ASOL 303030 3.7V 250mAh Lithium Polymer Battery Cell

Lithium PolymerUN38.3

The ASOL 303030 is an ultra-thin 3.7V 250mAh Lithium Polymer battery (0.925Wh) in a 1S1P soft-pouch cell configuration, with a 3.1 x 30.5 x 32.5 mm footprint that fits the smallest wearable housings. Purpose-built for TWS earbud cases, item finders, smart watches, mini GPS trackers and smart rings. Full OEM & ODM - tabs, wire length, connector and PCM all configurable.

Key SpecPrecise Specification
Model No.ASOL 303030
Core Electrical Specs3.7V · 250mAh · 0.925Wh
Cell Configuration1S1P Lithium Polymer soft pouch
Discharge Performance50mA (0.2C) standard · 250mA (1C) max continuous
Protection SystemOptional PCM/PCB (over-charge / over-discharge)
Cycle Life≥500 cycles (100% DOD, 0.2C, 25°C)
Cell Size & Weight3.1 x 30.5 x 32.5 mm · ~5.5g
Standard ConnectorWire leads, customizable
Compliance & CertificationsUN38.3
Est. 2020 50+ Countries 2 Facilities OEM & ODMProject Review
Lithium PolymerRechargeable lithium
UN38.3Certified & tested
OEM / ODMFactory-direct maker
Custom-builtCapacity · voltage · connector
WorldwideShipping & support

ASOL 303030 3.7V 250mAh Lithium Polymer battery infographic — TWS earbud cases and item finders

ASOL 303030 Lithium Polymer Battery — A 250mAh ultra-compact soft-pack Lithium Polymer delivering 0.925Wh energy in an ultra-ultra-thin 3.1mm profile. At only 30.5×32.5mm in footprint, this is ASOL’s smallest standard battery — engineered for next-generation miniaturized wearables and ultra-compact electronics: TWS earbuds charging cases, Bluetooth item finders, smart watches, mini GPS trackers, and smart rings.


Why Lithium Polymer vs Coin Cell?

  • Ultra-Ultra-Thin 3.1mm — Thinner than standard thin batteries; fits the most space-constrained in-ear and wearable enclosures
  • Compact 30.5×32.5mm Footprint — Among ASOL’s smallest standard cells by footprint area
  • 250mAh in Micro Package — 4× the capacity of a typical CR1220 coin cell (≥5mAh)
  • 1C Balanced Power — 250mA continuous delivery suits ultra-compact device load profiles
  • Featherweight Soft Pack — Aluminum-laminated construction minimizes device weight
  • Flexible Integration — Adapts to irregular and curved enclosures common in wearables
  • OEM-Friendly — Custom tabs, wires, connectors, and PCM available

Key Features

Tiny cell, dependable power

250mAh / 0.925Wh Compact Power

High energy density in ASOL’s smallest form factor.

Ultra-Ultra-Thin 3.1mm Profile

Fits the thinnest in-ear and wearable enclosures.

Compact 30.5×32.5mm Footprint

Among the smallest standard ASOL cells.

250mA Max 1C Discharge

Continuous power delivery for micro devices.

≥500 Cycle Life

Reliable long-term performance with minimal degradation.

Wide Temperature Range

Discharge −20–60°C, charge 0–45°C.

UN38.3 Certified

Safe for global air transport.

OEM/ODM Ready

Custom tabs, wires, connectors, protection circuits.


Specifications

Parameter Value
Model 303030
Chemistry Lithium Polymer (Lithium Polymer) Soft Pack
Nominal Voltage 3.7V
Nominal Capacity 250mAh
Nominal Energy 0.925Wh
Dimensions (T×W×H) 3.1×30.5×32.5mm
Charge Voltage 4.2V
Standard Charge Current 50mA (0.2C)
Max Charge Current 250mA (1C)
Standard Discharge Current 50mA (0.2C)
Max Discharge Current 250mA (1C, continuous)
Charge Cut-off 4.2V
Discharge Cut-off 2.5V
Charge Temperature 0~45°C
Discharge Temperature -20~60°C
Storage Temperature -20~45°C (recommended)
Cycle Life ≥500 cycles (100% DOD, 0.2C, 25°C)
Weight (Approx.) ~5.5g
Certifications UN38.3

Applications

Where the 303030 is used

TWS Earbuds Case

3.1mm thin fits charging cases · 2-3 full earbud recharges.

Bluetooth Item Finder

Slim key & item tags · 6-2 months beacon standby.

Smart Watch & Band

Slim wearable fit · 1-2 days heart-rate & notifications.

Mini GPS Tracker

Discreet pet & asset trackers · 1-2 days GPS standby.

Smart Ring

Ultra-thin ring fit · 1-2 days fitness & sleep tracking.


Why ASOL

Factory-direct, fully customizable

Flexible OEM / ODM

Connector, wire gauge, heat-shrink color, custom brand label, BMS & housing.

Proven protection

Integrated PCB against overcharge, over-discharge, overcurrent & short circuit.

Consistent cell quality

Grade-A cells, voltage-matched ±10mV for stable, reliable performance.

Project review

Sample evaluation may be available for selected cylindrical and lithium polymer battery projects, subject to specification review and product availability. Sample freight is paid by the customer.

Quality Control

Inspection requirements and acceptance criteria are confirmed for each project before order release.

Global shipping

UN38.3 Class 9 air & sea · DHL/FedEx/UPS · EXW/FOB/CIF/DDP.

Wholesale Pricing

Quantity Unit Price Savings
100-499 pcs Contact us -
500-999 pcs Contact us 8% off
1,000-4,999 pcs Contact us 15% off
5,000+ pcs Contact us 20%+ off

Wholesale Note: Custom specifications are welcome. Sample evaluation may be available for selected cylindrical and lithium polymer battery projects, subject to specification review and product availability. Sample freight is paid by the customer. Full certification documentation provided with shipment.

Frequently Asked Questions

What are the key specifications of the ASOL 303030 3.7V 250mAh Lithium Polymer Battery Cell?

The ASOL 303030 3.7V 250mAh Lithium Polymer Battery Cell is a 3.7V 250mAh lithium battery, measuring 3.1×30.5×32.5mm, weighing ~5.5g.

What is the maximum discharge current of the ASOL 303030 3.7V 250mAh Lithium Polymer Battery Cell?

The ASOL 303030 3.7V 250mAh Lithium Polymer Battery Cell supports a maximum continuous discharge current of 250mA.

How many charge cycles does the ASOL 303030 3.7V 250mAh Lithium Polymer Battery Cell last?

The ASOL 303030 3.7V 250mAh Lithium Polymer Battery Cell is rated for ≥500 cycles, retaining strong capacity across its service life.

What safety certifications does the ASOL 303030 3.7V 250mAh Lithium Polymer Battery Cell have?

It is certified to UN38.3, and full test reports can be provided on request.

Does ASOL offer OEM/ODM customization for the ASOL 303030 3.7V 250mAh Lithium Polymer Battery Cell?

Yes. As a lithium battery manufacturer, ASOL provides full OEM/ODM customization — capacity, voltage, cell configuration, connector type, wire length, and label printing can all be tailored to your application and order volume.

Can I get a sample or a quote for the ASOL 303030 3.7V 250mAh Lithium Polymer Battery Cell?

Yes. Sample evaluation may be available for selected cylindrical and lithium polymer battery projects, subject to specification review and product availability. Sample freight is paid by the customer. Email info@asolbattery.com or message +86 15779858703 on WhatsApp for a quote — ASOL typically responds within 24 hours on working days.


Contact Us

Channel Information
Email info@asolbattery.com
WhatsApp +86 157 7985 8703
Website www.asolbattery.com
Response Time Within 24 hours on working days

Need a different size or capacity? Explore ASOL’s full lithium polymer battery range

Project Inquiry

Send Us Your Battery Requirements

For a faster and more accurate quotation, please provide the key details below.
ASOL will recommend a suitable lithium battery solution based on your application, voltage, capacity, size and connector requirements.

Target Voltage3.7V, 7.4V, 12.8V, 24V, 48V or custom voltage
CapacityRequired Ah / Wh or expected runtime
Size / Dimension RequirementBattery size, device space or housing limit
ApplicationDevice type, working current and usage environment
QuantityEligible sample project, pilot run or batch production
Connector / Wire RequirementConnector model, wire length and polarity
OEM / Branding RequestLogo, label, casing or packaging request
Destination CountryShipping country and required documents

ASOL will review your requirements and reply with a suitable battery solution.

Shenzhen Asol Battery Tech Co., Ltd. (ASOL)

Assembly, production and global distribution of advanced lithium battery solutions, including custom lithium-ion and LiFePO4 battery packs, lead-acid replacement batteries and OEM/ODM battery solutions for B2B clients worldwide.

Connect With Us

Contact & Trust

  • Manufacturer: Shenzhen Asol Battery Tech Co., Ltd.
  • Location: Qingxi Town, Dongguan, Guangdong, China
  • Email: info@asolbattery.com
  • Tel: +86 157 7985 8703
  • Service: OEM/ODM lithium battery pack solutions

ASOL focuses on lithium battery packs, LiFePO4 lead-acid replacement batteries and OEM/ODM battery solutions, with support for BMS/PCM matching, wiring, connectors, labeling and worldwide B2B supply.

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