You hear the term "battery pack" used for everything from cars to drones. This makes you assume that "battery pack" is just another name for a lithium battery.
Not always, but most modern, high-performance battery packs are lithium-based. A "battery pack" is a complete system, while "lithium" describes the specific battery chemistry inside that system. Today, lithium is the dominant chemistry for these packs.
As a manufacturer, we build battery packs, and the core of our work is integrating individual battery cells into a safe, reliable system. Think of it this way: a "battery pack" is the house, and the "battery cells" are the bricks. Those bricks can be made of different materials, but in modern construction, lithium is the high-performance material of choice.
What's the Difference Between a "Cell" and a "Pack"?
The terms "battery cell" and "battery pack" are often used interchangeably. This creates confusion, making it hard to understand the true structure and complexity of the power source you're using.
A cell is the single, fundamental electrochemical unit. A battery pack is a system built by combining multiple cells with a management system, housing, and safety features. The pack is the complete, usable product.
Understanding this distinction is key to understanding battery technology. One is a component, the other is a finished system.
The Building Blocks:
- Battery Cell: This is the smallest individual unit that stores energy (e.g., a single 18650 cell or a single LiPo pouch cell).
- Battery Pack: This is a system that includes:
- Multiple Cells: Connected in series (to increase voltage) or parallel (to increase capacity).
- Battery Management System (BMS): A crucial electronic board that protects the cells from over-charging, over-discharging, and short circuits. It also balances the voltage of each cell.
- Housing & Structure: A case that protects the cells from physical damage.
- Connectors & Wiring: To deliver power to the device and receive a charge.
A cell on its own is often unsafe and impractical to use. The battery pack turns those raw cells into a smart, safe, and robust power source.
What Kinds of Batteries Are Used in Packs?
You assume all battery packs must use the latest technology. This makes you wonder why old technologies still exist and if lithium is always the best choice.
While lithium-ion and lithium-polymer are the most common choices today, battery packs can be made from various chemistries. The choice depends on the application's requirements for cost, weight, and power.
Lithium isn't the only option, and it's not always the best one for every single job. Different "bricks" are used to build different types of "houses."
Common Battery Pack Chemistries:
| Chemistry | Main Use Cases | Pros | Cons |
|---|---|---|---|
| Lithium-ion/Polymer | EVs, Drones, Laptops, Phones | High energy density, lightweight | Higher cost, needs complex BMS |
| Lead-Acid | Car starters, UPS, E-bikes | Very low cost, high surge current | Extremely heavy, low energy density |
| Nickel-Metal Hydride (NiMH) | Hybrid cars (older models), power tools | Safer than Li-ion, good lifespan | Heavier than Li-ion, has memory effect |
So, while the battery pack in your drone is definitely lithium, the one in your gas-powered car (that starts the engine) is a lead-acid battery pack.
Why Do We Usually Mean "Lithium" When We Say "Battery Pack"?
In conversations about new tech, from EVs to grid storage, "battery pack" is almost always used to mean a lithium battery pack. This makes it seem like no other technology matters.
This is because lithium technology has become so dominant in high-growth, high-performance sectors that it's now the default assumption. The massive success of EVs, smartphones, and drones has made "lithium battery pack" the standard.
The language we use follows the technology we see every day. Twenty years ago, "rechargeable battery" might have made you think of NiMH. Today, it makes you think of lithium. This shift happened because:
- Electric Vehicles: The entire EV revolution is built on massive lithium-ion battery packs.
- Consumer Electronics: Every smartphone, laptop, and tablet uses a custom-shaped lithium battery pack.
- Energy Storage: Large-scale grid storage and home battery systems like the Tesla Powerwall are all based on lithium.
Because lithium is the engine of modern technological progress, the terms "battery pack" and "lithium battery pack" have become almost synonymous in popular and professional contexts.
Conclusion
A "battery pack" is not always lithium, but in most modern applications, it is. The pack is a complete system, and lithium is the high-performance chemistry used to build it.