I ticked off a sponsor

I have done a fair number of sponsored videos the last two years. Usually it goes well, but when I tried to get a company to fix a problem with their product, I hit an impasse.
Though I don't try to hide the company name, I deliberately didn't mention them in anythign I said because I don't want this video to show up if you search for the company -- I'm not out to hurt them. So you can see the company name and logo on the battery box, but that probably isn't enough for KZbin's search algorithms to pick up on that.
This is a revised version of the video, see explanation starting at 9:05
Also see the follow-up on this video: • Inverters don't like p...

[@BlackFighter_95]

I am a developer for frequency inverters and I fully agree that this behavior is normal. The reason is that with that massive overload, the output inductance saturates - this could already lead to oscillation. Additionally, controlling a saturated inductance and a dropping battery voltage is extremely difficult. To prevent an overload in this case, the physical size and cost of the inverter would probably be increased by factors (assuming this device is already at a good quantity). So there are only two possible reactions that a device with that size on this load can do: Either shut off or accept some oscillations. On the other hand: the input circuit with the capacitive voltage dividing on the power meter is a very bad design practice, although this is done a lot especially in cheap products. When testet according to standards that are mandatory for sale in the EU, most of these products fail. All products must withstand some harmonics/flicker/emi/...

[@matthiasrandomstuff2221]

EcoFlow just got back to me with this explanation here: link.medium.com/tDYDK9mTjvb Apparently, there is a protection circuit that forces the inverter transistors off when a certain current is exceeded, which appears to be independent of the normal control loop. This protection circuit leads to the oscillations.

[@sucotronic]

Adding to that, powering devices with two diodes and a capacitor is cheap but TOO DANGEROUS to use. I consider it the cheapo way to power anything, so I strongly recommend to not buy/use anything powered in that way ;)

[@testingoyay4648]

@@sucotronic what's the recommended way for things to be powered with such devices?

[@sucotronic]

@@testingoyay4648 batteries or transformers

[@fabiofoltran4361]

I mean I see a lot of people praising matthias integrity but I think there was a misunderstanding here ..as you said desining this kind of products it's really difficult so when overloading the inverters with such large currents, transients are to be expected ....ecoflow isn't a bad company ..much better that other portable batteries manufacturer .if not the best

[@matthiasrandomstuff2221]

This is a revised version of the video. The original version inadvertently made the oscillations look 4x bigger than they were. Explanation at 9:05 into the video.

[@ChongMcBong]

no worries, thanks Mattias :)

[@thesushifiend]

I thought there was a glitch in the matrix, since I was sure I'd watched this hours before. Thank goodness I'm not crazy. Well I am, but not because of this!

[@ionstorm66]

To be fair, the old waveform is what the KillaWatt was getting!

[@propertystuff7221]

TYVM for being honest about this problem. I'd considered getting one of these to run my power tools AND charge my phone at the same time. That woulda been a very costly mistake.

[@pokojnitozo2360]

I would love to see what happen when you have already some load(200+W), and then start circular saw. This can make problem go away or it can make it 10 times worse. And it would be closer approximation of full house backup scenario.

[@DustinFife]

I’ve been following Matthias for about 10 years now, and I remember the first time he did a sponsored video I was pretty upset. I thought he had sold himself out. I subsequently have watched all of his videos, especially the ones where he talks about sponsorship. I really appreciate his integrity. And this is a great example of a class act on his part.

[@atlantic_love]

Yeap. It is difficult to findi any reviews of anything out there anymore, that aren't full of bias and neglecting to mention the bad things.

[@bmich281]

Yep the Dewalt sponsorship, John Heitz got the same sponsorship.

[@davidduffy9806]

I’m a similar time line, he’s a good fella

[@TravisTerrell]

IIRC, he was as upset as you. Ha

[@201hastings]

You were upset about a stranger making money off a sponsorship?

[@MeisterKleisterHeisstEr]

About VPN sponsors, Tom Scott made a great video detailing how a lot of their claims are dishonest.

[@dustysparks]

He still ends up doing spots for Nord, but I can see how they changed the talking points, so they've learned something at least...

[@IstasPumaNevada]

I will forever fondly remember gay pirate assassins.

[@user-fs3dg1po2z]

Look up Naomi Brockwell's video about VPNs if you want to know just how unscrupulous most of them are

[@ewicky]

It doesn't take an obnoxious Tom Scott video to understand that VPN ads are lies

[@damienwills8658]

@@ewicky what do they lie about?

[@jasonostermann9294]

There were some good comments on the prior version of this video. 1) The neutral fault: as mentioned elsewhere here, you must use a differential or isolated probe for this kind of testing. Otherwise you're tying mains ground to generator neutral which is a terribly bad idea. Best case that causes a ground loop and will trip an AFCI breaker. Worst case your scope is now a bypass and/or ground reference for the generator and you'll have unknown amounts of current running through the scope ground plane. The test was done incorrectly. I've inadvertently made similar mistakes when checking the output of my gensets and working too quickly, resulting in exciting sparks and breakers throwing, but I blamed myself and not the products. Neutral is not the same as ground!!!! 2) The line noise is the result if the inductive load of the motor. This happens any time an A/C motor starts. The effect on mains is mitigated because the power distribution system acts as giant capacitors. But this is why lights flicker or dim when a large air conditioning unit kicks on. As noted elsewhere, when sitting on a generator, there's nowhere for this inductive load to go and the generator can't spit out enough power instantly to manage it. The table saw is better because the motor is probably not all that much larger than the circular saw, but you have dramatically larger output buffering with those two units than the one small unit, plus the table saw starts slowly. The real point of the 240V on the table saw is for motor torque, not for higher power output. You'll see this same noise on *any* generator - battery or gas. It's not a product fault, it's a use case fault. This is one big reason why large (i.e. >1/4hp) A/C motors should run from *traditional gas* generators. There it's just a spinning rotor - no electronics except for the voltage regulator - so the inductive load gets (partially) sunk into the magnetic fields and there's no electronics to damage. You can hear the two motors (gas and the tool/appliance) fight each other at startup, then run in sync. Generator companies, especially consumer grade, and double especially this new wave of battery ""generator"", are built for common household use cases - refrigerator, lights, TV, not much else. A wood shop is not the designed use case! Sadly their advertising does say "power tools", but their example is a hand drill. And the inductive load of a hand drill startup is far, far less than a circular saw. So sure, they need to be clearer in their marketing, but running a wood shop off of a battery power pack is a highly unusual use case. And construction crews are *not* going to be buying this kind of thing - they're buying plain old gas generators. Even in that use case, the only thing plugged in will be motors - saws, compressors, drills, mixers, etc - which don't care about noise very much. So as long as the genset output is sufficiently protected so it doesn't get killed by the noise (which appears to be the case), then they did things correctly. You've got good material, but you need to better understand what you're testing and what your results actually show before drawing conclusions.

[@familei3349]

Totally agree. I was elated the first time I witnessed the signal of a hairdryer on an o-scope. Didn't have a differential probe either. One thing I didn't do is make a video and blame Tektronics for my results!

[@meko1896]

I stopped this video less than halfway through to see if anybody else caught this. Of course, they did, and Jason did a very excellent job of explaining things. I would have probably gone way overboard. The only thing I would add is if you want battery solution to use power tools, get a heavy-duty transformer inverter that is made for these types of loads. Any nontransformer inverter will have the same characteristics, if not worse. The issue with Ground vs Neutral is well documented all over the internet, separate problem. As always, there is a disconnect between design/engineering and marketing. Unfortunately, we see this all too often.

[@calebpurvis6195]

I'm with you most of the way, and I understand your point about using non-inverter generators. However I will say I'm seeing quite a lot of stir in the industrial use space for inverter generators. So I think the focus should be on solving the problem vs saying 'you don't understand and use case, that wouldn't happen'. I think things like noise constraints and sites that have to deal with emissions limitations (I'm thinking of confined spaces, low grades (holes, pits, ect...), Flammability limitations, ect.... not really the miniscule environmental impact.). I think we are going to see battery 'generators' start becoming more common as battery tech/capabilities improve.

[@han5vk]

@@calebpurvis6195 Everything will be affected by a huge current spike like that. Motors don't care.

[@BlackEpyon]

My hobby is retro computers. Since computers tend to have their 0v rail tied to chassis, and thus to earth ground, this isn't really an issue for me.

[@josuelservin]

Test like this actually make me more confident about buying one of this boxes, I prefer to know the limitations of the equipment I use without having to blow up stuff myself. I love when companies listen to feedback and use it to improve, it's a shame they weren't willing to do so this time, I hope you can get a sponsor who does.

[@rklauco]

Well, the problem here is - there is not much they can technically do about the problem. Other than create absolutely new inverter design, that would not fit to the enclosure and would be horribly inefficient for loads that are below its rating. So, it's always a trade-off... In general, the business case here is - people that use circular saw will not use it in parallel with AC powered sensitive devices - because they are somewhere at construction site, etc. And small devices (laptops, phones, etc.) have separate DC output (100W USB-C, for example) on the front panel that will not be impacted by start of the saw at all.

[@MyShakeweight]

@@rklauco I think it would be reasonable for the company to add a warning about this specific use case rather than ignoring it so people know what precautions they should be taking.

[@nraynaud]

@@rklauco Can you explain why they can't filter their way out of the problem? A simplistic look at things is that they have to produce one frequency, so everything higher would be filterable, wouldn't it? (I hope to learn something new in the answer, it's not a know-it-all question)

[@robertdillon9989]

@@rklaucohow do you know that? You don’t. Unless you are assuming that all small devices have a BMS that provides overcurrent protection, which they don’t. Predicting the behaviors of construction workers is best left to Sociologists.

[@randybobandy9828]

Pro tip: don't try to run massive inductive loads( saws and power tool start ups) on a inverter that has a High frequency like these ones. This isn't a defect, it's a limitation of the tech. Low frequency inverters are the ones that can handle these type of loads but they are WAY more expensive.

[@Vsor]

Matthias proved his integrity twice in one day!

[@rpm773]

3 times, if you count that he made the video to send to the prospective sponsor.

[@markandrews7701]

People make mistakes. It happens and there is nothing that can be done to prevent it. What a person does when they make a mistake defines their character. My hat is off to you, Matthias, for admitting your error, explaining it, and then correcting it. That is what integrity IS. Most people do not have the strength to admit when they are wrong and that is a sad commentary on society.

[@randybobandy9828]

Not really

[@chrisparker9886]

You need to look up the meaning of integrity! 🥴

[@zacharymorris9917]

This is the opposite of integrity

[@krazed0451]

As you mentioned, it is an extremely minor issue, I'm surprised they weren't happy with your proposed warning of not running power tools and sensitive electronics simultaneously... It's still a fairly strong recommendation overall.

[@absurdengineering]

“An extremely minor issue” lol. Since when is a current control loop going unstable when it’s doing what it’s supposed to do (limiting current) an “extremely minor issue”. Don’t be an apologist for them. That’s the sort of a fail EE students would get lots of points taken off if it was a class project. What you claim as minor is a very basic engineering fail that anyone competent would be ashamed of, not apologizing for.

[@krazed0451]

​@@absurdengineering What scale was the scope in? How wide was the current clamping window?

[@Geopolitic157]

Matthias is brutally honest, even if it hurts himself. A breath of fresh air to integrity.

[@stevewilson6193]

He is definitely blunt, but do we know that other brands don't behave the same way? step it up Matthias! lets see you compare them

[@creativename2697]

I respect what he is trying to do, but unfortunately, in this case, this is actually completly normal behaviour of inverter boards and their necessary protection circuits. In fact, the oscillation he shows in this video by the newer version of the devices is actually impressive.

[@kitecattestecke2303]

The title of the video is clickbait as fk and he owns a scope but is not able to research enough to understand the details... Video is relative misleading ion the beginning. Goes to show how unusable KZbin is as a scientific sourcebook :-)

[@hellopsp180]

Agreed

[@crackthefoundation_]

@@stevewilson6193 Lol yeah the other brands would have burned down his shop

[@viceice]

Seriously, the Ecoflow looks like a well built product as it is. So what if it has limitations? Everything in the world has limits. The important thing is to document it well, and inform the users. Ecoflow needs to get on board with that.

[@Dextermorga]

I do not see any issue in my case. Thank you for letting us know. So do not use a saw on that thing and you will be ok 😊

[@ttkddry]

This is a typical case of over-promissing and under-delivery... I can imagine the discussions between the Marketing dept and Engineering... One of them is to blame and we all know who has been overpromissing :-). These companies hype up their products and I see sponsorship deals with influencers where they push the demo's beyond 'intended use'. There is a reason why established companies selling off grid inverters sell heavier and more expensive inverters...

[@absurdengineering]

@@Dextermorga”Do not use it on a saw”… man, that thing is a power source. If you can plug a load into the mains socket and have it behave decently, then this thing that is a portable mains socket should do it too. You’re excusing poor engineering.

[@JDHood]

Matthias, you are a rare being these days: A trustworthy man.

[@HexenzirkelZuluhed]

If I needed one of those, I'd still buy one. Better to know the limitations. Which in this case are acceptable in my opinion. Good and honest videos, as per usual.

[@matthiasrandomstuff2221]

I would not be dissuading you from getting one. Use it with power tool or with tech, but not both at the same time and you will be fine.

[@dustysparks]

@@matthiasrandomstuff2221 I think that's a fair assessment, it looks like a really SOLID unit all tolled.

[@theoztreecrasher2647]

@@dustysparks "Ask not for whom the bell tolls" - you will be told that it has tolled for your iPhone! 😱😜🙄

[@luminatrixfanfiction]

@@matthiasrandomstuff2221 It just occurs to me that you were testing with the circular saw without putting a load on it (i.e. resistance, cutting wood) so the power current would have been higher to maintain the saw's rotations against cutting something, leading to worse oscillation.

[@palleppalsson]

@@luminatrixfanfiction problem was just in the startup 39ms and no one starts a saw with load.

[@davidkelly1634]

The internet needs more people like Matthias. Thank you for all your honest content.

[@TheDoItYourselfWorld]

I am so happy that I watched this through. I am slowly setting up a fully off grid wood shop. But I may have some more sensitive tools in there. I had no idea that some tools could cause others to blow out. I wonder if those surge protector power strips would be harmed by this? My thinking is to have everything off unless needed to prevent such issues.

[@billide1463]

I very much appreciate your general approach to issues; you give each problem a thorough effort, as a result we all learn a lot. Keep the videos coming. senior from Ajax

[@justaworkeryup636]

I like that you called it a battery powered station. Not a generator as many channels do. It drives me nuts lol

[@PatJamesRicketts]

I use a lot of power tools and sensitive electronics (PC overclocking carpenter...) and I have been looking into a couple different brands of these power stations for off-grid use. Thanks for going in-depth on these units, and thank you for holding to your principals, your content and character speak for themselves. Keep up the awesome work!

[@gblargg]

I've always been way of running power tools on the same plug as electronics, and this confirms that they can cause issues. Good to know with certainty.

[@JeffGeerling]

4:14 - so you've built an FM radio transmitter! The drop off in response is a little disappointing, though using a circular saw on a portable battery bank is quite a bit of an outlier compared to the typical case of plugging in fridge, a laptop, and a couple other smaller appliances. Next time I talk to Ecoflow (I might be working on a solar project where they could be a sponsor), I'll be sure to bring this up and see if I also get the silent treatment. Hopefully not!

[@matthiasrandomstuff2221]

yes, the cicrular saw draws an insane amount of current for the first fraction of a second.

[@Nitecrow314]

@@matthiasrandomstuff2221 This may be the reason I find that brushed ebike motors have way more instant "grunt" than any brushless motors I have tried 🤔.

[@Lizlodude]

Ha as soon as he mentioned the switch I thought oh lol it's coupling over isn't it... Gotta love the auto setting, I really need to learn to use mine better.

[@MazeFrame]

@@Lizlodude I do not trust the auto-button on my scope anymore. Once made me chase ghosts before I noticed I was looking at 50ns.

[@marquisdemoo1792]

Not so, I was watching the Skill Builder's video this morning where he was explaining these battery boxes are great for on site, especially if the electrics are off. He was pushing the Ecoflow Delta Pro.

[@fokare]

This video summarizes why I been following this channel for so long. Continue with integrity

[@chefbob09]

Integrity cannot be bought.

[@Margarinetaylorgrease]

It can, I've got some in a box if you want to buy ;) Special offer 3 for 2

[@chefbob09]

@@Margarinetaylorgrease lol I said integrity not tegridy.

[@jTempVids]

Your review made me more impressed with the Ecoflow. I'm ok with that limitation and would gladly buy one if the need arises in the future. It seems like a very well built device. As you said, a simple warning in the manual would probably suffice, especially for the whole home model.

[@ColbyJohnson]

The company I work for makes controls for lots of industrial applications. The noise you are seeing in the output is (as you say at the end of the video) not that uncommon. One of the products we developed had a capacitive dropper power supply originally, but when (in this application) a motorized door was opened on the same circuit it would reset the controller almost every single time. Changed the design over to a switch mode transformer based power supply and the issues went away. In short, the noise you are seeing in the generated voltage is "normal" noise, and it is very much up to the other devices on the circuit to be designed with good enough protection to save themselves from these types of transients. On a positive note, laptops, desktops, phone chargers, etc should all be immune to this type of transient due to being SELV compliant (safety extra low voltage), which requires isolation from mains for end user protection. All devices that use the capacitive dropper power supply shouldn't have end user touchable connections because there's potential for phase reversal (line/neutral swapped).

[@matthiasrandomstuff2221]

Thanks for the explanation. Indeed, these capacitive dropping power supplies may have to go away due to inverter issues like this. If I hadn't already pinned my explanatory comment, I would pin this one (maybe I'll pin it later)

[@Lizlodude]

This is why I love the sponsorships you take. The fact that you won't stand behind something you have an issue with not only builds trust with you, but also with the brands who choose to work with you. If a company is willing to let you take their product apart and do tests on it, I respect their product far more than if they just paid someone to say it's neat. I'd expect that behavior from an overloaded inverter, so I suppose that isn't necessarily abnormal, but I would expect overcurrent protection to kick in before the waveform gets distorted enough to potentially damage other devices. I suppose that's why theirs can power much higher load stuff like power tools, where other inverters would just trip when you try to start one up. Maybe a 'safe' and 'high power' mode would work, enabling or disabling the OCP, or at least changing the duration it will trip on, and a simple warning about mixing sensitive and high-power devices on the same battery.

[@Anaerin]

"Pure Sine" inverters like this (and like UPS' and the like), along with the inverters for the 3-phase motors in EVs all work the same way. They use a microcontroller to make a high-frequency PWM signal to switch a pair of MOSFETS (or IGBTs). This is because FETs are almost completely efficient when on and off, but can't handle analog voltages in-between. So the signal is switching on and off at a value somewhere in the multiple KHz range, and it's period is adjusted to form a 60Hz sine wave, which approximates a sine wave. This is then smoothed with an inductor to fill in any switching gaps and make it a full sine. With massive inrush currents like your circular saw is introducing, it's overwhelming the inductor's capability to smooth the PWM signal, as the current is pulled out of the inductor before the next cycle can introduce more. Because of this, the output sees (momentarily) the raw PWM signal. The only way to "fix" this is to massively increase the size of the inductor to cope with this one-in-a-million inrush. Sensitive electronics usually use a capacitor on the input to smooth the DC ripple from their rectification anyway, which would entirely negate this "noise", but because the Kill-A-Watt (and devices like it) require interacting directly with line voltage to measure the throughput, it can't use smoothing components on the line. Incidentally, the other inverter strategies used by UPS' are "Stepped Approximation of a Sine", which uses capacitor and resistor ladders to create a very coarse sine-line signal, and the cheapest units omit the ladders and just outputs raw 60Hz square waves, letting the cabling act as an inductor to smooth the power a little.

[@mckenziekeith7434]

Some of what you are saying is not right. The inverters used for three phase motor control cannot be used on normal three phase loads. Three phase inverters for motor control do not have any inductor between the switches (IGBT or MOSFET) and the motor. They rely on the motor inductance to smooth the current waveform. The voltage output of a three-phase motor drive is the raw PWM.

[@Anaerin]

@@mckenziekeith7434 Well yes. In the case of 3-phase motor control, the inductor(s) are the motor windings.

[@WikiSnapper]

Imagine you are a battery company. You intend promotion, and instead you get some of the most thorough product testing anywhere. I can't imagine being mad about that! I would love having that kind of feed back. You can't improve what you don't know isn't working!

[@fellipec]

Fully agree, and as Matthias said, it will not affect many customers. Is a honest limitation of the product.

[@philippe888]

If this is a big company the sponsorships are probably handled by the marketing department. Technical questions like Matthias' would require the responsible ad-guy to contact another department. That is a lot of tedious e-mail communication between two people with a very different expertise. Guy probably just gave up lol

[@FerdinandFake]

The sine wave getting chopped to bits when you massively overload the inverter seems absolutely normal. Impressive the small thing even managed to start it. I suggest a brushless saw for anyone using aux power, they should have soft start circuits.

[@matthiasrandomstuff2221]

the brushless tools are all battery operated tools.

[@guytech7310]

@@matthiasrandomstuff2221 Issue is the saw is causing the ringing and voltage spikes due to inductance leakage in the motor. Its possible the motor starting capacitor is dead or out of spec. or just undersized which is making the issue worse. Try running the same test using grid power. That said the company you should be complaining about is the Kill-a-watt with horrible power supply design.

[@absurdengineering]

“Massively overload the inverter”… uh, like the entire point of an inverter is that it controls the output current, and there is no case in which it lets itself be overloaded. It will just keep the output current within limits, down to a very low voltage. If an inverter is overloaded then it’s the inverter’s problem. I’m literal here. You should be able to short the output and the inverter should keep the current to a slightly distorted sine wave, limited to the RMS current on the nameplate of the inverter long-term, and to some peak rating typically 4-10x the continuous rating for short durations like for a couple mains cycles. It’s not hard, and it works very well for starting hard loads cleanly.

[@foobarables]

The problem might not the generator but the saw itself because of how the commutation in those motors work. What you are seeing on the scope are probably resonances in the output filters of the generator. You can probably observe the same messy waveform when the saw is connected to mains. The frequencies will be different but the resonances caused by stray inductance in your house wiring will be visible. It can help to connect a capacitor directly across the motor. (they have special capacitors for those applications with three wires where one wire connects to the motor stator.)

[@jimmysyar889]

Yeah I really don’t think it’s the generator. Probably happens on mains too.

[@onurjp]

I wish he gave a comparison waveform what happens at mains. From experience I'm 90%　sure it will happen at mains voltage. That's why you don't want to plug your oscilloscope and power tool to the same mains tap.

[@kinguin7]

I'm not convinced either way right now, but I had a similar thought right when the video started. Would definitely like to see it done on mains. Which, perhaps still a fair warning about the device's limitation, but, if the same limitation applies to mains outlets then I couldn't really blame the product.

[@andrewk8636]

On mains the power has other places to dissipate. On the battery it's a closed system so it needs to be accounted for

[@foobarables]

@@onurjp You can try measuring the mains waveform. But a saw like the one shown can easily create spikes which can blow up the oscilloscope.

[@malanvogt]

This is why I enjoy your review videos. You are thorough and honest

[@85krink]

I can’t tell you how long I’ve followed you and I also can’t tell you why, but I view almost every one of your videos you put out. I dig your style and the integrity you have is almost unmatched. You are the safe for work version of AvE!

[@jsc3417]

Ok, when you measure AC voltage, it's always a good idea to NOT connect the ground from your scope to the device under test (be it neutral or ground). A safer method is to take two scope probes, connect one probe to the HOT, and another probe to the signal ground (btw, this is not necessarily earth ground and can still have the potential to kill), then use the scope built-in subtraction function to get the desired waveform.

[@alerighi]

Use a differential probe, that is even better, since otherwise you rely on the ground connection of the scope as a common return and pick up a lot of noise. Or even better: power the equipment under test via an isolation transformer, that way it's completely isolated from the signal ground.

[@jsc3417]

@@alerighi A differential probe usually costs way more than a pair of passive probes, but yes, it is the ideal probe for this type of jobs.

[@Lizlodude]

Yeah when I was learning to use an oscilloscope what I pretty much got pounded into my head is that everything will probably be ok as long as you don't screw up the grounds

[@RambozoClown]

While a differential probe is great, you can't beat using a battery powered scope when testing mains issues. It just keeps everything isolated so no worries about where signals are coming from.

[@treelineresearch3387]

Never seen using the other channel as a reference in videos/docs that cover this, good idea! Every time I've needed to do this I've just put the DUT on my isolation transformer, but it's only good for 100VA and I don't have a bigger one or a diff probe.

[@GeekDetour]

Nice video man! I’ve done a few reviews - never a sponsored video. I was approached a few times by agencies… geeeezzz, the contracts are a monstrosity 🤣

[@aserta]

Matthias, man, what a class act you are!!! This is why i trust you before i'll trust others. You've proven your worth, Sir, and it is of the highest value.

[@rafaelsakarya]

Double respect for 1) not having "should your soul" for ad money and 2) owning up to your own mistakes. Integrity, honesty, and humility are nt popular virtues these days... Thank you, Matthias.

[@TZerot0]

Great video. I really respect you interrogating your sponsors like this and holding them accountable. The reason that sponsorship have become so popular is that they work. people tend to trust the words of people that they like and well trust.

[@zwhitchcox]

Thank you for your candor in your sponsorships. I hope you find one that you feel comfortable representing…and I’m sure this video will work as a siren’s call for high integrity companies!! You’ve build a lot of trust with your viewers by standing up for the consumer. I hope it will pay off for you. Subscribed 🙂

[@shocktnc]

First video I have ever seen but this level of integrity make me want to subscribe even if I have no idea what kind of videos you make

[@Remmes]

So it's not a big deal because like you say it is common for machines like that to cause big spikes/instability but it's definitely something to be aware of. Still thankyou for being honest and even re-uploading whilst admitting your own mistake.

[@truthsRsung]

The Big Deal is the damage on the other circuits attached. The saw motor can handle the dirty power being applied. It is the EXPENSIVE b.s. that gets plugged in next to it that you have to worry about. Get those two issues strait.

[@dyllan6043]

I have never seen your videos before, but after watching this, you have gained my subscription! love to see someone willing to stand behind their word and what they believe in! keep on!

[@GregBakker]

Great discussion, a lot to think about, thanks for putting this up! I can't really imagine a more savage use case for these boxes, it's good to have some data on the ground so we can start comparing them.

[@PhillipParr]

I feel like the algorithm knows, because I just watched another video with one of these products in and was immediately recommended this video!

[@fellipec]

Matthias is a guy that puts value on his integrity. Ecoflow should feel honored to, even with a minor flaw that he notice, still doesn't bash it, and is honest about how it would only affect costumers in a few corner cases. No product is perfect and I think it is still a good battery, and being aware of this limitation, IMHO, doesn't affect the product reputation.

[@REALBanannaman]

HF vs LF inverter....

[@JoshuaRosaaen]

This kind of thing is very rare on KZbin I think when it comes to product sponsers. Thank you for the insight and integrity. Got my subscription. Looking forward to seeing more.

[@NoNonsenseKnowHow]

Thanks for this PSA! I have one of their power stations and great information to know! So don't plug sensitive electronics in while using power tools at the same time. Good stuff. I didn't watch through till the end to see if you mentioned it, but I would imagine most portable power stations like this probably have the same issue

[@svdleer]

Good that you explain on the end of the video what actually was the case, and what is the real issue, and that it often occurs with such high power tools.

[@jaapweel1]

Now I’m curious if more well known brands of battery boxes (Jackery? Anker?) have this problem.

[@apdj94]

I love this. Ecoflow had no idea they were sending their products to someone who actually understands electronics. Maybe their marketing team learned a thing or two about what they are trying to sell.

[@stoojinator]

I'd say they sent it to him because he did understand electronics. There's no reason that they'd send it to a woodworker. But my guess is they were hoping he'd endorse it without question.

[@FFVoyager]

@@stoojinator I've seen woodworkers in the UK being sent them (and using them) - @Badgerworkshop for instance. I've wondered why they are sending these things out in quite such large numbers around the world - I guess they simply want people to see the content and connect Ecoflow with mobile power supplies.

[@rpnp2]

@@FFVoyager They send them out because it's a very effective and cheap way to market directly to a target audience.

[@ArkanoidZero]

If you weren't a regular viewer, it's very possible to not know that Matthias is a trained and working Electrical Engineer, not a full time KZbinr. I don't think a marketing department would feel comfortable sending a product like this to ElecroBoom or Dave Jones of the EEVBlog, not that I think they would take it.

[@VeluBeru]

@@ArkanoidZero Check out EEVblog 1499, although whether he was sponsored is up to interpretation, as neither his forum post or the video itself provides an answer to that. Perhaps it was a bit of independent investigation on his part.

[@loc4725]

Sir you are a very rare thing to find these days, a man of integrity. My hat off to you.

[@plasticbmw]

This guy is great...subscribed back when I was into woodworking and I still stay subscribed for stuff like this

[@BoWhitten]

I respect your honesty and desire to do the right thing. You are a good person. Thanks for the clarity.

[@MrGatlin98]

Wow the turnaround time between the two videos was very fast. I just watched the first one this morning, and here's a new revision in just a couple hours.

[@matthiasrandomstuff2221]

I hurried. If I just took the old one down, people would have all kinds of theories!

[@MrGatlin98]

@@matthiasrandomstuff2221 good point!

[@BenHuttash]

So much of this video is over my head but it’s good to know about. Commented and liked for the algorithm.

[@Guywithcrazyideas]

I love honest smart kind people like this guy.

[@rickpalechuk4411]

You (and others) need to do more videos like this and hold the boardrooms accountable for the money making products they peddle. Thanks for sharing. Cheers

[@Friddle]

Funny timing with the revised version, something like half an hour ago I watched the old version

[@matthiasrandomstuff2221]

You must have still had the link. I unlisted it more a few hours ago.

[@Minionz]

@@matthiasrandomstuff2221 Probably added it to watch later from the feed like I did earlier, before it was unlisted and just now got to the video.

[@Friddle]

@@matthiasrandomstuff2221 that makes sense, i opened a bunch of videos open in different tabs and came back to watch them all

[@CraigsWorkshop]

If all sponsorship arrangements were approached with this kind of honesty, we would all be a lot better off. Good on you for sticking to your principles Matthias. 👍

[@jackle3002]

Good on you for having a backbone! You’re one of the good ones!

[@jamesw5584]

Its normal in my opinion, the same issues occur on most switching power supplies when faced with an inductive load that will try to pull all the current in the universe for a split second. I think you're expecting too much if you expect to not see any change in the sine wave during initial power up. Maybe if you had some iron, like a big 110v to 110v transformer and a nice capacitor you could mitigate it somewhat.

[@mernok2001]

He needs a 120 V isolation transformer. 110 V is a VERY old standard and doesnt exist in Canada.

[@akardasis]

Wouldn’t it be great if product makers communicated with their customers like this. I would feel so much better about buying something with some transparency into the testing processes.

[@RinoaL]

I'm unsure how one would design an inverter to make the waveform perfect during motor startup.

[@AndrewBlack343]

It never going to be "perfect" but Oversize the inverters and add inductance. It would drive up the cost and size of the box and becomes uncompetitive.

[@damnperrys1]

Thank you Sir! Always a pleasure to enjoy your time and experiences!

[@twobunnyrabbit]

Respect for you for your honest review.

[@thejo6331]

yeah, high-inductive loads will be hard on any inverter-based supply controlled with semiconductors. The instantaneous demand they create is really outside the scope of normal loads. That being said, that can be considered a conducted emission, and (IMO) UL should consider testing for this. These huge battery banks have a real potential use case as jobsite power for construction projects without their own supply, so it's definitely relevant info.

[@geoffrjjjjjjj]

Your integrity is impressive! I'm in awe.

[@squarrl]

I appreciate this. There are also lots of devices being sold these days on online sales platforms that are 100% dangerous and no one seems to care.

[@dw7444]

Yep, that's pretty typical for high frequency inverters... best to keep large inductive loads on low frequency inverters if you can.

[@vladimirfox5750]

Massive respect for being honest and having integrity.

[@explosify5035]

4:37 the setup they show is a simple full bridge rectifier circuit with a capacitor to filter out the high frequency stuff, and a zener diode to cut off the voltage. I dont know about with higher wattage stuff, but when I was looking into making my own rectifier, but zener diode regulators were frowned upon. along with that, they are super noisy under load. but that is only the charging circuit, so it was probably some response about how the breaker flipped when you plugged it in and not the AC generation stuff.

[@miklov]

Fascinating. I have not watched any of your other videos as far as I know but I suspect I will want to do that in the future so I subscribed. It is probably hard to get an inverter to be nice under those circumstances, in the grid there are so many other loads that helps in sinking the noise. One could add some filtering but that would likely include lots of copper and increase both the price and weight of the device. Anyway, I enjoyed your very earnest way of dealing with this matter and your priorities in selecting a sponsor. It is sad and common to see sellouts so this video made me quite happy. Thank you!

[@nico.m8346]

thank you for your honesty and intelligence

[@AndyBlackman]

Integrity. What is more interesting is the company in question did not challenge your results or have someone review your process to ensure they could replicate your results. Or if they were aware at least compare results; at least I didn't get the impression they did. It is still an interesting issue to be aware of.

[@matthiasrandomstuff2221]

They said "this is normal", which suggests they were aware of the issue.

[@jspencerg]

@@matthiasrandomstuff2221 I know enough to understand the issues and what happened. I agree with other poster in that Ecoflow should have problem solved with you rather than cutting you loose. I will not post to YT unless I'm an expert about content. That precludes all posts about electronics!

[@Flowing23]

Very interesting. Thank you for being so honest as to come back and correct the mistake you discovered. It will be interesting to see if Ecoflow will now follow up with you. It was very worrying that they stopped contacting you, it's OK if there was a difference between you and Ecoflow on the severity of the issue you diagnosed. They should not have broke off contact with you, that is a worrying sign about the companies approach to problem solving/customer care. Regarding the other unnamed company that reached out to you to do a review of a solar power generator, you should let us know who they are. I am now more interested in seeing a review of their product than ever, because you do a thorough critical review should not be a reason for them not to follow through with to review there product.

[@sirgermaine]

I was surprised this video wasn't sponsored by established titles like every other video I have seen this week.

[@MSI2k]

Matthias is so rigorous with his methodology. It's great! Keep doing what you do, bud.

[@wgm-en2gx]

I appreciate your honesty and fairness. One question though: what happens to the waveforms when the saw is on normal line power without the battery box? Is it possible that the oscillations are due to the sudden high inductive load?

[@ferdis7]

Your relentless pursuit for integrity is always refreshing :)

[@LarsSveen]

Thanks for your honest work. They apparently don't realize that it's not about how big of a deal the issue is, but about being honest and clear about your product.

[@matt7403]

Thanks for your double integrity. Even if the saw is drawing out of spec, surely the least the company can do is modify their design so that even if they don’t clamp the excess voltage, it fails gracefully. Just because other inverters also failed to fix the problem doesn’t make it OK. I’d also be curious what the startup waveform looks like on a wall outlet.

[@trudyandgeorge]

I'm curious about that too

[@guytech7310]

Its the circular saw that is generating the voltage spikes & ringing from inductor leakage from the motor. Really the issue is with cheap electronics that don't include any transient voltage protection. Its like blaming the car manufacture because you didn't use your seat belt during an accident.

[@allan.moeslund]

A low-pass filter on the output cable made with a ferrite core would likely solve the problem. Simple, cheap and effective.

[@martinbruckner2109]

I had to do a little bit with power supply design in the past. Most probably a simple solution is not possible. A simple passive filter would most probably be large but still not very effective. And it might be neccessary to redirect the high frequency energy into some resistor via a capacitor or it could lead to even higher oscillations on the input side which could even kill the power supply. The only clean solution here would probably be to choose a much stronger power supply that can easily cope with the high start up current of the circular saw. Or alternatively use a saw that has a built in soft start feature.

[@oezzimix]

I didn't understand much of this video, but thanks for you transparency!

[@shenkerism]

Once again, the engineers at companies that might work a sponsorship with you should be quite pleased.

[@EscapismPinball]

Always better to be pissed off than pissed on.

[@Bill_CBR]

Matthias, I guess they didn't realize you were an actual engineer. Their loss. I guess that's the price you pay for honesty and integrity. Excellent video by the way.

[@Reiikz]

Integrity, instant sub to ya. This is also very useful information as I would like to do solar one day. Useful to know I should not hook up motors and electronics in the same circuit. Although that's generally good advice for mains circuits too.

[@bread-gz3rl]

"Peddling mattresses" I've never heard anything more true about YT sponsors

[@teedawg2112]

I'm happy never see another ecoflow sponsored video on YT again - nothing against you Matthias they just flooded the platform

[@Nitecrow314]

Absolutely! Not just ecoflow. Brands trying to get on the "owning this makes you a worthwhile person" bandwagon. Fine for the brainwashed, but no thanks.

[@dustysparks]

The latest one I've seen is the "Become a lord or lady by claiming 1sqft of Scotland"... they're EVERYWHERE!

[@ruben_balea]

@@dustysparks Established Titles? It smells like a scam, I mean I doubt they are actually planting trees and/or making any kind of charitable donation. Of course the title itself is fake but I guess people buy it thinking they're helping to reforest Scotland, because if they really think they are buying a piece of land and becoming members of the nobility then they should go back to school or maybe even see a psychiatrist.

[@ssoffshore5111]

It's not often YT'ers have enough integrity to call out a sponsor when they see a potential flaw in their product(s). Thank you very much for sharing all your findings, you just gained a lot of respect from at least one viewer! 😎

[@dandesjardins937]

May not be a lack of Integrity as much as a lack of knowledge. You see many YT channels hawking products that clearly are not in their area of knowledge. Maybe they don't understand the issues at his level.

[@JustinBellingerTV]

It's rare to see someone admit to their own part in an error (even if it is only a partial error, because the problem is still there, even if not as drastic or as big as originally reported). For that alone you get a follow, because, in the world of KZbin, trust is sacred. Thanks for sharing.

[@flowerpt]

I have a Tripp Lite power conditioner unit that I put inline between electronics and a sketchy power source when using one is necessary. The efficiency is only 80% so that's a big downside for a battery or generator fuel. I do appreciate the head's up about inrush vs. electronics on the same source. That never crossed my mind.

[@fablearchitect7645]

50 amp rms inrush current at 120V rms is 3000 watts. Would oversizing your ecoflow system to facilitate this inrush power mitigate the problem? Also is the OCP on the ecoflow not tripping the 50 amp inrush because its relay curve response time is too slow?

[@mato9282]

I love that you gave that company the benefit of the doubt by saying they “ gave this power supply to some random KZbinr.” And not like “a major player and former EE at RIM.” Even as a non-engineer myself I know who I’ve been watching for the last many years. Never doubted your integrity!

[@andymarteney9820]

you just gained a subscriber. Awesome explanations and honesty. Great job

[@trakeC]

Idk if I am going to watch anymore of this guy's videos but I subbed and commented for the integrity

[@FortuneZer0]

You pissed off a sponsor again?

[@matthiasrandomstuff2221]

ha ha

[@wmlye1]

@@matthiasrandomstuff2221 it could be worse - you could have dropped it off of a scaffold...

[@WillProwse]

This is not integrity, it's ignorance. Of course this will happen with an HF inverter. What you need is a high quality LF inverter that can handle power tools. I'm surprised that little hf inverter circuit even powered that saw! That's insane. And I have shown how to actually break these units and some of the ground neutral bonding issues present when using the double voltage hub. But putting a massive inductive load on such a small hf circuit is going to cause this issue regardless of who the manufacturer is. Use a nice victron with a surge capacity design for your application and you won't have an issue. I try to critique these products and break them on my channel every single day, but this "critique" just shows a lack of understanding of these circuits. Trying to filter that massive surge is just unrealistic. Try an LF inverter instead. And one large enough for the inductive load you wish to power.

[@namibjDerEchte]

Why wouldn't it just brown out like a normal supply when faced with startup current?

[@deBug67]

Thank you for the heads up! I just got one of these so I will make sure to avoid using power tools on it while also powering electronics.

[@NoelBarlau]

And this is why we subscribe. You can't be bought, and that is a rare thing nowadays. I also felt vaguely sticky just putting a clearly labeled sponsored link in the description to the products I was using in my videos - mostly just to see how this KZbin thing is supposed to make money for the content creators. It's a strange new world that I'm still personally not comfortable within. Anyhow, kudos on the integrity, and thank you.

[@evunotry-force2073]

very nice you are the first KZbinr i have seen that has done this proper due diligence

[@ndmusick11]

That would require quite the inductor and capacitor on the output of the inverter to clean up the signal in that kind of current draw.

[@duanebeyer950]

Repeating what has been said, but we need more folks who stand up for what is right. THANK YOU. I would think in a small shop that has a CNC or LASER, this could be an issue. Glad you pointed it out.

[@xsasx]

I am looking to invest in some of this. Saw this and you for the first time. Subscribed just because of your integrity. Thank you.