U3 Pro Support center
Card-size welder with 5000/7500/11000mAh options, 2" color screen, tuning combos and smart pen support; welds 0.35mm nickel-plated steel / 0.1mm copper; doubles as a USB power bank.
First make sure the pins are pressed firmly and the surface is clean; start low and step up — 0.1–0.15mm Ni-plated steel usually needs only a low-to-mid level. Look up settings by cell model × material in the WeldWorld parameter lookup.
Pins are consumables — dress or replace them when welds enlarge, spark often or blacken noticeably; see the manual's pin-change section and the Academy videos for steps.
For lithium models, top up to 50–80% every three months; avoid heat and long-term storage at full charge.
Host warranty of 1–2 years by model (2 years for UF20B/UK3/HF7, 1 year for UK1/UKF10; accessories such as welding pens excluded); 7-day no-reason returns; invoices available for genuine flagship purchases
More FAQs in support center FAQ.