevention: Use a smart charger, avoid physical damage, and store batteries in a cool, dry place.
- Storage & Transport: Always store batteries in protective cases or boxes 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. These are signs of internal damage or instability, and continued use could result in failure, fire, or explosion.
- Charging: Use a smart charger designed specifically for lithium-ion batteries and ensure that the charger's voltage matches the battery's specifications. Never overcharge, over-discharge, or leave unattended while charging.
- Prohibited Activities: Do not short circuit, modify, puncture, crush, expose to liquids, or solder directly onto the battery (spot weld only).
- Emergency Response: If a cell shows signs of thermal runaway (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 combustibles. Lithium-ion cell fires are Class B fires — use an ABC/dry-chemical extinguisher, or douse with large amounts of water to cool the cell and prevent spread. 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 for lithium-metal batteries, not lithium-ion.) For any fire beyond a single small cell, evacuate and call emergency services.
Disclaimer
IMR Batteries 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 product warnings and safety guidelines are effectively communicated to their customers. Some cells are sold in bulk packaging and are not individually packaged. Resellers must provide appropriate packaging for each individual cell sold and must not distribute cells loose, unprotected, or without a proper storage box or case.
Product compatibility is the sole responsibility of the customer. IMR Batteries does not guarantee compatibility with any specific device or application. We are not responsible for the design, assembly, performance, or safety of any battery pack constructed using our cells. It is the customer’s responsibility to ensure proper cell matching, protection circuitry, configuration, and safe construction practices. Users and resellers assume full responsibility for the safe handling, usage, and distribution of this product.