In the electronics and energy storage sectors, 18650 batteries serve as a cornerstone. Their versatility and wide range of applications make them highly sought-after components across many industries. If you want to purchase 18650 batteries in bulk for your business, this article will walk you through the key points—how to find reliable suppliers, understand battery specifications, and get the best deals.

1. Understanding 18650 Batteries

Capacity Range

18650 batteries typically offer capacities ranging from 1800mAh to 3500mAh. The capacity determines how much energy the battery can store. For applications that demand long-lasting power—such as high-end flashlights or portable medical devices—batteries with a capacity of 3400mAh to 3500mAh are often the preferred choice. For devices with lower power requirements, a capacity of 1800mAh to 2000mAh may be sufficient and more cost-effective.

Cycle Life

Cycle life is another key factor. High-quality 18650 batteries can withstand hundreds or even thousands of charge-discharge cycles. For example, some top-tier lithium-ion 18650 batteries retain a significant portion of their original capacity even after more than 500 cycles. This makes them essential for products requiring long-term, repeated use—like power tools or off-grid energy storage systems.

2. Where to Find Reliable 18650 Battery Manufacturers and Factories

Apsen Technology stands out as a dependable channel for bulk 18650 battery sourcing. With years of experience in the battery manufacturing industry, Apsen Technology offers a wide selection of 18650 batteries in various capacities and specifications to meet diverse B2B needs. Whether you’re looking for standard 18650 cells for consumer electronics or customized solutions for industrial applications, Apsen Technology can be your ideal partner.

You can directly contact Apsen Technology to discuss your bulk purchase needs, including order quantity, preferred capacity, and any custom requirements. They can provide detailed product information and competitive pricing.

3. 18650 Battery Wholesale Pricing

Two main factors affect wholesale pricing for 18650 batteries: order quantity and battery capacity.

Quantity-Based Pricing
Generally, the more you order, the lower the unit price. Suppliers often use a tiered pricing structure. For example, small batch orders of 100 to 500 units tend to have a higher unit cost, while prices drop significantly for orders of 1000 units or more. Large-scale orders help suppliers reduce unit production, packaging, and shipping costs—and they’re willing to pass those savings on to buyers.

Capacity-Based Pricing

Higher-capacity batteries usually come at a higher price. For instance, a 3500mAh 18650 battery will cost more than an 1800mAh one. That’s because achieving higher energy storage requires better materials and more advanced technology. When estimating your B2B procurement costs, consider the relationship between capacity and pricing, and strike a balance between power requirements and cost-efficiency.

4. Customization Options

Many manufacturers—including Apsen Technology—offer customization services for 18650 batteries, which is especially valuable for businesses with specific product needs.

Capacity and Discharge Rate Customization

If your application demands non-standard capacities or specific discharge rates, manufacturers can customize the battery cells accordingly. For example, if you need a 2200mAh battery or a higher discharge rate to power high-performance equipment, they can tailor the product through technical adjustments.

Packaging and Label Customization

Manufacturers also offer custom packaging and labeling services. You can request packaging that fits seamlessly into your product assembly process. In addition, they can apply custom labels featuring your company logo, product specs, or branding—helping with both brand promotion and product identification.

Final Thoughts

When purchasing 18650 batteries in bulk for your B2B operations, it’s essential to understand the product specifications, find a trusted manufacturer like Apsen Technology, and recognize the factors that influence pricing. With careful planning and supplier communication, you can secure a stable supply of high-quality 18650 batteries at competitive prices.

The process of assembling lithium battery cells into a complete battery pack is called battery PACK. It involves integrating key parts such as the cells themselves, a protection board, nickel strips, and labeling materials. Through a series of processing and assembly steps, these components are combined into a fully functional battery pack.

Let’s go step by step and see how a lithium battery pack is designed and assembled.

What is a Lithium Battery Pack?

A lithium battery pack is essentially a circuit system made up of multiple lithium cells that work together to store and deliver energy.

Each pack can contain several cells, and each cell comes with its own voltage and capacity. By connecting cells in series or parallel, the pack can be configured to deliver either higher voltage or greater capacity. A charging system is typically built into the pack to supply energy to devices.

The size of a pack depends on the number and type of cells it contains. Common formats include 18650, 21700, 26650, 32700, and prismatic cells. The number of cells used directly influences the pack’s final size.

Step 1: Cell Sorting and Grouping

The first step is to sort and match the cells. Technicians group cells with similar characteristics to ensure consistency. Key parameters include:

• Internal resistance
• Voltage
• Rated capacity
• Charge/discharge efficiency
• Self-discharge rate

By grouping similar cells together, internal balance is improved, efficiency is higher, and the battery pack’s service life is extended.

Step 2: Cell Assembly and Fixture Alignment

The sorted cells are placed into structured fixtures and then spot welded together. Following the Standard Operating Procedure (SOP) is critical at this stage, especially ensuring correct polarity alignment (positive and negative terminals).

Proper alignment avoids short circuits and ensures electrical safety.

Step 3: Welding the Battery Pack to the PCM/BMS

Next, the cells are welded to a PCM (Protection Circuit Module) or a BMS (Battery Management System). This is essentially the “brain” of the pack.

It protects the battery from:

• Overcharging
• Over-discharging
• Short circuits

For low-voltage packs (<20 cells), a PCM with balancing features is often enough. For high-voltage packs (>20 cells), a BMS is essential, since it continuously monitors the cells to maintain safe operation.

Step 4: Insulating the Semi-Finished Pack

At this stage, insulation materials are applied and voltage sensing wires, output cables, and positive/negative terminals are secured.

⚠️ Care must be taken to avoid compressing or stacking wires, especially voltage sampling wires. Pressure on these can damage insulation and increase the risk of short circuits. Proper insulation ensures safe handling before the final assembly.

Step 5: Testing the Semi-Finished Pack

The semi-assembled battery is now tested for quality and performance. Typical tests include:

• Charge/discharge cycles
• Internal resistance checks
• Capacity measurements
• Safety tests (overcharge, over-discharge, short-circuit, overcurrent)

Depending on the application, additional stress tests may also be performed—such as high/low-temperature testing, nail penetration, drop resistance, and salt spray corrosion.

During these tests, technicians closely monitor how the battery responds. For example:

• In overcharge tests, they verify if the BMS safely handles high voltage.
• In short-circuit tests, they check whether the system can manage sudden current surges.
• In overcurrent tests, they see how well the BMS manages strong pulse currents.

Only after passing all tests does the pack move on to packaging.

Step 6: Battery Pack Packaging

The packaging method depends on the pack design.

• For PVC-wrapped packs, a heat-shrinking machine is used.
• For metal case packs, external casing is assembled.

Throughout the process, the battery must be handled carefully to avoid impact or compression. Proper insulation of wires is also crucial to prevent shorts..

 

Step 7: Final Pack Testing

In the last stage, the completed pack is tested on a comprehensive battery tester. Parameters such as:

• Total voltage
• Internal resistance
• Charge/discharge performance

are verified. If necessary, additional protection tests (short-circuit, overcurrent) are also carried out to ensure full safety.

 

Final Thoughts

After these steps, the lithium battery pack is fully assembled and ready for use. While the process may sound complicated, following each step carefully ensures a pack that is both safe and reliable, tailored to its intended application.

Drone batteries come in different types, each with its own strengths and limitations depending on the drone’s purpose. Here’s a breakdown of the most common options and where they are typically used.

Lithium Batteries

Advantages: These batteries offer high energy density, are lightweight, charge quickly, last a long time, and don’t suffer from memory effect.
Disadvantages: They cost more than other options, require strict charging and discharging control, and can be damaged by overcharging or deep discharging.
Application Scenarios: A great choice for mid-to-high-end drones, especially models that focus on being lightweight and having long flight endurance.

Lithium Polymer Batteries (LiPo)

Advantages: LiPo batteries are essentially an improved version of standard lithium batteries. They have higher energy density, weigh less, self-discharge more slowly, charge quickly, and offer long service life—making them an excellent energy solution.
Disadvantages: They are relatively expensive and need special protection circuits to operate safely.
Application Scenarios: Commonly found in small to medium-sized drones. They are especially useful for drones that need to carry extra batteries or equipment to extend flight time or handle additional payload.

Nickel-Metal Hydride Batteries (NiMH)

Advantages: Affordable, long-lasting, and more environmentally friendly than some alternatives.
Disadvantages: They have lower voltage, heavier weight, smaller capacity, and a higher self-discharge rate compared to lithium-based batteries.
Application Scenarios: Mostly used in entry-level or budget drones, making them suitable for beginners or users who don’t want to invest heavily.

Sealed Lead-Acid Batteries (SLA)

Advantages: Known for being inexpensive and reliable.
Disadvantages: Bulky, heavy, and with low energy density, they are not ideal for long flights or high-power needs.
Application Scenarios: Sometimes used in larger drones or for specific purposes, such as agricultural spraying drones.

Why Do Drones Use LiPo Batteries?

LiPo batteries are built with polymer electrolytes, lithium-based electrodes, and separators. Compared with older liquid electrolyte lithium batteries, they provide higher energy density, improved safety, and longer lifespan.

This is why LiPo batteries have become the go-to option for drones. They help extend flight time and make drones more reliable for demanding uses like aerial photography, security monitoring, agriculture, and even search and rescue missions. Their enhanced safety profile also makes them more dependable in real-world applications.

Looking ahead, graphene batteries could eventually become a powerful alternative for drones. But since the technology is still developing, they remain a future possibility rather than a current solution.

What is a 1.5V Lithium Battery?

A 1.5V lithium battery is a rechargeable lithium-ion battery that maintains a constant voltage of 1.5V throughout its entire discharge cycle without any drop. Internally, it uses a 3.6V lithium-ion cell, and through built-in circuitry, it regulates the output voltage to achieve 1.5V. This design provides strong power capabilities, making it ideal for devices that demand high current and voltage.

1.5V lithium batteries also support fast charging. For example, a single AA battery with a capacity of 3300mWh can fully charge in about 2 hours, whereas traditional nickel-metal hydride (NiMH) batteries may take around 10 hours.

Types of 1.5V Batteries

1. No. 1 Battery (D-type)

• Voltage: 1.5V
• Current: 1A
• Dimensions: Diameter 32.2mm, Height 59mm
• Short-circuit current: 1.5–2A

2. No. 5 Battery (AA-type)

• Most commonly disposable alkaline batteries
• Voltage: 1.5V
• Capacity: 600–700 mAh (for alkaline)
• Rechargeable variants include NiMH, NiCd (phased out), and iron lithium batteries
• NiMH: up to 2700mAh at 1.2V
• Iron lithium: up to 3000mAh at 3.2V

3. No. 7 Battery (AAA-type)

• Dimensions: Height 43.6 ±0.5mm, Diameter 10.1 ±0.2mm
• Types: dry cells, lithium batteries, NiMH, NiCd
• Common alkaline AAA batteries (e.g., LR03)
• Voltage: 1.5V, Capacity: ~1300mAh

Note: No. 5 batteries generally exceed 1600mAh, while No. 7 batteries usually do not exceed 900mAh.

Can 1.5V and 1.2V Batteries Be Interchanged?

It depends on the device. Devices with higher voltage requirements may not operate efficiently with 1.2V batteries. The key difference is that 1.2V batteries are rechargeable, while 1.5V batteries can be either rechargeable or disposable, depending on the type.

Advantages of 1.5V Lithium-Ion Batteries

Modern devices require reliable, rechargeable power sources. Disposable batteries are becoming less popular as many devices rely on electricity, making rechargeable lithium-ion batteries more practical and cost-effective.

Compared to NiMH batteries:

• Capacity does not fluctuate with charge state
• After repeated charging cycles, 1.5V lithium-ion batteries maintain about 80% capacity after 500–1000 cycles
• Reduce long-term operational costs

Before lithium-ion batteries, disposable alkaline batteries powered 1.5V devices. Lithium-ion batteries quickly replaced them due to rechargeability, eliminating the need for repeated battery replacements.

Environmental benefits:

• Reduce spent battery waste
• Minimize toxic materials such as mercury, lead, cadmium, and nickel in the environment
• Recyclable and more sustainable than disposable alternatives

Applications of 1.5V Lithium-Ion Batteries

1.5V lithium-ion batteries are widely used in daily life, powering:

• Small electronic devices (AA/AAA lithium-ion batteries)
• Household appliances
• Vehicles
• Hybrid and renewable energy storage systems

As the world shifts toward green energy from fossil fuels, 1.5V lithium-ion batteries will play an increasingly critical role. They are rechargeable up to 500–1000 times, which is roughly equivalent to 1000 disposable batteries, making them both economical and environmentally friendly.

Advancements in 1.5V Lithium-Ion Batteries

Ongoing research is improving the performance of 1.5V lithium batteries through new chemistries and designs, including:

• Lithium-sulfur
• Lithium-air
• Sodium-ion batteries
• Solid-state lithium batteries
• Lithium-ion solar batteries for higher energy density, lighter weight, and longer lifespan

These advancements allow 1.5V lithium-ion batteries to integrate with solar photovoltaics and other renewable energy technologies, further supporting sustainable energy solutions.