Description

The FNIRSI SWM-20 is a professional-grade portable spot welder built for precision battery pack assembly, repair work, and DIY metal joining. Delivering up to 1200A peak current with dual-pulse technology, it produces clean, reliable welds on nickel strips, iron, stainless steel, and copper without the bulk of a bench-top unit.

Powered by dual A-grade 5000mAh battery cells, the SWM-20 supports up to 1,500 welding cycles per charge and doubles as a 5V/2.1A USB power bank, making it equally useful in a workshop or out in the field. A 2.4-inch TFT color display with rotary knob control gives real-time visibility into voltage, temperature, and welding parameters, while 10,000+ adjustment levels allow precise tuning for every material and thickness.

The dual-pulse mechanism works in two stages: a primary pulse removes the oxide layer from the material surface, and a secondary pulse delivers the actual weld, resulting in a cleaner and more mechanically sound joint compared to single-pulse welders. Four preset combination levels provide starting points for common materials, and fully adjustable preheat, pulse width, interval, and continuous weld count settings allow the operator to dial in parameters for less common materials or thicknesses.

For technicians in Karachi assembling lithium battery packs for solar UPS systems, repairing e-bike batteries, or building custom 18650 packs, the SWM-20 delivers bench-quality results in a palm-sized, rechargeable form factor.

Why Choose the FNIRSI SWM-20?

Pakistani repair workshops and hobbyists have long had to choose between underpowered budget welders and expensive imported bench units. The SWM-20 bridges that gap. It carries 1200A output, professional dual-pulse control, and an 8-in-1 safety protection system in a compact, battery-powered device that charges via USB-C. The built-in power bank function means the unit serves double duty on a job site, and the auto-shutdown timer and comprehensive protection circuit make it safe to use in workshop environments where unattended tools are a concern. Whether assembling solar storage packs, performing phone battery replacements, or doing e-bike battery repairs, this tool delivers repeatable, professional-grade welds without compromising on portability.

FEATURES

Delivers up to 1200A peak current output for strong, consistent welds across a range of materials and strip thicknesses up to 0.5mm.

Dual-pulse welding technology uses a primary pulse to strip the oxide layer from the material surface and a secondary pulse to form the weld, producing cleaner and more reliable joints compared to single-pulse welders.

Supports welding of nickel-plated steel up to 0.4mm, plain steel up to 0.5mm, pure nickel up to 0.25mm, iron up to 0.3mm, and copper and nickel-plated copper up to 0.1mm.

10,000+ ultra-fine power adjustment levels allow precise matching of weld energy to material type and thickness.

Fully adjustable welding parameters including preheat duration, pulse width, pulse interval, and number of continuous weld points.

2.4-inch TFT color display provides real-time readout of voltage, temperature, and all active welding parameters in a single view.

Rotary encoder knob enables fast and accurate adjustment of parameters during operation without menu navigation.

Dual A-grade 5000mAh battery cells provide high power output, stable discharge performance, and up to 1,500 welding cycles per full charge.

2-in-1 design functions as both a spot welder and a 5V/2.1A USB power bank, allowing the device to charge other equipment when not in use for welding.

USB Type-C charging input at 5V/2.1A for fast and convenient recharging using standard cables.

Detachable welding pens use 99.9% pure copper tips for maximum electrical conductivity, durability, and efficient heat dissipation during extended use.

8-in-1 smart safety protection system covers over-temperature, undervoltage, overcharge, over-discharge, short-circuit, voltage stabilization, low-temperature, and impact protection.

Adjustable auto-shutdown timer from 0 to 99 minutes conserves battery and reduces risk in unattended workshop environments.

USB-C firmware upgrade support allows the device to receive performance and feature improvements after purchase.

Compact handheld form factor suitable for bench use, field repair, and on-site battery pack assembly.

SPECIFICATIONS

Model: SWM-20
Max welding current: 1200A
Welding thickness range: 0.1 to 0.5mm
Supported materials: Nickel-plated steel (max 0.4mm), steel (max 0.5mm), pure nickel (max 0.25mm), iron (max 0.3mm), copper and nickel-plated copper (max 0.1mm)
Adjustment levels: 10,000+
Preset combination levels: 4
Battery capacity: 5000mAh (dual A-grade cells)
Charge input: 5V / 2.1A via USB Type-C
Power bank output: 5V / 2.1A via USB-A
Display: 2.4-inch TFT color screen
Max welding cycles per charge: 1,500
Auto-shutdown timer: 0 to 99 minutes (adjustable)
Firmware upgrade: USB Type-C
Operating temperature: -5°C to 40°C
Storage humidity: Up to 80% relative humidity
Warranty: 2 years (direct purchase via fnirsi.com); 30-day return and refund guarantee
Includes: SWM-20 host unit, welding pens, replacement tips, USB-C cable, nickel strip sample, user manual