I still go to DigiKey et al for build/rebuild project parts but for my own hobby/educational use I keep a lot of chinesium parts on hand from AliX or order as needed.

 

New battery capacity nonsense on AliExpress. They're using mWh instead of mAh.

I calculate 21800mWh to be about 2400mAh. Still unbelievable in that formfactor.

 

Here is one that they are selling even on Amazon that testing has shown to be useless. It is far from being "Lo Noise" but it does amplify the noise...

 

I wanted some dual-winding inductors to experiment with integrated magnetics for interleaved buck regulators. Essentially, it is a common mode choke with poor coupling between the windings, to give leakage inductance of about 10% of the magnetising inductance.
Where could I possibly get a poor common mode choke?
So I ordered a selection of common mode chokes from AliExpress. Every one was exactly the inductance specified and the coupling between windings was so good I could hardly measure any leakage inductance.
Maybe one day I'll need some common mode chokes.

 

Interesting behavior of AliExpress LM3914. I was doing DORA testing of 30 devices I bought. I unintentionally exceeded the maximum power dissipation in bar mode, and LEDs started turning off. First it was LED #5, then #6 turned off. Can't reproduce because I fried the chip by putting the board in the wrong position on the test setup and haven't found another that did that.

 

Who are some good and trusted sellers at alliexpress? Is there any thread for that list?

 

Unfortunately, on AliX if they get a bad rating, they simply change their name and open a new store all the time. My strategy is to price shop. I've had only one really bad deal with a vendor who sold cheap then told me they needed more money before they could ship. "Bait and Switch" which is a highly illegal business practice in most places. Told by AliX customer support that the vendor would be penalized for it, but it never happened and the vendor is still doing it as far as I know. Other times I had issues I was refunded by AliX and that is way too often. Prices have increased but shipping time has decreased. I still do business with them monthly for mostly hardware and the occasional module. Hard to beat their prices on small modules as most are cheaper than you can buy the components to build yourself. Caveat Emptor! But if you have the patience to put up with it...

 

Who are some good and trusted sellers at alliexpress?

From my experience, even sellers you had a good experience with can let you down later. I experienced this with a seller who sold 18500 Li-ion batteries. My first purchase from them were okay (about 90% of advertised capacity). Bought from them again, thinking I'd get good batteries again. I was mistaken. The newer batteries were advertised at a slightly higher capacity (2Ah vs 1.6Ah) and capacity was disappointing.

EDIT: Of the batteries I tested, capacity was 0.8-1.0Ah; or less than half of the stated capacity.

Is there any thread for that list?

There was a hread started for that purpose. I posted my reservations. That was before my experience with the batteries.

 

Other times I had issues I was refunded by AliX and that is way too often.

AliExpress has changed their refund policy. It used to be that you could request a partial refund. Now, AliExpress makes the determination. I stopped caring if a seller gets nothing for defective items that sort of work.

There have been times when AliExpress offered me a partial refund on fake Li-ion batteries (I was on a testing exercise). I objected when they did that on some rated at 88800mAh (yes, 88.8Ah!) batteries. I assumed the batteries were also poorly constructed and were a fire hazard.

 

From my experience, even sellers you had a good experience with can let you down later. I experienced this with a seller who sold 18500 Li-ion batteries. My first purchase from them were okay (about 90% of advertised capacity). Bought from them again, thinking I'd get good batteries again. I was mistaken. The newer batteries were advertised at a slightly higher capacity (2Ah vs 1.6Ah) and capacity was disappointing.

EDIT: Of the batteries I tested, capacity was 0.8-1.0Ah; or less than half of the stated capacity.

There was a hread started for that purpose. I posted my reservations. That was before my experience with the batteries.

Thank you. Actually, my experience with Alliexpress was not satisfactory. I sources some sensors years ago. Some turned out to be non-functional.

 

my experience with Alliexpress was not satisfactory

Are you basing your feelings on a single transaction?

For each of the items I posted about, there were 10-20 (or more) other transactions that were satisfactory.

 

Yeah, I bought some FETs that were correctly marked but turned out to be NPNs... But I did receive full restoration of what I paid. NEVER depend on the quality of chinesium components! Good for tinkering with but NEVER use them for replacement parts or actual circuit development or inclusion in working circuits. Caveat Emptor!!! In fact, with the recent price increases, components are generally as cheap or cheaper at DigiKey these days sans the shipping additions if below the free ship minimum so no incentive at all to buy them like it was before.

 

It used to be that you could request a partial refund.

I've never requested a partial refund but have been offered them instead of returning the defective parts or shipments that were received short of what was ordered. Their packing for shipping leaves a LOT to be desired and often comes damaged with pieces missing. I will say though that more expensive (>50USD) items do come better packaged and survive shipping better. So far, none of those more expensive items I've bought had shipping damage issues even when packaging arrived a bit battered and torn and are typically received quicker as well. Most defective parts, once I went through all the hoops required to provide evidence of being defective, I did receive full reimbursement without having to return. Return is at the buyer's expense BTW in all cases I've encountered hence I haven't bothered to do so. My wife has heard me doing more than a bit me of grousing, cursing, and grumping around over AliX problems.

 

Their packing for shipping leaves a LOT to be desired and often comes damaged with pieces missing.

I've had a couple issues with their combined shipping. On one package, there was a hole and two tools I bought were lost. I didn't think to take a picture of the hole before opening, but they took my word on it and reimbursed me. Unfortunately, the replacements I ordered costed more.

Return is at the buyer's expense BTW in all cases I've encountered hence I haven't bothered to do so.

In the past, they offered free return shipping on one item per order. I never considered that option because my time was more valuable than filling out the customs forms and standing in line to mail.

 

The metal used in the box for these clips is about 0.015" thick and is easily dented/bent.
https://www.aliexpress.us/item/3256...OlLqfE&gatewayAdapt=glo2usa#nav-specification


The box mine was packed in was mangled.

It was in a bag with a dozen other items, but I think it was mishandled before being combined with the other items.

The returns/refund form only allowed for a return with refund (and I needed to pay for return shipping), so I had to chat with a representative to submit a request for a partial refund. AliExpress asked for more information, so I reposted the pictures I sent to the representative. They issued a full, no return refund. I didn't bother saying I'd accept a partial refund because they had already submitted a refund request to the card I used.

 

I bought 6 of these:
https://www.aliexpress.us/item/3256...t_main.17.94f71802OlLqfE&gatewayAdapt=glo2usa

One didn't work. Upon inspection, I found that one of the LEDs wasn't soldered (at all). I put a piece of paper under the leads to show that:

Not certain if that's the only problem. I haven't soldered the LED. The IC used doesn't have any markings and I haven't bothered to trace the circuit.

I wanted a partial refund for the defective unit. The online form only allowed refund/return (but with free return shipping). Since I only wanted a partial refund, I chatted with a representative. AliExpress asked for additional information, so I posted the pictures I uploaded for the representative. They (quickly) issued a full refund. I didn't bother saying I'd accept a partial refund because they had already submitted a refund request to the card I used.

The sensors are flakey. They interact with fluorescent and LED light. I had to block ambient light from hitting the sensor for them to work. Otherwise, they oscillated between turning the output on and off.

 

China "We do not supply any war materials to Russia or Iran".
AliX - These are one of the rocket engine "toys" that we sell to Russia for their missles and drones.

Yep, they've been selling 1000s of similar ones to both. These are not exactly "Toys"! Good luck to both of them for buying these... not very mil spec or even aviation certified quality... Compartively cheap, but you get less than what you pay for...