A Tale of Two $30 Load Banks: 60V, 150W, one awesome, one junk

It’s rare to find something this interesting in the Chinese Electronics realm.

What I have here are two different units - that look identical at first glance!  And, actually, they look identical until you really dig in and stare at details.  But one is really, really good, and one is so comically bad that it probably won’t last an hour in actual use before blowing up.

This is a companion discussion topic for the original entry at https://www.sevarg.net/2018/06/10/a-tale-of-two-30-load-banks-60v-150w/

(Comments from Blogger)

2018-06-11 by zeroair

Maybe the “fake” version was just an early revision where they found problems and corrected with the “real”? That would at least answer your question of "Why is there a nearly identical fake that’s functionally dangerous?"

I wish there was something like this that had serial connection, and also went up to higher than 150W. And also wasn’t expensive. (lol)

2018-06-11 by Russell Graves

I think the problem is mostly in the software - the hardware does seem substantially identical, so I can’t imagine why it wouldn’t be decent with the right software. That doesn’t seem like a revision issue, either - why would you change the hardware to change the software?

There’s a story behind it, probably an entertaining one, just not one I’m ever likely to hear.

A serial out would be nice, and I expect the board could do it, but I’m just not up for firmware hacking on something I don’t have design diagrams for. You could probably reverse engineer one, build your own, and get a serial port on it!

2018-06-23 by Jan

More likely a company has copied someone else’s design (PCBs are easy to clone) but they couldn’t get the firmware (read-protected chip), so they hacked up something of their own so that they can sell it. It (kinda) work so off with it on the market…

Very common scenario in China.

2018-06-23 by Jan

If the seller has pictures of the legitimate unit and sends you a fake one, complain. They didn’t send you the unit pictured.

Russell, if you look carefully, most of the eBay sellers (didn’t check on AliExpress) are not using pictures of the actual units but stock photos. Worse, in many cases the pictures are not even of the same unit! E.g. one view shows the polarity markings on the input jack and another view of the PCB shows the board without them. So making such claim to eBay is going to be a lottery.

I would say it is best to spend one’s money elsewhere than to bother with these … Or even build your own - power transistors, fans, heatsink and similar can be scavenged from old computer hardware and the rest either costs peanuts or most people have it in their junkbox already.

2018-06-23 by Russell Graves

I’ve certainly seen sellers with inconsistent photos, but I’ve found some with consistent photos as well. And, at least currently, eBay sides with the buyer, so if you buy it and it’s the fake, and complain it’s “not as advertised,” they should get you your money back. But, yes, it’s a tough balance.

I’ve got another review in progress for the “purple fan” one of similar specs, and it’s an absolute rubbish unit. It’s better at blowing MOSFETs than it is at anything else, in addition to being an analog unit with a digital front end that works very poorly. I still need to stick a scope on it and see why it’s blowing stuff up, but I’m now on my fourth MOSFET just trying to finish the review, and I haven’t taken that unit (rated to “200V”) above 40V yet…

2018-06-23 by arantius

Love this post but sadly only a few minutes searching found:

Imgur: The magic of the Internet

This unit has a polarity marking, plus a track outside the heatsink. Legitimate or no?

I also see what looks like a more readable display plus rotary encoders on another model that seems to be “the purple fan one” – eagerly awaiting that review.

2018-06-23 by Russell Graves

That’s yet another revision, probably of the fake one. It only has a two pin power connector, as opposed to the four wire on the ones I reviewed. I’d avoid that one.

The “purple fan one” is absolute junk and should be entirely avoided.

2018-06-25 by arantius

I’m more convinced there’s several revisions, perhaps by the same original source (other commenters suggest the “fake” one is the first revision?), after finding:

Imgur: The magic of the Internet

So similar in many small details, but text->graphic LCD and buttons->rotary encoder. Four wire; so many other similar details (buzzer and all connectors along the back) the same; latest revision?

2018-07-13 by Unknown

Russell: I bought one of these using your guidelines from diybox on eBay. The photos on the webpage were consistent with a legitimate tester.

The one I received had no polarity legend by the power plug and the trace goes outside the heatsink leg. However, there is no text in the corner.

I powered it up and it does have a “Welcome to use” splash screen. The back side of the PC Board is very different from yours. The NTC label is at right angle to yours. Button 4 does reset.

Do you think this is a real one or fake? It sounds like fake to me. I just got it today.

2018-07-15 by Russell Graves

Interesting - that sounds like a new revision. Do you have photos of it? Someone on Reddit got a newer version as well and it seems to be legit.

2018-07-28 by Unknown

It’s a fake. I have one like that, it shorts on load off 3 of 5 times, no firmware version, calibration menu, etc.

2018-10-30 by Gnarlodious

Here’s my sad story. At the time of this publishing I ordered a unit from a Chinese seller, making sure the photo showed the newer revision, but what I received was the older model. I argued with the seller, who could barely communicate in English, and certainly did not understand that they had sent the wrong item (because it was a swindle). Finally the seller told me to return the unit registered mail, at my own expense, and he would refund my $30, which I did, however the return postage to China was $49. I was sure I could get a “return shipping refund” from PayPal since they offer the service as protection to buyers. After 29 days (Paypal’s limit for the refund is 30 days) the item was still stuck in China customs. PayPal refused to refund my shipping cost because “stuck in customs” is not a valid claim. So I lost my original $30 for the device and $49 for return shipping. People in the know have told me that due to worsening trade relations with China they are ignoring eBay returns and that in fact the subsidized postage from China may end next year. So I lost my money and still don’t have a programmable load.

2019-01-28 by Unknown

I have the legitimate unit and I wonder whether or not it makes sense to purchase separate tester (like TEC-06 or EBD-M05) just for testing the 18650 cells.

2019-09-12 by Werner

it’s also possible that you buy a fake of a fake unit when you buy at ebay chineese sellers.