351626 3.8V 140mAh LiPo Battery

High Voltage. Micro Size. Maximum Energy Where Space is Zero.

The 351626 3.8V 140mAh HV Lithium Polymer Battery is engineered for the most space-constrained wearable devices on the market. Leveraging High Voltage LiPo (HV LiPo) technology with a 4.35V charge ceiling, this ultra-micro cell delivers 5~8% more energy than standard 3.7V cells of identical dimensions — packing more power into less space than ever before. Purpose-built for TWS earphones, ultra-slim smart watches, smart rings, and micro IoT devices where every cubic millimeter is precious.

⚠️ Important – High Voltage LiPo Notice

This is a 3.8V High Voltage LiPo (HV LiPo) cell with a charge cutoff voltage of 4.35V. It must be used with a charging circuit specifically designed for HV LiPo (4.35V cutoff). Do NOT use with standard 3.7V / 4.2V charging circuits — doing so may cause cell damage or safety hazards.

✅ Key Features

🔋 140mAh HV LiPo – More Energy, Same Footprint High Voltage LiPo technology delivers 140mAh / 0.53Wh from a 3.5×16×26mm micro cell — providing 5~8% more usable energy than standard 3.7V cells of the same physical dimensions. For ultra-compact devices where enlarging the battery compartment is not an option, the 351626 HV LiPo is the engineering solution that extends runtime without changing the design.

📐 Ultra-Micro Form Factor – 351626 (3.5 × 16 × 26mm) At just 3.5mm thin, 16×26mm footprint, and approximately 3g — the 351626 is among the smallest soft-pack LiPo cells available for wearable applications. Designed to fit into the tightest TWS earphone charging cases, micro smart watch bodies, smart ring cavities, and miniaturized IoT sensor enclosures with absolute precision.

🔬 HV LiPo Technology Advantage – Why 3.8V Beats 3.7V

🛡️ Built-in PCM Protection – HV-Optimized Safety High-performance Protection Circuit Module (PCM) specifically calibrated for 3.8V HV LiPo cell characteristics — providing precise overcharge protection at 4.35V alongside comprehensive over-discharge, overcurrent, and short circuit defense. Prevents over-voltage damage, swelling, and fire risk unique to high-voltage cell chemistry — ensuring safe, reliable operation in all micro wearable environments.

⚡ Stable High-Voltage Output – Precision Power for Micro Electronics Advanced high-voltage polymer electrolyte system maintains a flat, stable discharge curve from 4.35V down to 3.0V with minimal deviation — delivering consistent, clean power to TWS audio chips, smart watch processors, GPS modules, and IoT microcontrollers throughout the full discharge cycle. No signal drops. No audio artifacts. No brownouts.

🏋️ ~3g Near-Zero Weight – Invisible in Every Device At approximately 3g, the 351626 adds virtually undetectable weight to any wearable device — whether embedded in an earphone case, a watch body, or a smart ring. Enables product designers to achieve the lightest possible device weight without compromising on battery capacity or safety.

♻️ 500+ Cycle Life – Reliable Long-Term Performance Rated for over 500 full charge/discharge cycles with ultra-low self-discharge rate. Retains excellent capacity after extended storage — extending the service life of TWS earphones, smart watches, and wearable devices while reducing end-user replacement costs and supporting long-term brand loyalty.

🏆 Grade A Cells – Strictest ±8mAh Micro Consistency Every cell undergoes the most rigorous electrochemical performance testing protocol — with capacity variance controlled within ±8mAh, applying our strictest consistency standard specifically for ultra-small capacity cells. Uniform internal resistance across all production batches ensures every unit in every shipment performs identically.

🌍 CE Certified & Globally Compliant CE / UN38.3 / RoHS / MSDS / IEC62133 certified — fully compliant with EU market entry requirements and international air freight regulations. Complete documentation package available for seamless global customs clearance.

📦 In Stock – Ready for Immediate Dispatch Strong warehouse inventory available for fast fulfillment. Flexible order quantities from engineering prototype samples to mass production runs — with competitive lead times for the fast-moving wearable electronics market.

📦 Specifications

🔌 Compatible Applications

🔍 HV LiPo vs Standard LiPo — Ultra-Slim Series Full Comparison

✅ The 351626 HV LiPo is the only cell in this series offering High Voltage technology — delivering more energy per cubic millimeter than any standard LiPo alternative of the same size. The ideal choice when standard cells simply can’t fit more capacity.

📣 Why Choose Us?