A
[DIY] AWithZ U3 Pro spot welder — a home-made spare battery for a cordless drill, 21700 pack welding, efficient welding, twice the result for half the effort
AWithZ Official · OfficialFollow
![[DIY] AWithZ U3 Pro spot welder — a home-made spare battery for a cordless drill, 21700 pack welding, efficient welding, twice the result for half the effort · 1](https://cdn.awithz.com/assets/_derived/w480/community/works/d085/cover.webp?v=381542e7.q82 "Video")
Bill of materials
Welder, accessories, consumables and parts used in this build; quantities and specs are editable Download BOMAWithZ official
Third-party partsFrom the creator’s parts list, grouped by category; links to third-party stores
Hand-built 20000mAh power bankOther parts
×
Third-party
18650 cellsCell
×
Third-party
Description
[DIY] AWithZ U3 Pro spot welder — a home-made spare battery for a cordless drill, 21700 pack welding, efficient welding, twice the result for half the effort! #Compact #WeldingEquipment #ElectronicsHobbyist #GoodFinds #ApplianceRepair
Bill of materials
| Hand-built 20000mAh power bank | |
| 18650 cells |
Li-ion safety
DIY lithium packs can catch fire: check cells for shorts before welding, always add a BMS, never skip insulation and fusing on high-current builds.
Ideas for you
02:14Brushless motor turned monster fan, part 2 done. Installed + tested in one go, the sound takes off on the spot🔥
02:06DIY monster fan | Hardcore conversion of a drone brushless motor into a monster fan🔥 Step-by-step tutorial, a spot welder builds super-strong airflow💨, enough wind to take off — the summer cooling wonder
01:52Avoid the pitfalls in 1 minute! Beginners building a pack — 3 steps solve the core problems: set the series count ➜ set the parallel count ➜ lock in the BMS. With the AWithZ H2-2026 handheld, even a newbie can weld a finished-grade pack and get safely to the end🚗