Quality materials, flame retardant and temperature resistant, for safe use. temperature rating: designed for use at up to 235 C. Exceeding 235 C causes bubbling and prevents reflow soldering. DIY 18650 battery holder box: supports connections in series or parallel to meet your voltage and capacity needs. SMD goldplated 18650 battery box: available in 3slot and 4slot configurations for flexible cell arrangements. Reliable construction: optimized for hobbyist and prototyping applications with durable, solderfriendly design. Compatibility: specifically built for 18650 cells with standard dimensions and contact requirements. 23 practical use scenarios Portable power bank or multicell pack: assemble 3 or 4 x 18650 cells in a holder, wire in series for higher voltage or in parallel for increased capacity, and integrate into a compact power solution for onthego charging. RC devices and small electronics: create a compact multicell pack for remote control cars, drones, or other hobby electronics that require a stable, configurable battery source with low contact resistance. Solar storage or backup power: use as a modular battery holder within small solar projects or backup systems to store energy in a safe, flameretardant housing, with easy rerouting for different series/parallel configurations. Notes This holder is designed for use with up to 235 C environments; avoid higher temperatures to maintain integrity and solderability. The 3slot and 4slot variants provide flexible options for different 18650 cell quantities.