Anyone building battery packs with 18650 cells eventually wonders what size nickel alloy strips to use. Getting the size right keeps the connection strong and safe—pretty essential for both performance and peace of mind.
Most builders stick to nickel strips that are 0.15mm to 0.2mm thick and 6mm to 8mm wide for 18650 cells. These sizes are popular since they handle the current from typical 18650 batteries without getting too hot or wasting energy.
Whether it’s for e-bikes, powerwalls, or some other DIY project, picking the correct strip size always matters. If you want battery packs that last and work well, understanding strip sizing is a must, and you can check more information on nickel alloy solutions.
Nickel Alloy Strip Sizes for 18650 Applications
Getting the nickel alloy strip size right is key for battery safety and performance. Width and thickness really depend on your cell count, assembly type, and the current you expect to pull.
Standard Widths and Thicknesses
Nickel alloy strips for 18650 batteries show up in a handful of standard sizes. Width is usually somewhere between 6 mm and 10 mm for single-row cell connections.
Thickness usually falls in the 0.10 mm to 0.20 mm range, though most folks use 0.15 mm or 0.20 mm.
Here’s a quick table of common strip sizes:
| Width (mm) | Thickness (mm) |
|---|---|
| 6 | 0.10 |
| 7 | 0.15 |
| 8 | 0.20 |
| 10 | 0.15 |
If you’re working with packs that need to handle higher current or have parallel cell groups, you might need wider or thicker strips.
Recommended Dimensions for Spot Welding
For spot welding 18650 packs, strip thickness makes a big difference for weld strength and current handling. 0.15 mm thick strips are a go-to for DIY and smaller packs—strong enough, but still easy to weld.
Width depends on your cell layout. Single cell connections usually get 6 mm to 8 mm wide strips. With bigger packs, 10 mm is sometimes better.
Your spot welder needs to punch through the nickel strip without hurting the cell. If the strip’s too thick, the weld might be weak; too thin, and the strip could burn or just not handle enough current. Thicker strips like 0.20 mm need a beefier welder and are used for higher currents.
Influence of Current Output on Strip Size
Current output is a huge factor in picking strip size. As the output current goes up, you need both more width and thickness to handle the load without overheating.
For most DIY e-bike or powerwall packs, 0.15 mm thick strips can take about 7–8 amps per string. If you’re pushing 10 amps or more through each strip, people usually go for 0.20 mm thickness or double up strips in parallel.
In high-current designs, using a wider or thicker nickel strip helps cut resistance and heat. It’s honestly not worth risking failures or unsafe connections—match your strip size to your expected current.
Choosing the Right Nickel Alloy Strip
Picking the right nickel alloy strip is crucial for safe connections and solid performance in 18650 pack assembly. Size, fit, and the purity of the material all play a big role in how your pack ends up working.
Compatibility With 18650 Battery Holders
18650 cells need strips that actually fit the width of their terminals and holders. The usual suspects for strip widths: 6mm, 8mm, and 10mm. That pretty much covers single and parallel spot welding jobs.
Thickness matters:
- 0.1mm – for low-current packs (under 10A per cell)
- 0.15mm – for moderate current draw (10-15A per cell)
- 0.2mm – for higher current (15-20A per cell)
The size you pick has to match the spacing in the holder, or you risk short circuits. Strips that are too wide or too thick can cause poor connections or just not fit. It’s worth taking the time to measure your holder and cells before buying strips—really saves headaches later.
Considerations for Battery Pack Design
The way you design your pack decides how many cells you use, how they’re arranged, and how much current each strip will handle. For packs with bigger current needs or more cells, you need both thicker and wider strips to carry the load safely.
When planning a pack:
- Pick a strip that can handle the highest current path in your design
- For long series strings, thicker strips help reduce voltage drop
- For parallel groups, make sure strips connect all cells evenly
Too thin, and the strip might overheat or cause voltage loss. Too thick, and spot welding gets tricky—and you could damage your cells. It’s always smart to check your design with a current chart for nickel strips, or at least run some numbers based on your total expected current.
Impact of Strip Material and Purity
Pure nickel is hands-down the go-to for 18650 battery strips. It’s got low resistance, and the corrosion resistance is hard to beat.
Plenty of strips out there are labeled as nickel, but they’re really just nickel-plated steel. That stuff? Higher resistance, wears out faster—kind of a letdown over time.
Spotting the real deal takes a bit of attention. Labels like 99.96% pure nickel are a good sign.
If you’re unsure, try a magnet test. Pure nickel’s just barely magnetic, but steel will stick right to it.
Material choice affects:
- Efficiency (lower resistance means less heat)
- Safety (real nickel doesn’t rust as easily as steel)
- Longevity (pure nickel strips hold up better in tough conditions)
It’s worth buying from suppliers you trust. Always double-check specs—having actual pure nickel strips makes a real difference for performance and safety in your 18650 pack.