HONGLI IMR 18650 1800mAh 3.7V Rechargeable Lithium-Ion Cell

1. Product Overview

The HONGLI IMR 18650 is a rechargeable cylindrical lithium-ion cell with a nominal voltage of 3.7V and a rated capacity of 1800mAh.

Its energy rating of 6.66Wh is consistent with the marked voltage and capacity:

3.7V × 1.8Ah = 6.66Wh

The cell can be used individually or combined in series and parallel arrangements to build compatible lithium-ion battery packs. The final pack voltage depends on the number of cells connected in series, while the total capacity depends on the number connected in parallel.

This is a loose rechargeable cell intended for battery-pack assembly. A suitable BMS, charger, insulation and mechanical enclosure must be selected separately.

2. Technical Specifications

Any charging, discharging, temperature or cycle-life value not printed on the cell should be confirmed from the manufacturer’s datasheet before use.

3. Capacity and Energy

The cell is marked with:

• Rated capacity: 1800mAh or 1.8Ah
• Nominal voltage: 3.7V
• Rated energy: 6.66Wh

The actual usable capacity can vary with:

• Discharge current
• Cut-off voltage
• Operating temperature
• Cell age
• Charging method
• Storage conditions
• Condition and authenticity of the cell

A capacity test should be performed before assembling the cells into a battery pack, especially when using cells from different production batches.

4. Battery-Pack Configurations

Compatible cells may be connected in different arrangements depending on the required voltage and capacity.

These values are theoretical. Actual pack capacity and usable energy depend on cell matching, discharge rate, BMS settings, temperature and pack construction.

5. Suitable Applications

This cell may be suitable for compatible low- or moderate-current applications such as:

• Rechargeable LED lights
• Emergency lights
• Portable electronic equipment
• Bluetooth speakers
• Small backup-power devices
• DIY electronics projects
• Battery repair and replacement
• Low-power instruments
• Custom rechargeable battery packs
• Educational and prototype projects

Do not use this cell for power tools, high-performance electric vehicles, high-current motors or other demanding loads unless its continuous and peak discharge-current ratings are verified from an authentic manufacturer datasheet.

6. Charger and BMS Compatibility

Use this cell only with charging and protection equipment designed for 3.6V or 3.7V nominal lithium-ion cells.

For a single cell:

• Use a proper single-cell lithium-ion CC/CV charger.
• The typical maximum charging voltage is 4.2V.
• Do not use a charger designed only for LiFePO₄ cells.
• Do not use a lead-acid battery charger.

For a multi-cell battery pack:

• Use a BMS matching the exact number of series groups.
• Use a lithium-ion charger matching the pack’s maximum charging voltage.
• Select the BMS current rating according to the verified cell current and load requirement.
• Connect all balance wires in the correct sequence.
• Use closely matched cells from the same model and production batch.

7. Battery-Pack Assembly Guidance

• Check the voltage of every cell before assembly.
• Perform capacity and internal-resistance testing when possible.
• Use cells with closely matched voltage, capacity and internal resistance.
• Inspect the wrapper and terminal insulation ring for damage.
• Replace damaged insulation before using the cell.
• Maintain the correct polarity throughout assembly.
• Use correctly sized cell holders or spacers.
• Use suitable pure-nickel strips or properly rated busbars.
• Prefer spot welding instead of soldering directly to the cell.
• Keep the positive terminal properly insulated.
• Connect a compatible BMS before operating a multi-cell pack.
• Add a suitable fuse where required.
• Insulate all nickel strips, busbars and exposed electrical connections.
• Secure the cells against vibration and movement.
• Enclose the completed pack in an appropriate protective covering or case.

8. Important Current-Rating Note

The cell’s continuous and maximum discharge-current ratings are not visible in the supplied image.

Do not estimate the safe current only from the 18650 size, IMR marking or 1800mAh capacity. Different 18650 cells can have significantly different current capabilities.

Until the manufacturer’s datasheet is verified, this cell should not be advertised or used as a high-drain cell.

The safe current of a complete battery pack is determined by the lowest-rated component, including:

• Battery cells
• BMS
• Nickel strips or busbars
• Power cables
• Connectors
• Fuse
• Charger
• Connected load

9. Safety Information

• Use only a compatible lithium-ion charger.
• Do not charge above the manufacturer’s specified voltage.
• Do not reverse the cell polarity.
• Never short-circuit the positive and negative terminals.
• Do not puncture, crush, bend or dismantle the cell.
• Do not expose the cell to fire, excessive heat or direct sunlight.
• Do not use a cell with a torn wrapper or damaged insulation ring.
• Do not combine cells of different models, capacities, ages or conditions in one pack.
• Do not use swollen, leaking, corroded or unusually hot cells.
• Stop charging or discharging if the cell becomes excessively hot.
• Store the cell in a dry, non-conductive container away from loose metal objects.
• Keep cells away from children.
• Battery-pack assembly should be performed by someone familiar with lithium-ion battery safety.