How to Spot Weld 18650 Batteries? Learn Method, Types, and Steps

Spot welding 18650 batteries means joining cells using heat and pressure. This method creates a quick, strong connection without damaging the cell.

A common inquiry I receive is how to spot weld 18650 batteries. It’s crucial to know this technique because it affects the battery’s performance and longevity. When I first learned, I made mistakes that impacted battery efficiency, teaching me the importance of precision and technique.

In this guide on how to spot weld 18650 batteries, we’ll cover what spot welding is, types of spot-welded batteries, the steps you need to take for successful welding, factors that affect the process, and answers to frequently asked questions. You’ll find valuable insights on related topics like how to spot weld battery tabs and how to remove spot welds from batteries too.

How to Spot Weld 18650 Batteries?

Spot welding 18650 batteries means creating electrical connections on the battery tabs. To spot weld 18650 batteries, use a spot welder with settings around 8–15 milliseconds (Ms), taking care as it’s tricky. This method suits battery packs and repairs.

What is Spot Welding 18650 Batteries?

Spot welding 18650 batteries is a method of joining battery cells using a precise welding technique. In this process, an electric current flows through the electrodes to melt and fuse a nickel strip to the battery terminals. The melting happens within milliseconds, creating a strong bond without overheating the cells. Spot welding achieves a bond strength of about 850-1200 MPa, ensuring durability during use.

So, how do you spot weld 18650 batteries? It starts with selecting the right battery spot welder, such as a mini spot welder that’s perfect for DIY projects. From my experience, choosing the right voltage setting is crucial; I usually use around 4 to 6 volts to prevent damage to the cells.

There was a time when I used it to build my custom battery packs. When I first tried to spot weld battery tabs, I quickly learned that a secure connection is key to safety and performance. With the proper technique, I avoided the headaches of removing spot welds from battery tabs, which can be a real challenge if done incorrectly.

Types Of Spot-welded 18650 Batteries

• Nickel Strip Batteries

  These batteries have nickel strips attached for electrical connection. To weld, place the strips on the battery terminals and press the welder’s trigger. Use a battery spot welder to make quick, strong connections lasting about 0.2-0.5 seconds. If spatter occurs, there are effective methods to .

• Flat Top Batteries

  Flat top batteries feature an even surface at both ends, aiding uniform welding. To spot weld, align the battery with the nickel strips, ensuring precise contact. Apply the welder with settings around 25-40 amps for optimal weld strength. It is also crucial to consider potential hazards such as which can impact your safety during the process.

• Button Top Batteries

  Button top batteries have a raised button structure that affects how you connect them. To spot weld, lay the strip down and adjust the welder to touch the center. Focus on a quick pulse lasting under 0.4 seconds for a solid bond without overheating the cells. Using the correct protective gear is imperative since can lead to serious hazards.

• Protected Batteries

  Protected batteries have built-in circuits to prevent overcharging, adding complexity. To weld, secure the nickel strip away from the protection circuit. Switch your welder to a lower pulse, typically under 20 amps, to avoid damage.

• Unprotected Batteries

  Unprotected batteries lack additional circuitry, making them simpler to weld. To spot weld, connect the strip directly to the terminal. Use a setting of 30-50 amps for a reliable weld.

We covered the different types of spot-welded 18650 batteries. Next, we will cover the steps for spot welding them.

Tools and Materials for Spot Welding 18650 Batteries

To successfully spot weld 18650 batteries, you need specific tools and materials. Here’s what you’ll need:

Essential Tools

• Spot Welder: A quality spot welder is key. Look for models with at least 1000A output.
• Welding Electrodes: Copper electrode tips work best. They conduct heat well and last longer.
• Battery Holders: These keep your batteries in place while you weld.

Necessary Materials

• Nickel Strips: Use nickel strips to connect the batteries. Thicker strips (0.15mm to 0.2mm) are more reliable.
• 18650 Batteries: Ensure they’re compatible. Most lithium-ion batteries will do.

Having the right tools and materials makes your job easier and improves quality. Are you ready to get started?

Steps for Spot Welding 18650 Batteries

Here are the steps for successfully spot welding 18650 batteries. Follow each step carefully for the best results!

1. Prepare Battery Cells

   Clean the battery terminals with a cloth or sandpaper to remove dirt or corrosion. This ensures a solid connection. Use a clean nickel strip about 0.15 mm (0.006 In) thick and at least 50 mm (2 in) wide for making tabs, which makes welding easier.

   Next, align the cells with the positive and negative terminals side by side. Ensure a snug fit—the tighter the fit, the better your welds. A good fit reduces heat loss during welding.

2. Set Up Welding Equipment

   Plug in your battery spot welder and place it on a stable surface. Check connections carefully to avoid electrical issues. Use flat welding tips for flat nickel strips. Adjust the welding arm for easy access to all necessary points.

3. Adjust Welding Settings

   Set your welder to a low pulse duration of about 10-20 milliseconds (Ms)—just enough to create a solid bond without overheating the cells. Higher settings can melt the tab and damage the battery. Start with a low energy setting (Around 10-20 J) and increase it later if needed. Monitor the spot weld quality during adjustments. To achieve efficient results with modern equipment, consider exploring the capabilities of .

4. Perform Spot Welding

   Place the welding tip on the nickel strip directly above the battery terminal, ensuring contact. Activate the welder by squeezing the trigger with firm, even pressure, and hold for about 10-20 milliseconds (Ms). After welding, don’t move the tip right away. Allow the weld to cool for improved strength. Pull the tip away, then check for a clean, shiny weld. If the weld looks dark or uneven, adjust the settings!

5. Inspect Welded Connections

   Examine each weld for uniformity. Good welds should appear shiny and solid. If you find uneven welds, consider re-welding. It’s crucial to check for proper electrical connectivity too. Use a multimeter to ensure there are no short circuits or disconnections.

So far, we covered the steps involved in spot welding 18650 batteries. Next, let’s look at the factors that influence this process.

Factors Influencing Spot Welding Of 18650 Batteries

What factors impact effective spot welding of 18650 batteries?

• Material Thickness

  The material thickness is crucial in spot welding. Typically, 18650 battery tabs are about 0.15 mm (0.006 In) thick. Thicker materials require higher current for effective fusion.

• Welding Current

  Welding current directly affects the heat generated during the process. A typical range is 300 A to 600 A. If the current’s too low, you’ll fail to achieve a solid joint; too high can melt the material.

• Electrode Pressure

  Electrode pressure is vital for good contact. I usually apply about 5 to 10 daN (Decanewtons) of force. Excess pressure can deform the battery tab, while insufficient pressure won’t create a proper weld.

• Welding Time

  The duration of the current application is important. A typical welding time is around 10 to 20 milliseconds. Longer durations create larger heat-affected zones, which can affect battery performance. Understanding different welding processes is crucial for optimizing these parameters.

• Cooling Time

  Cooling time is as essential as welding time. After the weld, letting the joint cool for about 1 to 2 seconds helps solidify the connection. Insufficient cooling can result in weak or incomplete welds.

We covered the factors affecting spot welding of 18650 batteries. Next, we will cover frequently asked questions (FAQs).

Frequently Asked Questions (FAQs)

Now let us look at some common questions I typically get asked about spot welding batteries.

How to Spot Weld Batteries Properly?

Yes, to spot weld batteries properly, you need the right equipment and settings. Using a calibrated battery spot welder ensures consistent heat and pressure, crucial for strong unions. Poor welding can lead to overheating, with serious risks like fire or battery failure.

How to Remove Spot Welds From Battery Tabs?

To remove spot welds from battery tabs, use a specialized spot weld removal tool. Proper tools minimize damage, preventing further disruptions in battery performance. Improper removal can harm the battery’s integrity, leading to costly replacements. It’s also crucial to be aware of the potential health risks associated with welding processes and take appropriate measures to .

Is It Better to Spot Weld or Solder Batteries?

Spot welding is generally better than soldering batteries for creating strong connections. This method uses heat and fusion, avoiding solder’s potential for weak joints, and resulting in lower resistance. Lower thermal impact also preserves battery health, maintaining its lifespan.

How to Spot Weld Battery Packs?

To spot weld battery packs, position the tabs accurately and select the right current settings. This ensures quality welds necessary for safe operation and performance. A faulty pack could lead to efficiency issues and costly replacements in electric vehicles or tools.

Do Battery Spot Welders Work?

Yes, battery spot welders work effectively for joining battery contacts. They provide the precise amount of heat at the weld point, creating solid connections that last. Using the right machine guarantees a reliable bond, essential for high-performance applications.

Conclusion

We’ve made it to the end, and I hope it was helpful. We covered essential topics like what spot welding is, different types of spot-welded 18650 batteries, and the steps to achieve a good weld. We also looked at factors that influence the welding process and answered some frequently asked questions.

Hopefully, I was able to impart some of my experience on how to spot weld 18650 batteries. Remember, using the right technique and equipment makes all the difference. Now you know the crucial steps and factors, plus safety considerations, to keep those lithium batteries secure when spot welding.

If you’re eager to enhance your understanding further, I encourage you to check out What is Welding for comprehensive insights into the welding world.

References

• International Institute of Welding (IIW): https://www.iiwelding.org