18650 Battery Flat Top VS. Button Top: What Is Different?

By Ufine, Updated on April 25, 2024

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In the world of rechargeable batteries, the 18650 battery types are incredibly popular, with flat top and button top designs being two of the most common variants. Choosing between flat top and button top 18650 batteries can be confusing. This guide explores the key differences, pros, cons, and how to select the best battery for your device, ensuring you make the right choice.

Part 1. What is an 18650 flat top battery and why choose it?

A flat-top 18650 battery is a cylindrical lithium-ion battery with a flat positive terminal. It lacks the protruding button found on the positive end of the battery. The flat top design allows for a more compact form factor, making it suitable for devices with tight battery compartments.

18650 Flat Top Battery Pros&Cons

Flat Top Batteries Pros:

Compact Size: The absence of a protruding button makes flat top 18650 batteries more compact, enabling them to fit into devices with limited space.
Versatility: Flat-top batteries are compatible with a wide range of devices that require 18650 batteries, including flashlights, vaporizers, and power tools.
Enhanced Safety: The flat design reduces the risk of accidental short-circuits when inserting or removing the battery from the device.

Flat Top Batteries Cons:

Limited Compatibility: Some devices, particularly those designed to accommodate button-top batteries, may need to be compatible with flat-top variants. The absence of a button can prevent proper electrical contact in such cases.
Lower Capacity: Due to their compact size, flat-top batteries may have slightly lower capacity than their button-top counterparts. This means they may provide somewhat less runtime in specific devices.

Part 2. What is an 18650 button top battery and why choose it?

As the name suggests, a button top 18650 battery features a protruding button on the positive end of the battery. Many often refer to this design as a raised or protruding positive terminal.

18650 Button Top Battery Pros&Cons

Button Top Batteries Pros:

Compatibility: Button-top batteries are suitable for devices specifically designed to accommodate this type of battery. They ensure proper electrical contact, particularly in devices with spring-loaded battery compartments.
Higher Capacity: Button-top batteries often have a higher capacity than flat-top variants. This means they can provide longer runtime in devices with high power consumption.

Button Top Batteries Cons:

Size Limitations: The protruding button design makes button-top batteries slightly more significant than their flat-top counterparts. This can be a limitation in devices with tight battery compartments.
Potential Short-Circuit Risk: The raised button increases the chances of accidental short-circuits if the battery comes into contact with conductive materials when not in use or during storage.

Part 3. Differences between flat top and button top 18650 batteries

The two main 18650 battery types—flat top and button top—offer distinct features that affect device compatibility and performance.

Dimensions:

Flat top 18650 batteries have a flat positive terminal, which means the positive terminal is flush with the top of the battery.
Button top 18650 batteries feature a protruding positive terminal resembling a small button on top of the battery.

Compatibility:

People commonly use flat-top batteries in devices with spring-loaded or sliding battery compartments that accommodate flat terminals.
Users prefer button-top batteries for devices with fixed or rigid battery compartments explicitly designed for button-top terminals.

Contact Surface:

The flat-top battery design of the positive terminal may provide a larger contact surface area in some devices, potentially improving connectivity.
The positive terminal’s button top battery protruding nature ensures direct contact with the battery contacts in devices with recessed or limited battery compartments.

Device Suitability:

Devices with flexible battery compartments and those designed for flat-top batteries are suitable for flat-top 18650 batteries.
Devices with fixed or specialized battery compartments, particularly those requiring button-top batteries, are compatible with button-top 18650 batteries.

Handling:

Flat-top batteries may be easier to handle and insert into devices with spacious or open battery compartments due to their flat profile.
Button top batteries are advantageous for devices with specific battery compartment designs, as the protruding terminal aids alignment and insertion.

Application:

Flat-top batteries are versatile and widely used in various electronic devices, including flashlights, laptops, and electric vehicles.
Users prefer button-top batteries for devices requiring a protruding positive terminal, such as flashlights and specific vaping devices.

Design:

The flat design of flat-top batteries may provide a sleek and uniform appearance when installed in compatible devices.
The button-shaped terminal of button-top batteries adds a distinctive feature to devices designed to accommodate them, enhancing aesthetics in some cases.

Aspect	Flat Top 18650 Battery	Button Top 18650 Battery
Dimensions	Flat positive terminal, flush with the top of the battery	Protruding positive terminal resembling a small button
Compatibility	Works with devices using flat terminals or spring-loaded compartments	Best for devices with fixed or specialized battery compartments
Capacity	May have slightly lower capacity due to compact size	Generally offers higher capacity for longer runtime
Risk of Short-Circuit	Lower risk due to flat design	Higher risk of short-circuit if improperly stored due to exposed button
Application	Versatile for various devices (flashlights, laptops, etc.)	Preferred for high-power devices like vaping devices

When deciding between a flat-top battery vs button-top, understanding their unique characteristics will help you choose the best option for your device.

Part 4. Considerations for choosing between the flat-top and button-top batteries

When buying 18650 batteries, consider factors like device compatibility, space constraints, and power requirements.

Device Compatibility

Determine whether your device requires a specific type of battery. Some devices may explicitly state the compatibility requirements or have physical limitations requiring flat-top or button-top batteries.

Space Constraints

Assess the available space within your device’s battery compartment. A flat-top battery may be a better fit if it has limited space. However, a button-top battery can provide higher capacity and longer runtime if space is not a concern.

Power Requirements

Consider the power demands of your device. A button-top battery with a higher capacity may be more suitable if it requires high power consumption. For devices with lower power demands, a flat-top battery should suffice.

Safety

Evaluate the safety implications of each design. Flat-top batteries reduce the risk of accidental short-circuits. In contrast, button-top batteries may be more prone to such incidents if not stored properly.

Conclusion

The choice between flat and button top 18650 batteries depends on device compatibility, space constraints, power demands, and safety considerations. Flat-top batteries offer versatility and compact size, while button-top batteries provide better compatibility with specific devices and higher capacity for sustained high-power output. To make an informed decision when buying 18650 batteries, weigh the pros and cons of each battery type carefully.

Part 5. Understanding power demands for different devices

When choosing between flat top and button top 18650 batteries, it’s important to consider the power requirements of your device. For high-power devices like electric vehicles or power tools, a button top battery with a higher capacity is often necessary to provide extended runtime. In contrast, devices with lower power demands, such as handheld flashlights, can benefit from the compact design of a flat top battery. Understanding your device’s power consumption is key to ensuring optimal performance.

Part 6. FAQs

Which is better for vaping: flat top or button top 18650 batteries?

Button top 18650 batteries are generally considered better for vaping due to their higher capacity and compatibility with high-power devices.
Can I use a flat top battery in a button top device?

No, flat top batteries are not suitable for devices that require a protruding button, as they won’t establish proper contact.
How do I know which 18650 battery is compatible with my device?

Check your device’s manual for battery compatibility or look for physical indicators such as spring-loaded compartments or fixed terminals.
Are button top 18650 batteries safer than flat top batteries?

Both types are safe when used correctly, but button top batteries may pose a short-circuit risk if not stored properly due to the exposed button.