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The Faiuot dual farad spot welder is a supercapacitor-based battery spot welder with a 1.8-inch LCD, 250 adjustable power levels and an automatic trigger mode, aimed at nickel strip from about 0.1 to 0.3 mm. It is worth considering if you build lithium packs regularly and want fine power control. Skip it if you only need an occasional weld or you want a plug-and-play tool with a detailed manual.
Faiuot dual farad spot welder: quick specs
| Item | Per the listing |
|---|---|
| Type | Capacitor (dual farad) battery spot welder |
| Nickel strip range | About 0.1 to 0.3 mm |
| Peak output | Up to 2100 A (seller figure) |
| Energy storage | 3000 F supercapacitors |
| Power levels | 250 steps in 0.1 increments |
| Display and modes | 1.8-inch LCD; automatic and manual trigger |
| Weight | About 2.5 kg |
What sets a capacitor spot welder apart
A supercapacitor welder charges its capacitors, then dumps that energy into the strip in a very short pulse. The short pulse melts a small spot without heating the whole cell, which is the reason spot welding is preferred over soldering for battery packs.
The 250 power levels are the main selling point. Finer steps help you find the lowest setting that makes a good weld, which lowers the risk of burning through thin strip or heating a cell terminal. The automatic mode starts the pulse when the pen contacts the strip, which can speed up repetitive work.
How to check it fits your pack-building needs
- Strip choice: pure nickel at 0.1 to 0.2 mm is the easy case. Nickel-plated steel strip needs more energy. For options, see the pure nickel strip review and the nickel-plated steel strip review.
- Cell type: suited to cylindrical cells like 18650 and 21700. A 21700 cell spacer keeps terminals aligned.
- Power source: confirm the input and charging requirements on the listing before you order.
- Workflow: if you weld hundreds of joints, the automatic trigger and fan cooling matter. Note that some buyers mention fan noise, so consider a quiet workspace.
- Documentation: expect a short manual. Look for setup videos or maker documentation for this model.
Pros and limitations
Pros
- Fine-grained power control for different strip thicknesses.
- Large supercapacitors to deliver strong pulses.
- Clear LCD for settings, and an automatic mode.
- Portable at roughly 2.5 kg.
Limitations
- Peak current and capacity figures are seller numbers, not independent test results.
- Limited to thin nickel strip; not suitable for copper or aluminum.
- Setup and settings have a learning curve, especially with a short manual.
- Supercapacitors store a lot of energy, so careless handling around the terminals is a risk.
Getting reliable welds
- Clean strip and cell terminals with isopropyl alcohol before welding.
- Start at a low power level on scrap strip and cells, then increase until the weld holds under a gentle peel test.
- Press the pen firmly and evenly; poor contact causes spatter and weak welds.
- Make two weld spots per tab where possible.
- Let the unit rest if it heats up, and keep the cooling vents clear of dust.
Safety
- Wear safety glasses. Molten metal can spit.
- Do not weld on damaged, swollen or deeply discharged cells.
- Keep pens and strip from bridging both terminals of a cell.
- Work on a non-flammable surface and keep a fire-safe container nearby.
- Use a proper battery management system, fuses and insulation in the finished pack.
- Do not open the welder when charged or modify the capacitors.
Alternatives and related guides
- Portable battery spot welder for a handheld battery-powered option.
- Harfington nickel strip for another strip supply.
- Jewelry pulse spark welder if your work is precious-metal repair.
Frequently Asked Questions
What does dual farad mean on a spot welder?
It refers to supercapacitors, a pair of high-capacity capacitors that store energy and release it in one short pulse. The listing mentions 3000F capacitors. This lets a small unit deliver a very high peak current without a heavy transformer, but the stated figures are the seller’s, not a certified rating.
How thick a nickel strip can the Faiuot weld?
Per the listing, it is meant for nickel strip about 0.1 to 0.3 mm thick. Pure nickel is easier to weld than nickel-plated steel, which needs more energy. Start with lower power levels and increase gradually until a test weld holds when you try to peel the strip.
Does it weld aluminum or copper?
Not reliably. The listing is aimed at nickel strip for battery packs, and copper and aluminum conduct heat and current so well that small capacitor welders usually cannot weld them. If you need to join those metals, check dedicated equipment rather than expecting this unit to do it.
What power source does the welder need?
Check the listing for the exact input and charging method before you order, because it can involve an adapter or a battery supply. Use only the supply the maker specifies. A weak or wrong supply can lower weld energy and may damage the unit or create a hazard.
Conclusion
The Faiuot is aimed at builders who want fine control over thin nickel welds. Check the power supply and strip compatibility, calibrate on scrap, and treat the capacitors and cells with respect.
