Before diving into performance metrics, compliance, or pack design, it’s essential to master the core concepts of lithium batteries—from chemistry to cell structure.
Whether you’re sourcing batteries for e-bikes, solar systems, or medical devices, understanding the basics helps you avoid common selection errors, communicate with engineers, and make informed decisions.
This page walks you through the core knowledge every professional buyer, engineer, or project manager should know, including battery types, cell structure, material composition, key terms, and typical misunderstandings. No deep BMS theory or testing protocols here—just the essential groundwork.
A lithium battery is a rechargeable energy storage device that uses lithium ions to move between the anode and cathode during charge and discharge cycles. It’s known for high energy density, low self-discharge, and long cycle life.
The three main types are cylindrical cells, prismatic cells, and pouch cells. Each type differs in structure, energy density, and suitability for specific applications like e-bikes, power tools, or storage systems.
Core materials include a positive electrode (cathode), negative electrode (anode), separator, electrolyte, and current collectors. These parts work together to enable the flow of lithium ions during operation.
Lithium ions move from the anode to the cathode during discharge and reverse during charging. This electrochemical process allows the battery to store and release energy efficiently.
Li-ion batteries have higher energy density but lower thermal stability. LiFePO₄ offers longer cycle life and greater safety, making it ideal for applications requiring high reliability.
Cylindrical cells offer excellent mechanical stability, efficient heat dissipation, and mature production processes. They’re commonly used in power tools, e-bikes, and energy storage packs.
Yes—when properly designed with quality materials and BMS protection. Certifications like UN38.3, CE, and UL also help ensure compliance and safety for transport and use.
Absolutely. Battery packs can be tailored with different cell formats, capacities, and configurations depending on your voltage, current, and space requirements.
A lithium battery is a device that stores electrical energy using lithium metal or lithium compounds. Understanding what a lithium battery cell is made of helps buyers assess whether a specific chemistry matches their application’s needs.
Broadly speaking, lithium batteries come in two categories:
Primary lithium batteries – Non-rechargeable, used in low-power devices.
Secondary lithium batteries – Rechargeable, including Li-ion and LiFePO₄ types. The difference between Li-ion and LiFePO4 lies in energy density, safety, and cycle life, making them suitable for different markets like EVs or solar storage.
ithium battery technology began in the 1970s. Sony introduced the first commercial lithium-ion battery in 1991. Today, lithium batteries are widely used in electric vehicles, energy storage, and consumer electronics.
Key Milestones:
1970s: First lithium metal batteries
1991: Sony launches Li-ion
2005–2020: Rise of EV and portable tech
2020+: Fast charging, solid-state innovation
Every battery pack is built from cells, and understanding their internal structure is key to understanding performance, safety, and lifespan.
Core components include:
Cathode (positive electrode) – Typically NCM, NCA, or LiFePO₄ materials.
Anode (negative electrode) – Usually graphite or lithium titanate (LTO).
Electrolyte – A liquid medium allowing lithium ions to move between electrodes.
Separator – A microporous film that prevents short circuits but lets ions pass through.
Shell/Casing – Determines the shape and some thermal behavior of the cell.
If you’re looking for common lithium battery types for e-bikes, you’ll likely encounter NCM, NCA, and LiFePO₄. Each type balances trade-offs between cost, energy output, charging speed, and safety.
| Cathode Material | Voltage | Energy Density | Charge/Discharge Performance | Cycle Life | Thermal Stability | Applications |
|---|---|---|---|---|---|---|
| Lithium Cobalt Oxide (LiCoO2) | Nominal 3.6V (Range 3.0–4.2V) | 150–240 Wh/kg | 0.7–1C, Max 2.5C, >1C shortens lifespan | 500–1000 (at standard depth of discharge) | 150°C (302°F): risk of thermal runaway | Phones, tablets, laptops, cameras, drones |
| Ternary Material (LiNiCoMnO2) | Nominal 3.7V (Range 3.0–4.2V) | 150–220 Wh/kg | 0.7–1C, Max 2.5–5C, 10C: 3.0Ah cell ~15s | 1000–2000 (at standard depth of discharge) | 210°C (410°F): stable | E-bikes, power tools, EVs, medical, industrial |
| Lithium Manganese Oxide (LiMn2O4) | Nominal 3.7V (Range 3.0–4.2V) | 100–150 Wh/kg | 0.5–1C, Max 2.5C, 10C: 3.0Ah cell ~15s | 300–700 (at standard depth of discharge) | 250°C (482°F): stable | EVs, power tools, low-cost equipment, seasonal storage |
| Lithium Iron Phosphate (LiFePO4) | Nominal 3.2V (Range 2.5–3.65V) | 90–120 Wh/kg | 1C typical, up to 30C (5s burst), fast charge/discharge | 2000+ (at standard depth of discharge) | 270°C (518°F): excellent stability | Energy storage systems, EVs, medical, industrial |
| Lithium Nickel Cobalt Aluminum Oxide (LiNiCoAlO2) | Nominal 3.6V (Range 3.0–4.2V) | 200–260 Wh/kg | 1C typical, Max 5C, charge cut-off voltage 4.2V | 500 (at standard depth of discharge) | 150°C (302°F): stable | High-energy EVs, drones, aerospace |
| Lithium Titanate (Li4Ti5O12) | Nominal 2.4V (Range 1.8–2.85V) | 50–80 Wh/kg | 1C typical, Max 5C, charge cut-off voltage 2.85V | 3000–7000 | Stable under 300°C (572°F) | UPS, power backup, solar storage, base station batteries |
Another point often misunderstood is the battery structure vs battery pack. A battery cell is a single energy unit, while a pack is a structured combination of cells plus BMS, wiring, and casing. Choosing the right structure depends on your form factor and power needs.
Cylindrical cells (e.g., 18650, 21700) – Highly standardized and mechanically robust.
Prismatic cells – Boxy format, easier for space-efficient pack design.
Pouch cells – Lightweight and compact, often used in consumer electronics.
Each format has unique trade-offs between energy density, durability, and manufacturability.
Learning how to read lithium battery specifications like voltage, capacity, and C-rate is essential for comparing suppliers. For example, energy (Wh) is calculated as voltage × capacity, while discharge rate (C rating) helps determine load capability.
Voltage (V) – Nominal voltage depends on chemistry (3.2V for LFP, 3.7V for NCM/NCA).
Capacity (mAh or Ah) – Indicates how much charge a battery can store.
Energy (Wh) – Calculated as Voltage × Capacity. Defines usable output.
Discharge Rate (C Rating) – The speed at which energy is released. 1C means full discharge in 1 hour.
Cycle Life – Number of full charge/discharge cycles before capacity drops below 80%.
Battery performance is tightly linked to the materials used in each part of the cell.
| Term | Definition |
|---|---|
| SOC | State of Charge – Current battery energy percentage |
| DOD | Depth of Discharge – How much energy is removed per cycle |
| BMS | Battery Management System – Protects and monitors the battery |
| Cycle Life | Number of full charge-discharge cycles |
| Self-discharge | Natural energy loss over time when idle |
Battery performance is tightly linked to the materials used in each part of the cell.
| Component | Material | Function |
|---|---|---|
| Cathode | NCM / NCA / LFP | Stores lithium ions; affects energy & safety |
| Anode | Graphite / LTO | Releases lithium ions during discharge |
| Electrolyte | Organic solvent + lithium salt | Medium for ion transfer |
| Separator | Microporous polyethylene or polypropylene | Prevents short circuit, allows ion flow |
Not always. You must balance size, discharge rate, and weight constraints.
Different chemistries serve very different purposes.
Without BMS, lithium batteries can overheat, swell, or even catch fire.
By understanding what lithium batteries are made of, how they function, and how different chemistries compare, you’re now better prepared to read specs, compare suppliers, and make informed buying decisions. This chapter lays the groundwork for exploring advanced topics like battery pack design, thermal management, BMS architecture, and international certification in future sections.
In the lithium battery industry, quality control (QC) isn’t just a process—it’s a buyer’s safeguard. Poor battery quality can lead to overheating, swelling, shortened lifespan, or even serious safety hazards. For B2B buyers—especially those in Europe, North America, and industrial sectors—QC is tied to brand reputation, compliance, and customer trust.
At Junda, we treat every battery pack as a mission-critical component. That’s why we implement a multi-stage QC system—from cell inspection to final pre-shipment tests—ensuring that every battery delivered meets international safety, performance, and traceability standards.
Key benefits of strict QC include:
Reduced risk of product recall or failure in the field
Improved consistency across batches and production lines
Increased trust from partners, resellers, and certification bodies
Compliance with regulatory standards like UN38.3, IEC 62133, and ISO 9001
| Certification | Purpose | Main Market | Applies To |
|---|---|---|---|
| UN38.3 | Ensures safe transport of lithium batteries by air/sea | Global | All lithium batteries |
| IEC 62133 | Covers safety performance and structure of rechargeable cells | Global (esp. EU, Asia) | Rechargeable lithium batteries |
| CE | Complies with EU health, safety, and environmental laws | European Union | Electronic devices incl. battery packs |
| UL (e.g. UL2271) | Certifies safety for the U.S. market | United States | E-mobility, energy storage, tools |
| RoHS | Limits hazardous substances in electronics | EU, UK | Consumer and industrial electronics |
| MSDS / SDS | Chemical composition and safe handling info | Global | All chemical battery products |
Different countries and applications demand different sets of certifications.
Whether you’re exporting eBike batteries to Germany or energy storage packs to the U.S., it’s essential to match your battery certification set with the regulatory expectations of the destination market and the battery’s use case.
| Region | Battery Application | Recommended Certifications |
|---|---|---|
| EU | eBike, Energy Storage, Tools | CE, UN38.3, RoHS, IEC 62133, MSDS |
| United States | eBike, UPS, Power Tools | UL2271 / UL2580, UN38.3, MSDS |
| Middle East | Energy Storage, Solar Systems | UN38.3, IEC 62133, MSDS |
| Australia | ESS, Electric Vehicles, Telecom | UN38.3, CE, RoHS, MSDS |
| Global Transport | All lithium batteries | UN38.3, MSDS |
Uncertified batteries pose serious risks—not just to safety, but to your entire business.
Many buyers new to lithium battery sourcing underestimate the consequences of skipping certifications. But in regulated markets like the EU, USA, and Middle East, delivering a non-certified battery pack can lead to shipment detention, legal fines, denied customs clearance, or worse—fires and user injury.
🚫 Rejected Shipments: Customs may block or destroy uncertified batteries (especially without UN38.3 air shipment docs).
🚫 Legal Liability: Injuries or product failures may trigger lawsuits or warranty claims.
🚫 No Air Freight: Without UN38.3, MSDS, and packaging declarations, batteries cannot be shipped by air (IATA DGR rules).
🚫 Importer Blacklisting: Repeat non-compliance can place your company on customs watchlists.
🚫 Brand Damage: Even if your batteries perform well, lack of visible certifications undermines trust in tenders and B2B deals.
Certifying your battery pack is not just paperwork—it’s a proven process involving real testing, documentation, and technical compliance.
Here’s a simplified roadmap to help you navigate certification with confidence, whether you’re targeting CE, UL, or UN38.3:
Decide where the battery will be sold or shipped (EU, US, etc.), and determine which certifications are legally required (e.g., CE, UL, UN38.3).
Select an accredited third-party lab like SGS, TÜV Rheinland, CTI, or Intertek that has experience with lithium battery compliance testing.
Prepare required documents: circuit diagram, BMS specs, MSDS, cell datasheets, mechanical design drawings, label mockups, and packaging info.
Ship representative battery samples to the lab (typically 3–10 pcs), along with packaging material if applicable (for drop/fire tests).
The lab will test for electrical safety, thermal behavior, transportation safety, labeling compliance, and EMC (if required).
Once tests pass, you will receive the official report and/or certificate. CE requires a DoC; UL grants a UL file number; UN38.3 issues a test summary.
| Certification | Lead Time | Cost Estimate (USD) | Notes |
|---|---|---|---|
| CE (with IEC 62133) | 3–4 weeks | $2,000–$4,000 | EU-focused; includes lab + DoC support |
| UL2271 / UL2580 | 6–12 weeks | $8,000–$20,000 | US safety standard; longer process |
| UN38.3 | 7–14 days | $800–$2,000 | Required for air freight, any country |
Each lithium battery certification serves a different purpose—understanding their roles helps you stay compliant and market-ready.
Below is a detailed breakdown of the most important battery certifications, what they prove, and where they apply:
Purpose:
Confirms the battery meets essential health, safety, and environmental protection standards in the European Economic Area (EEA).
What It Covers:
Electrical safety
Thermal stability
Overcharge, short-circuit, vibration tests
Battery management system (BMS) protection validation
Applied Test Standard: EN/IEC 62133-2 for Li-ion batteries.
Required for:
Consumer electronics, eBikes, energy storage systems in the EU market.
Purpose:
Ensures battery safety and fire protection in the United States, commonly requested in large B2B and industrial contracts.
What It Covers:
Fire hazard testing
Battery abuse simulations
Dielectric resistance
Insulation and leakage evaluation
Typical UL Standards:
UL2271 for light electric vehicle batteries (e.g., eBikes, scooters)
UL2580 for EV/high voltage applications
UL2054 for household battery packs
Required for:
North American EV markets, retail chains, and brand certifications.
Purpose:
Mandatory for shipping lithium batteries via air (IATA regulations).
What It Covers:
Altitude simulation
Thermal tests
Vibration and shock
Overcharge and forced discharge
External short-circuit
Required for:
All air shipments globally. Customs will reject shipments without it.
Purpose:
Describes the chemical composition and handling safety for battery components.
What It Includes:
Hazard identification
Storage conditions
First aid measures
Toxicology and reactivity info
Required for:
Hazmat declarations in shipping, safety documentation for large buyers.
Purpose:
Proves that the battery does not contain restricted heavy metals or banned substances.
Limits substances like:
Lead (Pb)
Mercury (Hg)
Cadmium (Cd)
Hexavalent Chromium (Cr6+)
Required for:
Selling in Europe, and increasingly adopted in global retail markets.
Displaying certification labels correctly helps you avoid customs issues, build buyer trust, and pass inspections. Here’s how to apply them on your lithium battery products and associated documents:
What to Include on the Physical Label:
Certification marks (e.g., CE, UL logo)
Battery specifications (voltage, capacity, watt-hours)
Manufacturer info (name, contact, country of origin)
Model number & serial number
Warning signs (like “Do not short-circuit” or “Do not disassemble”)
Recycling & RoHS symbols
Label Placement:
For plastic shell packs: laser marking or durable sticker on the top/side
For shrink-wrapped soft packs: waterproof label affixed securely
Tip: Labels must be durable, legible, and resistant to wear and solvent exposure per CE/UL requirements.
A. Declaration of Conformity (DoC):
This document states that your battery product complies with applicable directives (e.g., CE, RoHS).
Must Include:
Manufacturer’s name and address
Product description
Applicable standards (EN62133, RoHS, etc.)
Name and signature of authorized person
Issue date
B. UL Test Report & CB Certificate Copies:
Required during customs checks, B2B onboarding, or product audits.
C. UN38.3 Report:
Always attach a full test report + transport certificate when shipping by air.
3. When to Use Certification in Product Listings or Catalogs
Good Practice:
Show CE/UL/MSDS/UN38.3 icons with hover tooltips
Add clickable “Download Certificate” links in product pages
Include a PDF bundle in your sales kit or Alibaba listing
Avoid:
Using fake or expired certificates
Showing CE mark without EN standard
Placing RoHS logo without documentation
Choosing the right lithium battery is critical for performance, safety, and longevity. Here’s a 6-step method to help you make an informed decision:
Start with the end use.
The first step is understanding what your battery will power. Each application has its own demands:
eBikes / Scooters: Require lightweight, high-current packs
Energy Storage Systems: Need long cycle life, stability
UPS / Backup Power: Prioritize high reliability
Power Tools / Robots: Demand high discharge rates
Medical / Telecom / Drone: Require certified, compact packs
Match your system’s specs.
Ask these questions:
What voltage does your motor or device require? (12V / 24V / 48V / 72V…)
How long should it run per charge? (Ah or Wh determines energy)
What is the peak and continuous power draw?
Higher capacity = longer runtime, but also more weight and cost.
Balance safety, cost, and performance.
| Chemistry | Key Advantage | Typical Usage |
|---|---|---|
| LiFePO₄ | Safe, long cycle life | Energy storage, telecom |
| NCM/NCA | High energy density | EVs, eBikes, power tools |
| LCO | Compact, short cycle | Consumer electronics |
Each chemistry affects performance, safety, temperature range, and cost.
Does the battery fit your device?
Common shapes:
Triangle Pack: For eBike frame integration
Rear Rack / Down Tube: For cargo or city eBikes
Wall-Mount / Rack-Mount: For ESS or telecom
Compact / Cylindrical / Pouch Cells: For drones, robots, tools
Custom casing and connectors may be needed for tight spaces.
Smart battery = safe battery.
The BMS (Battery Management System) controls:
Overcharge / over-discharge protection
Current limits (C-rating)
Thermal shutdown
Data monitoring: SOC, SOH, cycle count
Protocols: CANBus, RS485, Bluetooth
Choose based on your system’s communication and safety needs.
Don’t get blocked at customs.
Key certifications:
UN38.3 – Mandatory for air/sea transport
CE – Required for EU
UL – Required for US
MSDS / IEC62133 / RoHS – Safety & environmental
Suppliers should provide test reports, DoC, and labeled packaging.
Lithium batteries power everything from eBikes to energy storage systems, but choosing and using them wisely requires more than just knowing the voltage. This guide has walked you through the essentials—from battery cell types, chemistry, and internal structures, to smart BMS systems, testing methods, certifications, lifespan strategies, and safe handling. Whether you’re a buyer, engineer, or brand owner, understanding these fundamentals helps you select safer, more efficient, and fully compliant battery solutions tailored to your application. At the core, it’s not just about batteries—it’s about making smarter, longer-lasting energy decisions.
Need a custom lithium battery pack? Just send us your specs—we’ll help you choose the right voltage, case, and configuration for your application.
At JUNDA, we make customization easy. Follow these 3 simple steps to start today:
Send your battery requirements — voltage, capacity, casing type, or upload drawings/photos.
We’ll evaluate your specs and recommend the best configuration. A detailed quote will be sent within 24 hours.
After approval and deposit, we start production. Shipping and tracking will be arranged for fast, secure delivery.
