Custom Lithium Battery Packs – OEM Battery Assembly & Customization Guide
Published by A&S Power | Battery Technology
Introduction
A lithium battery pack is more than just a collection of cells – it‘s a complete power solution that combines cells, protection circuits, and connectors into a ready-to-use energy source. Whether you’re designing a medical device, a wearable, or an IoT sensor, the right battery pack can make the difference between a product that works and one that excels.
At A&S Power, we manufacture custom lithium battery packs for OEM buyers worldwide. This guide covers everything you need to know about lithium battery packs – from what they are to how they‘re customized and why choosing the right supplier matters.
For a complete overview of our custom battery capabilities, check out our full guide: Custom Lithium Polymer Battery – OEM/ODM Solutions for IoT, Wearables & Medical Devices.
What is a Lithium Battery Pack?
A lithium battery pack is an assembly of one or more lithium cells connected in series, parallel, or series-parallel configurations to achieve the desired voltage and capacity. The pack typically includes:
| Component | Function |
|---|---|
| Cells | Store and deliver electrical energy |
| PCM / BMS | Protection Circuit Module or Battery Management System – prevents overcharge, over-discharge, short circuit, and overcurrent |
| Connectors | Wires, terminals, or plugs to connect the pack to your device |
| Encapsulation | Heat-sealed pouches, plastic housings, or custom-molded enclosures |
| Labeling | OEM branding with your logo and product information |
Why Choose a Custom Lithium Battery Pack?
Off-the-shelf batteries rarely fit the unique requirements of OEM applications. A custom lithium battery pack offers:
| Benefit | Why It Matters |
|---|---|
| Custom dimensions | Fits your device‘s exact enclosure |
| Optimized capacity | Matches your target runtime |
| Custom voltage | 3.7V, 7.4V, 11.1V, or custom configurations |
| Built-in BMS | Overcharge, over-discharge, short-circuit protection |
| Custom connectors | JST, Molex, wire leads, or custom harnesses |
| OEM branding | Your logo and specifications on every pack |
| Global certifications | UL 1642 tested, CE, RoHS, UN38.3 |
Types of Lithium Battery Packs We Manufacture
| Pack Type | Cell Type | Voltage Options | Typical Applications |
|---|---|---|---|
| Single-cell packs | Li-Polymer pouch | 3.7V | Wearables, TWS earbuds, IoT sensors |
| Multi-cell packs | Li-Polymer pouch | 7.4V, 11.1V, 14.8V | Medical devices, portable speakers, drones |
| 18650 packs | Cylindrical Li-Ion | 3.6V – 14.8V | Power tools, flashlights, e-bikes |
| Custom-shaped packs | Li-Polymer pouch | 3.7V – 14.8V | Smart glasses, smart rings, curved devices |
| High-capacity packs | Li-Polymer / 18650 | 3.7V – 14.8V | Portable power stations, industrial equipment |
Customization Options for Lithium Battery Packs
As a custom lithium battery pack manufacturer, we offer full customization:
1. Cell Selection
We help you choose the right cell type (Li-Polymer or Li-Ion) and capacity for your application, balancing runtime, size, and cost.
2. Configuration
- Series (S): Increases voltage (e.g., 2S = 7.4V, 3S = 11.1V)
- Parallel (P): Increases capacity (e.g., 2P = double runtime)
- Series-Parallel: Both voltage and capacity customized
3. BMS Integration
- Overcharge, over-discharge, short-circuit protection
- Temperature monitoring with NTC thermistor
- Communication protocols: I²C, SMBus, CAN, HDQ
- Fuel gauge / State of Charge (SoC) reporting
4. Encapsulation
- Heat-sealed pouch wrapping – lightweight and compact
- Plastic housing – rigid protection
- Custom-molded enclosures – full mechanical integration
5. Connectors
- Wire leads with custom length and gauge
- JST, Molex, Anderson, XT60, or custom connectors
6. Labeling
- OEM branding with your logo
- Product specifications and safety markings
- Serial numbers and traceability codes
7. Certifications
- UL 1642 tested cells
- CE, RoHS, UN38.3 certified
- Full compliance documentation with every order
Applications for Custom Lithium Battery Packs
| Industry | Applications |
|---|---|
| Medical Devices | Patient monitors, diagnostic equipment, drug delivery systems |
| Wearable Devices | Smartwatches, fitness trackers, smart glasses, smart rings |
| IoT Sensors | Environmental monitors, asset trackers, smart home sensors |
| Consumer Electronics | TWS earbuds, Bluetooth speakers, portable chargers |
| Industrial Equipment | Handheld scanners, test equipment, portable tools |
| Portable Power | Power banks, portable power stations, emergency lights |
Why Choose A&S Power for Custom Lithium Battery Packs
✅ True Customization
We design and manufacture battery packs to your exact dimensions, capacity, voltage, and connector requirements – no off-the-shelf compromises.
✅ Engineering Support
Our team provides design reviews, thermal modeling, and BMS customization to ensure seamless integration into your product.
✅ Reliable Quality
100% final functional testing on every battery pack. Batch-level traceability for full accountability.
✅ Full Compliance
UL 1642 tested cells, CE, RoHS, and UN38.3 certification. Full documentation with every order.
✅ Direct Factory Pricing
Competitive pricing without middlemen or markups.
✅ Global Shipping
UN38.3 certified for safe air and sea transport worldwide.
Frequently Asked Questions
1. What is the difference between a battery cell and a battery pack?
A cell is a single electrochemical unit. A pack is an assembly of multiple cells with a BMS, connectors, and encapsulation, ready to use in your device.
2. Can you customize the shape of a lithium battery pack?
Yes. Li-Polymer packs can be shaped to fit any enclosure – rectangular, stepped, curved, or ultra-thin. 18650 packs are cylindrical but can be configured in various series-parallel arrangements.
3. What is the minimum order quantity (MOQ) for custom battery packs?
MOQ depends on the complexity of the pack. For standard configurations, MOQ starts at 1,000-3,000 units. For fully custom designs, we can work with lower volumes for prototyping.
4. How long does sample development take?
Typical sample lead time is 2-4 weeks. Mass production takes 4-6 weeks after sample approval.
5. What certifications do you provide?
UL 1642 tested cells, CE, RoHS, UN38.3, and IEC62133. Full documentation with every order.
6. Do you ship globally?
Yes. We ship to North America, Europe, Asia, Australia, and beyond with full UN38.3 certification.
Custom Lithium Battery Packs from A&S Power
At A&S Power, we manufacture custom lithium battery packs for OEM buyers across multiple industries. From medical devices and wearables to IoT sensors and portable electronics, we deliver tailored solutions with safety and performance in mind.
- ✅ Custom dimensions and capacities
- ✅ Li-Polymer and Li-Ion cell options
- ✅ UL 1642 tested cells, CE, RoHS, UN38.3 certified
- ✅ OEM labeling and packaging
- ✅ Engineering support from concept to production