The SUNKKO 738AL is a high-power, transformer-type battery spot welder purpose-built for assembling and repairing lithium battery packs (e.g., 18650/21700). Its hallmark is the telescopic welding arm (rocker arm) that gives you stable, repeatable fixed-head welds, plus handheld welding pens for flexible tab work on awkward geometries. Multiple pulse modes (2/4/6/8) and adjustable current let you dial in heat input for different tab widths and materials. Kits are commonly sold with a 73LA/73LB telescopic arm and a 70BN/73B series handheld pen, along with a foot pedal and consumables, so you can switch between fixed-head and pen welding in seconds.

Key Features

• 3.6 kW class transformer welder designed for nickel & nickel-plated steel battery tabs. (Not for copper/aluminum.)

• Telescopic arm gives a 95–160 mm reach for precise, pressure-controlled fixed-head welding.

• Handheld welding pens included in common bundles for mobile spot-welding on large packs.

• Multi-pulse control (2/4/6/8 pulses) and adjustable pulse width for clean, low-splash nuggets.

• Dual-use thickness capability: up to 0.30 mm nickel-plated steel on the fixed head; up to 0.20 mm on the handheld pens.

Typical Applications

• Building multi-row lithium packs (e-bike, power-tool, UPS, robotics)

• Re-tabbing cells; repairing series/parallel links and bus bars

• Small production runs where repeatability and speed matter

What’s in the Box (common 738AL bundles)

• 738AL main unit

• 73LA/73LB telescopic arm assembly

• Foot pedal switch, welding head/electrodes, basic accessories/consumables
  (Contents vary by seller—check your specific package.)

Detailed Specifications

• Model: SUNKKO 738AL

• Input voltage: 220 V variants

• Rated power / capacity: 3.6 kW / 3.6 kVA class.

• Welding current (adjustable): commonly specified as 50–900 A, with some listings specifying 120–1100 A (range varies by seller/spec sheet).

• Pulse modes: 2 / 4 / 6 / 8 pulses; typical pulse-time ranges:

  • 2-pulse: 1–10 ms

  • 4-pulse: 2–20 ms

  • (overall time window) 8–80 ms

• Fixed-head (arm) welding capacity: 0.05–0.30 mm (nickel-plated steel).

• Handheld pen welding capacity: 0.05–0.20 mm (nickel-plated steel).

• Telescopic arm reach: 95–160 mm adjustable.

• Supported materials: pure nickel and nickel-plated steel tabs (not suitable for copper or aluminum).

• Body size / weight: approx. 140 × 245 × 200 mm; ~5.6 kg.

Use & Setup Notes

• Match the machine to your mains voltage (order 110 V or 220 V version accordingly).

• For best nuggets, start lower on current/pulse counts and increase gradually based on peel tests. Multi-pulse modes help on thicker or multi-layer tabs.

• As with other SUNKKO 7-series welders, give brief intervals between consecutive welds and avoid copper/aluminum tabs. (General guidance from 7-series manuals.)