Seesii SE-001 Portable Battery Spot Welder: features, specs and uses

The Seesii SE-001 is a compact, battery-powered spot welder. It is built for joining nickel strip to battery cells, which is how DIY battery packs are usually assembled. It has its own rechargeable battery, an LCD and 80 adjustable power levels, and it comes with a welding pen and nickel strip.

What a spot welder does here

A spot welder passes a short, strong pulse of current through two touching pieces of metal. The resistance at the contact point heats it enough to fuse the pieces together. For battery packs, this joins thin nickel strip to the terminals of cells without the long heating that soldering would put into them. Seesii lists use on cylindrical cells such as 18650, and on NiMH and nickel-cadmium batteries.

80 power levels

Seesii says the welder has 80 adjustable levels: gears 1 to 8, with finer steps in between (it describes this as 1.1 to 5.4 to 8.0). A lower level suits thin strip, and a higher level suits thicker material. In general, it is wise to test on scrap of the same material and adjust upward, because too much energy can burn through the strip or overheat a cell.

LCD screen

A colour LCD shows the remaining battery, the delay time, the temperature and the gear level. Seesii presents this as a way to see the working state at a glance.

Built-in battery

The 7500mAh built-in battery charges in about 3 hours over a Type-C cable, according to Seesii, which says a full charge is enough for thousands of welds. The welder can also charge a phone. Because the unit runs from its own battery, no mains power is needed at the bench.

Welding pen and portability

The gold-plated welding pen has a 40 cm lead with high-temperature wire, which Seesii describes as having fine conductivity and torsional resistance. The body measures 7.1 x 3.5 x 1.2 inches (about 18 x 9 x 3 cm), so it is easy to carry and put away.

In the box

Seesii lists the nickel strip and a USB charging cable with the welder. Check the contents list for the full package.

Who it suits

It suits hobbyists building or repairing battery packs, such as for e-bikes, tools or power banks, and anyone who wants a small portable unit for occasional nickel-strip work.

What to check before you buy

• Material thickness: confirm that the nickel strip you plan to use is within the welder's range.
• Cell safety: battery work carries risks of heat and short circuits. Follow the manual, wear eye protection and use appropriate precautions.
• Practice first: try on scrap material.
• Charging: you need a Type-C charger.
• Technique: check how to hold the pen, since good results depend on firm contact.
• Upkeep: pen tips can wear and need cleaning.

The short version

• A portable spot welder for nickel strip on 18650, NiMH and nickel-cadmium cells.
• 80 adjustable power levels and an LCD showing battery, delay, temperature and gear.
• 7500mAh built-in battery that charges over Type-C in about 3 hours.
• Gold-plated pen with a 40 cm lead; nickel strip included.

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