Lithium Battery Sizes Guide: 18650, 21700, LiPo & Coin

Part 1. Fast lithium battery size lookup

Looking for lithium battery sizes? Here’s the fastest reference:

This quick lookup helps you identify the most common lithium battery types and sizes instantly.

Part 2. What do battery size codes mean?

Lithium battery codes are typically shorthand for physical dimensions in millimeters:

• 18650 → 18 mm diameter × 65 mm long
• 21700 → 21 mm × 70 mm
• 104050 (pouch) → 10 mm × 40 mm × 50 mm
• CR2032 (coin) → 20 mm × 3.2 mm

This kind of naming helps everyone — manufacturers, engineers, and hobbyists — know exactly what size a battery is just by looking at its code.

Part 3. Common cylindrical lithium battery sizes

Cylindrical lithium batteries are everywhere — from flashlights to electric bikes — partly because their sizes have become industry standards.

Here are typical sizes you’ll see:

Most cylindrical sizes follow a diameter + length format, so once you know the pattern, you can easily decode almost any battery code.

Part 4. Pouch (LiPo) battery sizes

LiPo (lithium polymer) batteries don’t use diameter/length codes like cylindrical cells. Instead, they are labeled by thickness × width × height because they’re often custom-shaped.

For example:

A “103450” pouch cell would be roughly 10 mm thick × 34 mm wide × 50 mm tall.

If you want to learn more about the detailed sizes of 3.7V lithium batteries, check out our complete guide: A Complete Guide to 3.7 Volt Battery Sizes

Why does this matter?

• Pouch cells are great for space-constrained designs like drones and smartphones
• They offer high energy density and flexible form factors
• But they also require protective housings because they can swell or deform

Part 5. Prismatic lithium battery dimensions

Prismatic cells look like little rectangular bricks. These aren’t as standardized as cylindrical ones, but they’re often used in larger battery systems, like energy storage or EV modules.

Typical characteristics include:

• Rectangular shape with metal casing
• Varying sizes depending on manufacturer and chemistry
• Excellent for stacked battery modules in industrial systems

You’ll see prismatic cells everywhere from solar storage to UPS backups.

Part 6. Button / coin lithium battery sizes

If you’re powering tiny electronics like wristwatches or key fobs, coin cells are likely your go‑to. These are super compact but still pack dependable energy.

Here are a few examples:

The CR series is one of the most widely used coin cell series.

Similarly, if you’re interested in the sizes of CR series coin cells, take a look at CR Battery Sizes: A Complete Guide

Part 7. What’s the largest lithium battery in practice?

When people talk about “the biggest lithium battery,” they’re usually referring to grid‑scale energy storage systems — not single cells.

For example:

• Australia’s Hornsdale Power Reserve was one of the world’s largest lithium-ion batteries at about 194 MWh after expansion.
• The Victorian Big Battery provides around 450 MWh of grid storage capacity.

These systems are assembled from many large-format cells and modules — but the point is, the largest real-world battery systems today are measured in megawatt‑hours, not millimeters.

Part 8. What’s the smallest?

On the other end, the smallest lithium batteries are usually coin cells like CR1220 or CR1620 — just a couple of millimeters thick.

Even the popular CR2032 — often used in watches and remotes — is only 20 mm across and 3.2 mm thick.

These tiny powerhouses keep low‑power devices running for months or years without replacement.

Part 9. How to choose the right lithium battery size

Here’s a quick checklist before you pick a battery:

• Space: How much room do you have in your design?
• Voltage: What voltage does your device need?
• Capacity: How long does it need to run before recharging?
• Current Demand: Does your device draw steady or burst currents?
• Form Factor: Cylindrical? Prismatic? Pouch? Coin?

Each form factor has trade‑offs — but understanding these basics helps you narrow choices fast.

Part 10. FAQs

Which lithium battery sizes are most common for general electronics?

Cells like 18650, 21700, and pouch (LiPo) formats are very common in consumer tech and power tools.

Do lithium battery sizes affect performance?

Absolutely — size influences capacity, discharge rates, and how well a battery manages heat.

Are all lithium battery sizes standardized?

Cylindrical and coin cells have widely followed standards, but pouch and prismatic cells often vary by manufacturer.

Can I use a bigger cell in place of a smaller one?

Only if the voltage, size, and device design allow it — always check dimensions and specs.

If you need an even faster tool‑style reference or want to tailor this to a specific device, I can help you build a custom lookup chart or a sidebar calculator next.