<h2>10-Pack 18650 Li-Ion Battery Protection Boards – 3.7V, 28×3mm</h2> <p>Keep your 3.7V 18650 lithium-ion batteries safe and performing at their best with this set of 10 precision protection circuit boards. Each board is engineered with a high-quality integrated circuit to guard against overcharging, over-discharging, short circuits, and overcurrent — giving you peace of mind whether you're building DIY electronics, battery packs, or repair projects.</p> <h3>Key Features</h3> <ul> <li> <strong>4-in-1 Protection:</strong> Overcharge, over-discharge, short circuit, and overcurrent protection in a single compact board.</li> <li> <strong>Precision IC:</strong> Main IC uses imported precision components for stable, reliable performance.</li> <li> <strong>Low Current Consumption:</strong> Minimal standby draw ensures your battery retains its charge when not in use.</li> <li> <strong>Compact Design:</strong> Ultra-slim 28×3mm profile fits neatly inside 18650 battery housings.</li> <li> <strong>Solderable Tabs:</strong> Pre-fitted solder tabs make installation straightforward for DIY enthusiasts and technicians alike.</li> <li> <strong>Durable Build:</strong> Fine workmanship ensures consistent performance and long service life.</li> <li> <strong>Versatile Compatibility:</strong> Suitable for a wide range of 3.7V lithium-ion battery configurations and high-integration, low-cost applications.</li> </ul> <h3>Specifications</h3> <table style="width:100%; border-collapse:collapse;"> <tr style="background:#f5f5f5;"> <td style="padding:8px; border:1px solid #ddd;"><strong>Dimensions</strong></td> <td style="padding:8px; border:1px solid #ddd;">28 × 3mm (approx.)</td> </tr> <tr> <td style="padding:8px; border:1px solid #ddd;"><strong>Compatible Battery</strong></td> <td style="padding:8px; border:1px solid #ddd;">3.7V 18650 Li-Ion</td> </tr> <tr style="background:#f5f5f5;"> <td style="padding:8px; border:1px solid #ddd;"><strong>Overcharge Release Voltage</strong></td> <td style="padding:8px; border:1px solid #ddd;">4.275 ± 0.025V</td> </tr> <tr> <td style="padding:8px; border:1px solid #ddd;"><strong>Overcharging Voltage Range</strong></td> <td style="padding:8px; border:1px solid #ddd;">4.075 ± 0.025V</td> </tr> <tr style="background:#f5f5f5;"> <td style="padding:8px; border:1px solid #ddd;"><strong>Over-Discharge Voltage Range</strong></td> <td style="padding:8px; border:1px solid #ddd;">2.5 ± 0.1V</td> </tr> <tr> <td style="padding:8px; border:1px solid #ddd;"><strong>Overcurrent Detection</strong></td> <td style="padding:8px; border:1px solid #ddd;">2.8 ± 0.3A</td> </tr> <tr style="background:#f5f5f5;"> <td style="padding:8px; border:1px solid #ddd;"><strong>Material</strong></td> <td style="padding:8px; border:1px solid #ddd;">Carbide PCB</td> </tr> <tr> <td style="padding:8px; border:1px solid #ddd;"><strong>Package Quantity</strong></td> <td style="padding:8px; border:1px solid #ddd;">10 × Protection Boards</td> </tr> </table> <h3>Connection Guide</h3> <ul> <li> <strong>B+</strong> → Connect to Battery Positive (+)</li> <li> <strong>B−</strong> → Connect to Battery Negative (−)</li> <li> <strong>P+</strong> → Battery Output / Input Positive (+)</li> <li> <strong>P−</strong> → Battery Output / Input Negative (−)</li> </ul> <h3>Package Contents</h3> <ul> <li>10 × 18650 Li-Ion Battery Protection Boards</li> </ul> <p><strong>Made in Mainland China.</strong></p> <h3>Related Products You May Like</h3> <ul> <li><a href="/products/1-channel-relay-module-dc-3-3v-24v-optocoupler-arduino">1-Channel Relay Module DC 3.3V–24V Optocoupler for Arduino</a></li> <li><a href="/products/0-25mm-1000-turn-precision-copper-inductor-coil-diy-electronics">0.25mm 1000-Turn Precision Copper Inductor Coil for DIY Circuits</a></li> <li><a href="/products/1-channel-scr-solid-state-relay-switch-module-dc3-24v-40a-optocoupler">1-Channel SCR Solid State Relay Module DC3-24V 40A Optocoupler</a></li> </ul> <p>For