Correction To The Sun Fun Kits Cell Test Video. I Forgot Something Important.

In this video I describe a mistake I made on the previous video where I tested cells from Sun Fun Kits. The state of charge that I reported them to have when I received them is not correct. This doesn't affect the capacity or the swelling I experienced with these cells but it does affect the discussion of balancing. I will put a link to this video in the description of that video. I apologize for the mistake. Here is a link to that previous video. • Let's TEST "Certified ...

[@peterrock2838]

Integrity is all but gone today, so it is refreshing to hear your retraction. I like your channel because I sensed your honesty from the start. I predict the pre-charge of those two cells will have no effect on the test results, but we shall see! Thank you for your videos.

[@rv10flyer84]

We all mess up. Having integrity enough to admit that is very scarce nowadays. Great job. It's no different in relationships.

[@dougyoes]

Thanks Ray. We all make mistakes. We just hope they don’t cause harm to others - or to ourselves. I chopped up my hand in my table saw one evening. It was a dumb, dumb move. I knew better. I had made thousands and thousands of cuts on that saw. But it was late in the evening. I had been working hard all day, finalizing some kitchen cabinets. My wife told me, “Honey, you need to quit.” I replied in an angry tone, “I have a crew coming tomorrow to deliver the granite! I have to get this done.” I cut a thin piece and used my push-stick. But then I immediately reached across the saw to grab the piece.” It caught on the back of the saw blade and slammed my hand down. A few minutes later I was in a helicopter headed for the hospital. A week later I resigned from work (took an early retirement). I had been working from home as a programmer. But typing on a keyboard was out of the question now. That one mistake happened literally in a fraction of a second. And it impacted the rest of my life.

[@RayBuildsCoolStuff]

WOW my friend. I too had an altercation with a tablesaw when I was much younger. They put the finger back on but you might notice that I often hold it up out of the way when doing intricate tasks that require dexterity. I'm sorry that your outcome was so significant but I hope it led to something even better.

[@machielhoogenes3158]

Wel spoken ray, i totally agree with you. Its just about taking responsibility for youre actions and choices. This is something what is getting rare these days.

[@matthewellisor5835]

Integrity: Doing the right thing even if no one would ever know.

[@matthewknight5641]

I'm kinda addicted to learning about this solar stuff and working my tail off trying to get it all together. It's really cool of you to share your knowledge. Thanks for the videos and God bless

[@jamesbsa6450]

Such an admirable man. Thank you for your example of integrity.

[@brianevans4525]

U are a good man ray wish more people was just like you in the world because this day in it's very hard to find trust worthy people. And that's the reason why I can count my true friends on one hand. I'm just like you very honest and loyal to anyone in my life have a great day from Brian in my camper van in Las Cruces NM.

[@GregFurtman]

Ray, you are an honest & good soul. It is great to see that integrity is not dead! Keep it up & maybe you'll rub off on others. :)

[@mfgxl]

Besides learning that you are a great guy, I learned that we are all human and that mistakes are a part of life. Also makes me feel good that a guy about the same age as you doesn't have the same brain we had when we were younger, but the tradeoff is wisdom.

[@gumpster6]

Thanks for your honesty. The people who don't make mistakes are the ones who do nothing. Looking forward to the retesting results.

[@tassieflash63]

Thank you Ray, your humility to life's problems is so refreshing and seldom seen.

[@rickbattle5706]

We can't be perfect, but we can be honest. Dead on. No worries. Retest the batteries and carry on.

[@101markharris]

Thanks Ray , Ive just discoverd your site a month ago ,now your the goto guy, many thanks for your uploads.

[@mikedurham4448]

now thats what i am talking about .. !! .. smiles .. shit always happens .. it is what u do about it is what matters ... proud of u

[@davidroberts6790]

Thank you very much for this video. I would really like to hear about the building science symposium you are attending if you have the time and motivation.

[@johnhill3507]

Great video my friend THANKS for reminding me about my integrity.... have a great trip.

[@dennydenny4966]

You got one subscriber more ,thank you for your honesty

[@cuisinartOH1]

Two

[@JonAndKatyAnderson]

This is great! I think you have been scratching the surface of what makes good character in all your videos. I would love to hear more stories and lessons if you have any. I'm an engineer, and I've had moments where I've screwed something up, and I feel it's in those moments where I have the greatest opportunity to live up to my idealized self, and it's often hard. But it is extremely important from an ethical standpoint in the engineering field, because big things can be at stake sometimes. As I've shown more integrity, I've been trusted with more, because if one can be trusted with little, one can be trusted with much. Character is far more valuable than technical skill or intelligence or knowledge. Character sets the direction, and intelligence or skill level sets the intensity / expanse of impact in society. A smart person of low character will cause the greatest pain to mankind.

[@hendersonsobers396]

Love your integrity Ray. I give you 11 out of 10 points for that.

[@BenMitro]

Thanks for clarifying that Ray.

[@keithbrookshire]

Thanks for the follow up Ray.

[@jeremysongs6135]

Hi Ray from Brasil, I admire your integrity thanks for all you do.

[@ramonf5179]

Thanks Ray. Very good information

[@Kyee71]

Just an outstanding video, I see great things for this channel.

[@jw3843]

I agree. There is no reason not to admit you made a mistake. It happens. I worked in the A/c business and i owned up to any mistakes i made. biggest one I made was when putting a unit back together, i put the wrong screw, it was too long, in a screw hole that pierced the evaporator coil end tube and created a leak. I started pumping the system down and told the customer and my office about it. took the next 2 or 3 hours to fix it at no cost to the customer. But it got fixed and did not cost the customer anything. I also like to be told when i make a mistake so i don't do it again. If you keep doing it after being told about it, then it is just laziness and not caring about what kind of work you do.

[@klassichd10]

Great thanks an Kudos! Integrity is fundamental - not only in building industry.

[@energydreamer5347]

…… just about a genuine as you can get young man; N O W A I T……. ……. it is as genuine as you can get - thanks Ray and keep them coming! Our society has nearly gotten to a point where this level character is found no more, it’s shrugged from the shoulder as not necessary or needed or required but it’s a huge reason why you have me as a fan and a subscriber. Wanted to take time to thank you for this quality. Interested in hearing about your Builders Science meeting/conference too !!! God Bless! mj

[@randylenart9674]

Yup dont dwell on it Ray everything seems like a big problem but in the end everything is just a small problem

[@tastiger91]

That's good values to have. So many people run away or not admit mistakes. The pain is usually shorter to acknowledge, try to fix and learn.

[@FutureSystem738]

Thanks Ray. To err is human. Those who never ever make mistakes are…. Liars. Thanks for your honesty and integrity! Cheers from Oz 🇦🇺 Looking forward to the next video.

[@beertje5885]

Ray, You are the best!!!

[@davepartlow6430]

Well done Ray. 🤙

[@AmjadKhagga]

You are an honest and a great person, after all we are humans and not angels, thus it is quite normal for us to make mistake but great are those who confess their mistakes

[@tanethomas]

Very honest. Thank you!

[@rv10flyer84]

I found a 4500 sq ft house out of level 5" while starting up the HVAC. The house was 99% complete. I knew from standing in front of the house that something didn't look right. I had some experience building a home and two shops of my own from the ground up and around construction my whole life. I did a little measuring and found that the concrete basement was poured out of level. The original homeowners have moved on after 15 yrs. They never knew, because that would have been an expensive fix and would have just upset them as everything had to be just perfect. Nobody complained during construction, but I know the framers, siding, sheetrock, cabinet contractors had to know too.

[@brian_abroad]

“If you’re not part of the solution, you’re part of the problem” - Joe Henderson

[@en2oh]

Great story… for me, the take away message is “no short cuts in testing.” We learn from our mistakes, but in science and engineering, we follow protocols for a reason. If you stick with a protocol, you will always compare apples to apples. Thanks for sharing this

[@creamshop]

It takes a mature man to admit mistakes, we all do make em but rare are able to man up

[@overthetopcargotrailerjerr2278]

Ray YOUR A MAN OF PURE INTEGRITY....that feses up to his mistake.. MY VOTE Ray for President in 2024 🤠🤠

[@markstipulkoski1389]

Please leave politics out of this channel. Some of us come to channels like this one to get away from politics.✌️

[@overthetopcargotrailerjerr2278]

@@markstipulkoski1389 your right 👍

[@georgef7754]

You are an honest man. Your "mistake" made no difference to the end result.

[@yooper423]

Thanks Ray! Love your integrity...but, from watching your videos from the beginning, I already knew you would never knowingly mislead us.

[@user-ej7tn7el6v]

I liked your attitude.

[@pawnslinger1]

In my profession, we had two sayings: (1) You must learn from your mistakes, so never be afraid of them, and (2) If you don't make mistakes, you don't do very much... I believe both of those things, yet most of the people I know, outside the profession, are afraid to make mistakes and are afraid to admit mistakes. I am a retired IT professional. An old project leader. I remember my mistakes more than I remember the projects I worked on....

[@Woodyjims-shack]

I've been wrong so many times man. Well done👍

[@budmartin3344]

Bottom line, the capacity test results are still not as claimed by SFK.

[@eduardoperez891]

My respect.

[@KD0CAC]

Last video - I forgot to ask , defining " automotive grade " ? Thanks again

[@matthewknight5641]

Also cool you admit your mistakes... takes a good dude to do that especially on youtube

[@SkypowerwithKarl]

My main trade is a machinist. Imagine working on a part that has a weeks worth of multiple machining ops and heat treatments and you screw up. There’s no repair allowed, there’s no fix. It’s called scrap. The more you look at it the more it eats you. I hate loosing, it’s rare but it happens. The only thing to do is to inform of the screw up, order more material and ready yourself to start over being sure not to fall into another rabbit hole. Could I have let it go? probably, would inspection have caught it? Due to the complexity probably not. Would it have caused a problem with functionality ? Not without modifying the mating part and pissing off the costumers some time later. Would it have been traced back to me. 50/50. Still have to do the right thing. It sucks but that’s integrity.

[@edwardbyrd7667]

DOH!!! Stuff happens, I’m gettin older too. 😀. Like you say, the cells still fail capacity, it is good to know they aren’t shipping 75% SOC cells, but that wasn’t the primary issue now was it. Certified Automotive Grade my unairconitioned chicken’s aunt

[@CncObsession]

Just subbed yesterday because of the battery video. I thought it was very well presented regardless, hence my sub. Then an integrity video and done in my State. Does it get any better? Thanks for sharing some of life's lessons.

[@roshawnsims8390]

I just watched a video class from work and it stays you can't learn unless you make mistakes

[@mrsmithdaddy]

The good news is it's never too late to say "I'm sorry, I was mistaken." Thanks for teaching us on multiple levels, Ray. The bad news is we still don't have enough trustworthy options for sourcing top quality cells. I'm sorry I didn't get to meet you at summer camp. I didn't go this year. I was having too much fun on the electric sailboat you and Jenny Wu helped me build. ;)

[@RayBuildsCoolStuff]

Wait! Say what? Give me a clue about who you are. Tell me about this sailboat.

[@mrsmithdaddy]

@@RayBuildsCoolStuff I emailed you early this year after recognizing your summer camp t-shirt on an older video. I bought a 28' sailboat last year that had a rusted out inboard engine. I pulled it out and replaced it with an electric motor kit. I built a 48v 280ah battery to store enough energy for the day sailing and light coastal cruising that we wanted to do. It was a lot of fun, and everything worked out pretty well this summer. We're up here north of Boston, so the boat's out of the water now. I'm contemplating a 2nd battery build before next season to extend our range a bit and give us more margin for the unexpected.

[@rikehm3735]

When are we going to get video's on building science? Thanks for sharing, cause makes it easier to try new things.

[@RayBuildsCoolStuff]

I’m getting my chores caught up.

[@SiriusSolar]

If you still have the original video posted I think you can put text over the video after the fact that States the correction.

[@houseofancients]

hiya ray, integrety rocks.. still does not change the discharging results... and they failed that horribly

[@VideoByPatrick]

I think this update should be noted during the first review video.

[@RayBuildsCoolStuff]

There is a bold starred comment in the first line of the description of that video that requests that viewers follow a supplied link to the correction video. I don't edit any of the videos so the description is the only place I can make notes about corrections.

[@Dutch_off_grid_homesteading]

Heya, oke it's nice of you to edmit to a mistake we are all human still the capacitie test aren't good

[@TheFlybyman]

🙏💪🏽👌👌👌👌

[@AmjadKhagga]

The best way of balancing the cells of a battery is avoiding the use of an active balancer, because active balancing can never be as efficient as is the passive balancing method and the best way of doing passive balancing is first measuring the amp hour capacity of each and every cell and then arranging the cells in groups of equivalent amp hour capacity while those groups of equalized amp hour capacity (by making a justified combination of weak and strong cells connected in parallel, hence when we use such group of cell (connected in parallel) we need no active balancer because the cells automatically balance each other

[@CollinBaillie]

Until you use them.

[@vtorsi610]

So the Ah capacity may or may not still be low? But now we will neverknow if the initial state of charge was similar or not. Can changing the Charging procedure affect the discharge capac by 5 - 10Ah? Would be best to verify if changing your charging procedure does or does not affect the discharge capacity.

[@junkerzn7312]

I've been meaning to also add a caution on your use of bench supplies to charge these large batteries. A purpose-built battery charger can handle large reverse voltages (e.g. charger is turned off and at 0V but still connected to a battery or battery pack at X volts).... both while charging, discharging, on, off, or if the mains are lost while it is connected up. A bench supply, however, is virtually guaranteed to NOT have a wire-or output and will be damaged or something will burn up under similar conditions. So you need to be careful when using bench supplies that aren't battery chargers to charge these large batteries up. What I usually do is put a Schottky power diode in series with the output of the bench supply as a safety. These can be found cheaply anywhere, but are limited to around 5A without a heat sink (free air heat dissipation). The voltage drop is typically around 0.3V but varies a bit with current. So in this configuration one has to use a volt meter under load (like a 15W 30 ohm resistor) to dial in the exact desired voltage since the display on a cheap bench supply (a) doesn't take into account the diode drop and (b) is probably off by +/-0.1V just generally. So using a volt meter to dial in the correct voltage is mandatory when using bench supplies to e.g. balance cells. In anycase, its something I noticed in your earlier videos that is a bit dangerous. There are multiple potential issues with bench supplies connected directly to batteries. A linear supply usually has a power transistor and those often have very low reverse break-down voltages (12V or less is common). Supplies that use MOSFETs have a reverse diode built into the MOSFET and will conduct backwards if the voltage on the output is higher than the voltage the supply is trying to push. A synchronous supply makes assumptions on the direction of current flow and will melt. A switching supply has other components that will conduct the wrong way. Many supplies have bleeder resistors or relays that shunt the output to ground when turned off. The list of potential problems when the supply is directly connected to a battery (i.e. is not the only source of voltage) goes on forever. At best the supply will be damaged or blow a fuse, at worse the safeties will fail and it will catch on fire. Dedicated battery chargers and testers, on the other-hand, are designed to handle all of these conditions. On, off, mains lost, still connected to (e.g.) a 48V battery pack when turned off, and so on. I use bench supplies to charge large batteries myself, but I always throw in a Schottky diode which more or less works around these issues. Its important not only for the health of the bench supplies, but also for safety. One diode per bench supply, located as close to the battery as possible. So if using three bench supplies in parallel, each one needs a diode. That not only protects the supplies from each other and from the battery, but it also allows any of the supply inputs to go to ground without shorting the battery or other supplies out.

[@rv10flyer84]

Fortunately my 20,640 w PV, two 12K's are more reliable than the grid we used to have. I run a 50 amp, 30 amp, 20 amp power supply to top balance my batteries.

[@JLTPhotog]

✌️

[@travishodges5179]

Lmao, 420 math never adds up!

[@hommerdalor6301]

😅 Only people who do nothing don’t make mistakes. Nice to admit.

[@mattg8787]

#RayBuildsCoolStuff question dose this video change how sun and fun kits treated you . with the E mail .? the order that i seen the videos was i seen the build video then the video with the Emails from son and fun kits thin this one.

[@RayBuildsCoolStuff]

No, I made this video hours after the test video. This mistake had no effect on the capacity test or the swollen cells. It only affected the state of charge at the time I received the cells. SFK was upset because their cells didn’t meet their claims and they had never tested them so it came as a complete surprise. I don’t think any other KZbinrs had actually tested their cells. I didn’t expect them to do so poorly. Their later response was just an emotional lack of judgement.

[@longdistancerider691]

[@yasasjayasuriya1258]

@Ray Builds Cool Stuff I respect your honesty and I admire your quality of taking responsibility for mistake you made. These days, it's really difficult to find people like you. This is the one of reason I would like to watch your videos. (because I know, I'm always getting right information/knowledge). Currently I'm building home solar system, so I would like to get every bit of detail which will help me to build this system. Today I watch one of video from sunfun kits: kzbin.info/www/bejne/jqWkloCJg9qYfKM I think they made this video as a reply for your finding. Here they mention capacity unit Ah not accurate and we'll need to consider Wh. Also they claim some energy waste due to temp rise when testing on EBC-40A tester. But they missed that you test both sunfun kits cells and other merchant cells on same environment. So we don't need to consider on EBC-40A efficiency. Anyway, can you explain/ give comment on this Ah, Wh thing? bcz I don't see any point on that matter

[@RayBuildsCoolStuff]

I and others have found the EBC-A40L to be consistent and accurate. He didn't attack the accuracy of the tester until he used it on cells at his warehouse and didn't get them to test to rated capacity and far below his claimed capacity. The manufacturer puts a Wh rating on the QR code. They all say the same thing as they are based on the class and size of the cell. They then test in Ah and publish this result for the individual cells. The real problem with the tester we use and by we I mean most of the youtube and diy community, is that it only tests at .14 C which gives a higher result than the .5 C rate that the manufacturer uses. Bottom line is we, all of us, are in the dark about what the manufacturer is doing with their cells and how they are handled after they leave the factory. The ratings are established by the resellers which is by it's nature, marketing driven. The best we can do is find a trustworthy source by testing the cells we get from different suppliers in a consistent manner. Then we hope we can get a consistent and reliable product for a price that makes our batteries economically viable. Then we hope that supply doesn't change next month or next year. Our best resource always seems to be the individual people we work with. Best of luck on your project.

[@RD-qn4gt]

Being in Architecture, I have seen a Site survey company make a mistake on the site plat, builder built his house based on the site survey and everything. Neighbor came over and said, hey your house is on my property...lol, not really funny, but.... He had to tear it all down. So your mistake is nothing like this. I make them everyday it seems. Just made one this morning on 3 buildings going out with 127 sheets printed!!!!Geez! I could kick my self!

[@RayBuildsCoolStuff]

I feel your pain.

[@typxxilps]

80 Ah of difference is a lot but the capacity test is not impacted and that is what counts. And of cause ambient temperature. And I hope to see this build been built soon even though I do not really like these cause they are abused to sell not the best cells with these cause these kits usually do get to the less experienced that do not check the capacity. Wondering how poor they had been prepared the cells they had shipped to you.

[@rocktech7144]

Look man in order to transport these cells legally a 30% charge is all that should be in them. The important concideration is do they contain their rated capacity? If not they are used cells that are being reused for battery kits. You should top balance and assemble then cycle a couple of times THAN see what the packs capacity is and verify that the balancer works. I'm betting they are reused cells.

[@argi0505]

Can you please give me jenny wu's link? Anyone? I can't find anywhere

[@RayBuildsCoolStuff]

[e-mail]

[@argi0505]

Thank you Very much my friend!

[@coleman6131]

Editing is something you should _definitely_ be doing to your videos!!!

[@jaimei.jimenez1382]

I am not sure about honesty at work. After 37.5 years working in the payment industry. I have always been honest and have always recognized a mistake of mine in the first place, before anyone would have noticed. My peers who tried to hide their mistakes have not had a very different career path than mine because of it. 🙅

[@sfkenergy]

Here is our reply; kzbin.info/www/bejne/jqWkloCJg9qYfKM We have tested our cells they all test above 281 AH we tested 3 cells and the highest tested to 285 AH. We have posted links to our ZKE curve data as well as pictures of our curve data. your testing process is flawed as you have not tested grade A cells before, the correct way to determine capacity is to take measured watt-hours and divide by nominal voltage. Grade A cells have a 3.25v under load, however, your docan cells are lower usually 3.2V because of this both cells still only make 900 Energy (watt-hours) but the grade A will only need 276AH to provide this vs the grade B requires 281.

[@RayBuildsCoolStuff]

All testing of cells should be done under the same protocols. I always test at 40 amps and use the constant current discharge test. I understand that you used a 30 amp constant pressure discharge test. You state that you believe the 10awg wires of the tester are rated for 30 amps but they are silicone insulated wires which are rated to 75 amps. This is the same reason you can get away with the pair of 6awg wires in your battery kit with a 200amp BMS. 6awg wire is rated for 50amps that would be inadequate however your wires are also silicone insulated making the pair adequate for approximately 235 amps. The heat generated in the 10awg wires is not relevant because the sensing wires of the tester reads and controls the the load on these wires and the heat generated becomes part of the continuously monitored load. I will continue to test all cells with the same protocols for fair comparison. Good day.

[@upnorthandpersonal]

@@RayBuildsCoolStuff He writes "but the grade A will only need 276AH to provide this vs the grade B requires 281." - that's nonsense. It's one the only reason the Amp-Hour is what you use to measure the capacity of a battery: it takes voltage and losses out of the equation. I've got a video on my channel that shows this in an extreme condition. A 280Ah cell is supposed to be able to deliver 40A for 7 hours, with 2.5V being the cut-off cell voltage - that's all there is to it.

[@RayBuildsCoolStuff]

@@upnorthandpersonal hi up north! I didn’t know you had a channel. I can’t wait to get home and check it out.

[@upnorthandpersonal]

@@RayBuildsCoolStuff Don't expect too much - my last video was 7 months ago. There are two videos on batteries: one is the aforementioned video on a capacity test, the other on charging LiFePO4 in cold temperatures. The rest is completely not related to batteries...

[@CollinBaillie]

Just run the tests entirely on the ZKE tester Ray, and post the graphs. We'll see the voltage, the Ah and wH figures. Use the proper 4-wire method and you can be sure the test is accurate. If you post the csv files, all the better for anyone to download and graph and analyse themselves.