A ¥25 ‘brushless’ handheld car vacuum bought online — opened up, it really is a brushless motor

Teardown of a ¥24.9 brushless handheld car vacuum: Dyson-style shell, 7.4V 80W brushless motor, 2000mAh pack with BMS; the old cells read 23/16mΩ and 4.06/3.88V — a big voltage gap — so they’re swapped for DMEGC 25P salvaged A-grade 2500mAh, spot-welded with an AWithZ U3 on manual, gear 4, and the airflow is clearly stronger

A brushless car vacuum recommended by a follower, ¥24.9 paid with free shipping, probably export overstock. Try it first: the body looks like a Dyson, various nozzles included; two suction levels, Type-C charging; it can lift a phone, with the concentrator nozzle it works as a blower and pops a balloon, and it swallows large screws. Teardown: the clips are so tight they have to be cut; the motor is 7.4V 80W and really is brushless, with a brushless controller board, push-button switch, 2000mAh pack (brand XACN, with BMS) and a Type-C charging board. The old cells out of the pack: the first reads 23mΩ and 4.06V, the second 16mΩ and 3.88V — big spread in both resistance and voltage, no wonder it dies in minutes; don’t buy no-name cells. Replaced with DMEGC 25P salvaged A-grade 2500mAh, spot-welded with an AWithZ U3 on manual trigger, gear 4; with the new cells the airflow is much stronger. 129 comments: top ones ‘the price jumped straight away, it’s ¥49 now’, ‘one review and the price goes up 4–5×’; many asking for the link / shop; someone shared a teardown trick: warm the tail with a hair dryer and it pulls straight off, three screws come out easily (no need to cut the clips).

Outcome

Steps6 steps · click a frame to jump

1. 
   1. Bought for ¥24.9, Dyson-style export overstock

   A brushless car vacuum recommended by a follower, ¥24.9 paid with free shipping, probably export overstock; play with it first, then tear down; the shell copies a Dyson.

   00:02 – 00:37
2. 
   2. Try-out: two suction levels, Type-C, lifts a phone, pops a balloon, swallows screws

   Various nozzles; two suction levels, Type-C charging; it can lift a phone; with the concentrator nozzle it works as a blower and pops a balloon; suction is decent, large screws go in.

   00:38 – 01:45
3. 
   3. Teardown: cut the clips; 7.4V 80W brushless motor, controller board, 2000mAh pack

   The clips are so tight they have to be cut; the motor is 7.4V 80W and really brushless; brushless controller board, push-button switch, 2000mAh pack, Type-C charging board.

   01:45 – 02:15
4. 
   4. Old cells tested: 23/16mΩ, 4.06/3.88V, big voltage gap

   The pack brand is XACN, with a BMS; old cells out: the first reads 23mΩ and 4.06V, the second 16mΩ and 3.88V; the resistance spread and voltage gap are far too big, it dies in minutes; no-name cells really aren’t worth buying.

   02:15 – 02:49
5. 
   5. Swap to DMEGC 25P 2500mAh, AWithZ U3 on manual, gear 4

   A big voltage gap badly hurts performance; swap to DMEGC 25P salvaged A-grade 2500mAh; spot-weld with the AWithZ U3, manual trigger, gear four.

   02:49 – 03:10
6. 
   6. Airflow clearly stronger after the swap; wrap-up

   With the new cells the airflow feels much stronger; that’s the try-out and teardown.

   03:21 – 03:41

Bill of materials

Measured on camera

Creator’s tips

• Test the old cells’ internal resistance and voltage first — a big voltage or resistance spread is why it dies in minutes 02:28
• Comment: warm the tail with a hair dryer and it pulls straight off, the three screws come out easily, no need to cut the clips

Pitfalls

• The clips are so tight they have to be cut (a comment gives a damage-free method) 01:53
• No-name cells have big resistance and voltage spread 02:37
• Comment: the price went up to ¥49 after the review

Li-ion safety

Quotes

Cost & time