1 cell 21700 lithium battery pack with wire, open type

Product Name: 1-cell 21700 Lithium Battery Holder (with Wires, Open Type)

Appearance and Structural Features:
Overall Structure: This is a slender black single-cell battery holder designed specifically for accommodating a 21700 lithium battery (diameter 21mm, length 70mm). It features a single-cell direct-insert layout, making it a narrow and elongated shape that fits easily into tight spaces.

Materials and Manufacturing:
Shell: The main body is made of black engineering plastic (usually PP or ABS) with a matte finish, providing good insulation and impact resistance.
Contacts: One end has a highly elastic nickel-plated coil spring (negative terminal), while the other end is a metal spring/contact (positive terminal), ensuring secure battery contact and reliable conductivity.

Functional Design (Key Features):
Wired Output: Red (positive) and black (negative) wires are led out from both ends, with the ends pre-stripped for easy direct welding or crimping of terminals, eliminating the need for secondary processing on the battery holder.
Mounting Holes: Circular screw mounting holes are provided on the side and bottom of the holder, allowing for secure fixation of the holder to a device's base plate or bracket to prevent displacement during use.
Polarity Marking: The positive and negative terminals are clearly marked with ⊕ / ⊖ symbols inside the holder to prevent incorrect battery installation.
Open Design: It's an open-type structure and typically needs to be used in conjunction with a device's enclosure, which provides protection and battery fixation.

Dimension Specifications (Based on Image Labels):
Total Length: Approximately 85.5mm
Width/Height: Approximately 21.7mm
End Width: Approximately 23.8mm
Electrical Characteristics: A single 21700 lithium battery typically has a nominal voltage of 3.6V / 3.7V (about 4.2V when fully charged) and a capacity generally ranging from 4000–5000mAh, making it suitable for medium to high discharge demand scenarios.