10440 Battery Guide: Size, Voltage, Capacity, Uses & More

By Ufine, Updated on April 18, 2025

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Part 1. What is the 10440 battery size?

The 10440 battery is named based on its dimensions: 10mm in diameter and 44mm in length. This naming convention is common in the lithium battery world. Its compact size is nearly identical to a standard AAA battery, but don’t be fooled—while it may look the same, it’s built for very different tasks.

Most 10440 batteries are lithium-ion cells, meaning they provide significantly more power than alkaline or NiMH AAA batteries. That extra energy makes them ideal for devices that demand high output in a compact space.

Part 2. 10440 battery types and how to choose

Not all 10440 batteries are created equal. In fact, there are a few important distinctions that can affect performance, safety, and compatibility. Let’s break them down.

Protected vs. Unprotected 10440 Batteries

Protected 10440 lithium batteries include a built-in circuit board that prevents overcharging, over-discharging, and short-circuiting. These are ideal for beginners or anyone using them in sensitive or expensive devices.
Unprotected 10440 batteries, on the other hand, lack this safety layer. They can be slightly smaller and may fit in tighter compartments, but they also carry more risk. They should only be used if your device already includes protection circuitry.

Flat-Top vs. Button-Top

Flat-top batteries have a flat positive terminal and are often used in custom-built or tightly designed electronic devices.
Button-top versions include a raised positive end that makes contact easier in some flashlight or gadget designs.

18650 Battery Flat Top vs. Button Top: What is Different?

Branded vs. Generic

Brand matters. Low-quality cells can degrade quickly, swell, or even leak. Reliable manufacturers like Ufine Battery offer customizable, high-performance 10440 lithium batteries designed for specific needs, with quality assurance and certifications. Contact us now!

When choosing, always consider:

Your device’s voltage and size requirements
Capacity (mAh rating)
Protection needs
Whether button-top or flat-top is required

Choosing the right type ensures not only better performance but also longer battery life and safety.

Part 3. What is the voltage of the 10440 battery?

This is where the 10440 battery truly stands apart from common AAA batteries. While a typical AAA battery delivers 1.5 volts (alkaline) or 1.2 volts (NiMH rechargeable), the 10440 lithium battery provides a robust 3.7 volts.

That’s more than double the voltage.

This higher voltage enables stronger light in LED flashlights, faster spinning motors in fans or toys, and better performance in other high-drain devices.

However, it’s important to note: you should never use a 10440 battery in a device that expects 1.5V unless it explicitly supports lithium-ion cells. The increased voltage can permanently damage the electronics or cause overheating.

Always check your device’s specifications before swapping in a 10440 cell.

Part 4. What is the maximum capacity of the 10440 battery?

Despite its small size, the 10440 lithium battery packs an impressive punch when it comes to capacity.

Most high-quality models offer between 300mAh and 600mAh of energy. That’s lower than the capacity of AA or even some AAA batteries, but the tradeoff is a much higher energy-to-size ratio and voltage.

In premium or custom designs, like those made by Ufine Battery, the capacity can be tailored for your application. Some custom cells even push the limits to 650mAh, but space constraints mean the ceiling is relatively fixed.

When shopping, look at the mAh rating—it tells you how long the battery can run before needing a recharge.

Part 5. 10440 Lithium battery advantages

So, why go for a 10440 lithium battery over a traditional AAA?

Here are the standout benefits:

Rechargeability: You can charge it hundreds of times. That means less waste and lower long-term cost.
High Voltage Output: At 3.7V, it powers devices with more strength and efficiency.
Compact and Lightweight: It’s the same size as a AAA, but with more energy packed inside.
Stable Performance: Lithium-ion chemistry provides steady output and resists voltage drop.
Eco-Friendly: By reusing and recycling these batteries, you reduce harmful landfill waste.

For anyone using compact electronics, it’s a game-changer. You get the power of a larger battery in a body that fits the smallest devices.

Part 6. 10440 Battery vs AAA battery

Let’s compare the two side by side:

Feature	10440 Battery	AAA Battery
Chemistry	Lithium-ion	Alkaline or NiMH
Voltage	3.7V	1.5V or 1.2V
Rechargeable	Yes	Sometimes (NiMH only)
Capacity	300–600mAh	1000–1200mAh
Application	High-drain devices	Everyday low-drain use
Cost per unit	Higher initially	Lower initially
Long-term value	Higher (reusable)	Lower (disposable)

While AAA batteries are fine for clocks or TV remotes, 10440 batteries shine in gadgets that need power density and frequent use—like flashlights, laser pens, or small tech.

Part 7. Where is the 10440 battery used?

Thanks to their size and power, 10440 lithium batteries are widely used in:

EDC (Everyday Carry) flashlights
Laser pointers
Mini fans and portable devices
Wearable tech (fitness trackers, smartbands)
DIY electronics and Arduino projects
Tactical equipment
Medical monitoring tools

They’re a favorite among tech enthusiasts, outdoor lovers, and developers who need maximum power in minimal space.

Part 8. Is the 10440 battery rechargeable?

Yes, absolutely. The 10440 battery is rechargeable—and that’s one of its greatest strengths.

But to charge it safely and efficiently, you need the right charger.

What to Look For in a Charger:

Voltage Support: It must support 3.7V lithium-ion cells
Adjustable Current: Charging too fast can overheat or degrade the battery
Smart Features: Overcharge protection, auto shutoff, and cell detection are a must
Compatibility: Make sure the battery fits physically in the charger slots

Some brands offer dedicated 10440 lithium battery chargers, while others support multiple sizes. Always avoid cheap, unregulated chargers. They can shorten battery life—or worse—cause safety hazards.

Part 9. What can replace the 10440 battery?

Need a substitute for the 10440 battery?

Here are some options—but proceed with caution:

AAA batteries (alkaline or NiMH): Only if your device supports lower voltage. Otherwise, performance will suffer.
10440 LiFePO4 cells: These offer 3.2V, slightly lower than lithium-ion, but they are more stable and safer.
Custom lithium packs: For advanced users only. May require rewiring or voltage balancing.

In most cases, the safest option is to replace a 10440 battery with another 10440 lithium battery of equal size and voltage.