Rechargeable Li-ion Battery 18650 4000 mAh 3.6V, No name ARB-L18 (039-625)

Rechargeable Li-ion Battery 18650 4000 mAh 3.6V No name ARB-L18 is a single-cell 18650-format lithium-ion cell offering a nominal capacity of 4000 mAh and a nominal voltage of 3.6 V. It is designed for devices and projects that require a compact, high-capacity cylindrical cell. The cell is intended to be used with a compatible charger and, when assembled into multi-cell packs, with appropriate protection and balancing circuitry to ensure safe operation.

Advantages

The 18650 4000 mAh cell provides extended run time compared with lower-capacity 18650 cells while maintaining standard dimensions for broad device compatibility. Its nominal 3.6 V voltage makes it suitable for many portable electronics and flashlight designs that accept a single 18650 cell. The cell’s high capacity is useful for reducing the frequency of charging in everyday use or in DIY battery pack applications where energy density is important.

Suitable for

• Flashlights and torches that accept 18650 cells
• Power banks and portable charging devices (with proper battery management)
• Portable electronics and gadgets designed for single 18650 cells
• DIY battery packs and custom power solutions (use with protection circuitry)
• Hobbyist and maker applications requiring high-capacity cylindrical cells

Key specifications

• Cell type: Lithium-ion (Li-ion), cylindrical 18650 format
• Nominal capacity: 4000 mAh
• Nominal voltage: 3.6 V
• Typical uses: single-cell devices, multi-cell packs with protection
• Form factor: 18 mm diameter × 65 mm length (standard 18650 dimensions)

How to use

Use the cell in devices that explicitly support 18650 lithium-ion batteries and match the nominal voltage and dimensions. Charge the cell only with a charger that is compatible with lithium-ion chemistry and the 18650 form factor; follow charger manufacturer instructions. When assembling two or more cells into a multi-cell pack, always include appropriate battery protection, balance charging, and monitoring circuitry to prevent overcharge, over-discharge, and cell imbalance. Insert the cell with correct polarity and ensure secure mechanical and electrical connections in holders or battery packs.

Usage recommendations

Store and operate the battery within manufacturer-recommended temperature ranges for lithium-ion cells. Avoid deep discharges and prolonged storage at full charge. Replace the cell if it shows signs of physical damage, swelling, excessive heating, or a significant drop in capacity. For safety and performance, use a dedicated Li-ion charger and, for multi-cell configurations, a proper protection circuit module (PCM) or battery management system (BMS).