18650 Battery Holder (2-Cell) – Open Sled (7.4V Output)

18650 Battery Holder (2-Cell) – Open Sled

The open-sled 2-Cell 18650 Battery Holder is the standard, no-nonsense power solution for robotics and DIY electronics. By connecting two 18650 lithium-ion cells in series, this holder delivers a nominal 7.4V output. Its lidless, open-face design allows for rapid battery swapping during intensive prototyping and testing sessions, ensuring your project never stays powered down for long.

Why choose this holder?

• Rapid Swapping: No lids, sliding covers, or screws to deal with. Simply pop depleted batteries out and snap fresh ones in instantly.
• Pre-wired Series Connection: Outputs exactly 7.4V (up to 8.4V fully charged), which is the ideal voltage for motor drivers like the L298N and for powering the Arduino’s VIN pin.
• Easy Chassis Mounting: Features pre-drilled mounting holes in the base, making it simple to screw directly onto your acrylic or 3D-printed robot chassis securely.

Common Applications

• Main power supply for 2WD and 4WD Mobile Robots
• Arduino and ESP32 project power source
• Custom 7.4V LED Lighting Arrays
• Benchtop breadboard prototyping

Technical Specifications

Feature	Specification
Battery Compatibility	2x 18650 Li-Ion Cells
Wiring Configuration	Series Connection
Output Voltage	7.4V Nominal (8.4V Peak)
Dimensions	76mm (L) x 40mm (W) x 19mm (H)
Output Wires	~ 15cm (Red + / Black -)
Material	ABS Plastic Base with Metal Coil Springs

Common Questions

How do I attach it to my robot?

There are two mounting holes located in the center of the plastic base. You can use standard M3 screws (or similar) to mount it directly to your chassis, or simply use strong double-sided foam tape for a quicker installation.

Why isn’t my circuit getting power?

Verify your battery polarity! In a series holder like this, the batteries must face opposite directions. The flat, negative end of the battery always rests against the metal spring.

Can I charge the batteries while they are in this holder?

No. This is a basic sled without a built-in Battery Management System (BMS). You must remove the batteries to charge them safely in an external wall charger, or wire a 2S BMS board to the output leads.

Does it fit “Protected” 18650 cells?

Protected cells have an extra circuit board attached, making them slightly longer (up to 69mm) than standard unprotected cells (65mm). While they can technically be forced in, it will be a very tight fit and may over-compress the springs. Standard unprotected cells are highly recommended.