Anyone else burned by a power bank? I went for a battery spot welder — power-bank freedom! Totally hooked

Li Dapang tears down a “60,000mAh” power bank and finds only three pouch cells with foam on either side; wants to hand-build one from the 18650s he “grew” (2000mAh); solder paste won’t take, so a buddy recommends a battery spot welder (U3, auto, gear 5) — one tap does it, “you’ve got to invest when it’s worth it”, first he’ll explore what else it can weld; the creator pinned the official store link

Burned by a power bank: labeled 60,000mAh, opened up in shock — three lithium-polymer pouches in the middle with foam sandwiched on both sides, no wonder it only charges the phone two or three times; a Douyin expert hand-builds power banks from 18650s, “the batteries we planted are ripe” (gag: picking cells off a tree), fully ripe means 2000mAh, picked 8 good ones; after ages of soldering, a serious problem: even with solder paste it won’t take, the solder won’t wet; a buddy tells me to use this device — a battery spot welder (nameplate U3, 4.2V/650A MAX, Type-C 5V/2.1A in, USB 5V/2.4A out, 11000mAh, Juequi Technology); how to use it? Fully automatic, set to auto, gear 5 and go; lay on the nickel strip, can’t wait for the first tap, “oh!”, one tap and it’s done; you’ve got to invest when it’s worth it, good gear just works; check whether the weld is perfect; first he’ll explore what else it can weld, the power bank can wait. Pinned comment: friends who grow batteries need this spot welder, it’s in the storefront, official shop. Comments: a dab of toilet-bowl cleaner and it solders, is a device worth buying for one weld?; can it weld LED strips; blade batteries; the one I made has 4 cells at 20,000 each, the foam is a placeholder for the large-capacity version.

Outcome

Steps4 steps · click a frame to jump

1. 
   1. Tear down the “60,000mAh” power bank: three pouches + foam

   Burned by a power bank — labeled 60,000mAh, opened up in shock, three lithium-polymer pouches in the middle with foam on both sides, no wonder it only charges two or three times.

   00:00 – 00:16
2. 
   2. “The batteries we planted are ripe”: pick 8 × 2000mAh

   An expert hand-builds power banks from 18650s; the batteries we planted are ripe, pick a few first; fully ripe means 2000mAh; some aren’t ripe, wait a few more days; picked 8 good ones.

   00:16 – 00:39
3. 
   3. Even solder paste won’t take; a buddy recommends the U3 battery spot welder, auto, gear 5

   Soldered for ages, won’t take, won’t wet; a buddy says use this device, called a battery spot welder (nameplate U3 4.2V/650A, 11000mAh); fully automatic, set auto, gear 5 and go.

   00:39 – 00:56
4. 
   4. First tap: one tap does it; you’ve got to invest when it’s worth it

   Lay on the nickel strip, can’t wait, first tap, oh!; one tap like this does it; you’ve got to invest when it’s worth it, good gear just works; check whether the weld is perfect; explore what else it can weld first, power bank later.

   00:56 – 01:25

Bill of materials

Creator’s tips

• Solder won’t wet 18650 terminals — spot-weld nickel strip straight on 00:42
• Beginners can use auto mode, gear 5, one tap 00:42

Pitfalls

• Even solder paste won’t take on an 18650 00:42
• Fake-rated power bank: 60,000mAh turned out to be three pouch cells plus foam 00:00

Li-ion safety

Quotes