Best Spot Welders in 2027

The AWithZ UK3 leads our ranking. It delivers 1650A of output and 13.8KW of maximum power, enough for consistent welds on cylindrical cells, phone batteries and button batteries, and it handles nickel strips up to 0.3 mm thick, tied for the thickest listed here.

It offers three ways to trigger a weld: an automatic mode that fires when the pen touches the strip, a manual mode with a button on the welding pen, and a foot pedal. That flexibility helps when you weld many cells in a row or need both hands to hold parts.

A large 10000mAh built-in battery charges over 5V USB Type-C and runs for long sessions, and a 6-gauge pure copper welding pen keeps resistance low for steady welds. It has 100 power levels, a display and thermal protection. For DIY battery builders, it is the best choice here. Practice on scrap strip first.

Second in our ranking, the Seesii SE-402 delivers 10KW of peak output and welds nickel-plated sheets under 0.3 mm and pure nickel sheets under 0.15 mm, according to Seesii, which covers most DIY battery pack work.

Its built-in 10000mAh battery supports more than 300 welds per full charge in Seesii's tests, so it can handle a full e-bike or power tool pack without being plugged in. Automatic and foot pedal modes are included.

A color screen shows real-time voltage and other parameters, and Seesii notes that weld quality depends on keeping the voltage level up. It has 25 power levels, fewer than the AWithZ. For hobbyists who want a portable, capable welder, it is good value. Start at a low power level and test on scrap nickel strip before welding cells, raising the power until the weld holds firmly without burning through. Keep the battery well charged, since weld quality drops as the voltage falls, and wear eye protection.

The AWithZ P30C ranks third. It is a capacitor welder with 21800W of maximum pulse power, the highest on this page, and 999 power levels for very fine adjustment.

Two built-in super capacitors store energy and release it in a pulse, and AWithZ says these capacitors have a long cycle life. It runs on 100 to 240V mains through a 15 amp adapter, so it is quick to start and does not depend on a charged battery.

Automatic and foot pedal modes are included, and AWithZ lists use on 18650, 14500 and 21700 cells and LiFePO4 batteries. Its maximum strip thickness is not listed in our data. For users who build many packs at a bench, it is the most powerful choice. Start at low settings and practice on scrap strip, since its high power can burn through thin nickel. Work on a non-flammable surface and keep cells from shorting. Raise the power a few steps at a time until the weld holds firmly.

Fourth in our ranking, the AWithZ UF20B is another mains-powered capacitor welder, with 10500W of maximum power and 99 power levels. It runs on 100 to 240V input through a 15 amp adapter.

Its 3-in-1 design offers automatic mode, manual mode and foot pedal mode, so you can work the way that suits the job. AWithZ lists the same wide range of cells as the P30C, including 18650, 14500, 21700 and LiFePO4 batteries.

It has less peak power than the P30C, but plenty for common nickel strip. Its maximum strip thickness is not listed in our data. For bench users who want three trigger modes in a mains welder, it is a sound pick. Practice on scrap nickel first, raising the power until welds hold without burning through. Use the foot pedal when you need both hands to steady the strip and cell, and keep cells on a non-flammable surface. Wear eye protection, since sparks are common at higher settings.

The Awgem SK1P3 completes our top five. It is a battery-powered welder with 11500W of peak power and dual-pulse technology, welding up to 0.25 mm nickel-plated strip and 0.3 mm steel, according to Awgem.

A rotary knob gives precise control over 100 power levels, and it switches between automatic and foot pedal modes. The charging, pen and pedal ports sit on different sides, so cables do not tangle or block the display.

Awgem says a full charge takes about 2.5 hours and gives up to 200 consecutive welds at maximum power, with a low battery warning and thermal protection. For users who value fine control and tidy cables, it is a good option. Test on scrap strip before welding cells, and turn the knob up slowly until the weld peels off with a firm tear. Keep it charged and let it cool between long sessions. Wear eye protection and work on a non-flammable mat.