Clark, I've been following for a few years now and I have to say your channel is by far the most practical and informative. You have saved me thousands . . . keep up the good work, it is really appreciated.

I use to design these. I used one to run an altitude meter that ran on 24v on an airplane that only had 12v. A lot of large computers use point of load converters to avoid voltage drops on low voltage lines.

Clark Always a pleasure seeing your videos! Fair winds and thank you!

Since seeing Emily I know you are a genius 😮

Thank You! The number of applications for both Buck and Boost for me is off the charts! I didn't know it could be that easy. Really appreciate the link and I purchased one!

him: this is my handy dandy battery pack I built years ago TSA: no, sir, your gonna have to drop your pants.

In your final version, I would recommend creating a "plug-in" model. One end that plugs into he house 24V, and the other end that plus into the laptop. I would enclose the variable voltage converter with a case (so you do not lose any smoke that might contained in it) -- just think of it as your power brick for your laptop. Effectively that is what it is. I use this very system in my off grid setup to charge my 18V and 40V power tool batteries. Love the channel.

You can DIY but there are also very inexpensive universal 12V laptop chargers with a car plug. Alternatively most new laptops can be charged through the USB C port and even if you don't have a 12V car socket, you most certainly have a USB socket.

Well cool, super training video! Thanks so much

I didn't realize they made buck converters that big. My only experience with them was when I built an enclosure for my 3D printer. I have a 12V AC/DC power supply to power the arduino nano, exhaust fan, and LED strips, and used a small buck step-down converter to provide 5V to things like the temperature and humidity sensor, control knob, etc.

Yes, please. More on the dinghy video bilge pump. Might need it for the dinghy's fishfinder :) Thanks, so much.

GREAT video. Thank you.

Clark your amazing, always love how informative your videos are.

This is perfect. It is so crazy to covert power for the many portable devices that we all have.

These sorts of switching supplies are a bit problematic for three reasons. First, these adjustable switching power supplies on amazon are mostly bare boards and touching the board in the wrong place while it is operating can mess up the switching power supply's feedback resistors (which are usually well over 100Kohms, so a finger touch will implode the resistor values). The feedback resistors control the switching power supply's output voltage, so if you touch it while it is running, you can actually cause the output voltage to spike to 100V+ and blow up the power supply as well as whatever you have it plugged into. The second problem is that the pots will shift over time. They are usually not temperature-compensated or age-compensated. So given enough time, the output voltage will go out of spec. And of course, if you bump the sucker the wrong way, the output voltage can wind up going way out of spec. And the third problem is that without a case, these switching boards actually do represent a bit of a fire hazard. They almost always have fuses, yes, but there has to be other forms of protection too and they don't have anything else. -- There are three alternatives. One is to get a fully-potted, locked DC-to-19V converter (19V is the typical laptop voltage). These can be found on amazon. For example, search for "12v to 19v 5a 95w boost converter". Roughly $20. The second alternative is to go with a low power AC inverter that has an idle circuit. Basically, it outputs just tests the water every few seconds and if something eats enough power during the test it turns on fully. (Lower power AC inverters generally have lower idle power draw anyway, but the ones with idle circuits go far far lower). For example, the Victron Phoenix inverter has a 12V 500VA inverter for $150 that has a three-position switch. NORMAL, OFF, and ECO mode. In ECO mode if there are no AC loads the inverter draws only 1W. It does not necessarily play nice with everything, but its a good compromise because AC plugs are really convenient. And you can always just switch it to "ON" mode rather than "ECO" mode if the ECO mode doesn't work out. The third alternative is that if you have a portable power station with a UCB-C output, USB-C can actually output 19V, so you buy a USB-C-to-19V adapter and poof, you are done.

Always a wealth of knowledge!

Thank you! I really appreciate your informative videos.

Thank you sir!

Very good, kind of instructive video. Love it. Way to go Clark. Thanks much on behalf of all "down to Earth" sailors

Great video Clark. Neat toys and good fun. Really enjoyed it.

Great video, as always! Please keep making these videos. More and more and more on electrical stuff!!! Thank you!

Love your electrical and electronics videos.

A buck/boost converter, been using them for years. in DC applications and AC its known as a transformer, Industrial Electrician.

Incredible video AGAIN…. Learned so much!

Perfect! I am doing a test at the dock unplugged, and I need to turn on the inverter to charge my laptop. Then I found this video! I appreciate all you guys do to help us!

Clark delivers again!!

Great video, wish I had been able to watch this a couple years ago before tasking one of these wonder boards with charging my ebike off my truck battery while driving. Your explanation would have saved some experimentation and it looks to be the exact same board which was purchased from Amazon. Keep the videos coming.

I’ve said it before but your content hands down is why I’m so good with my boat…. I will be following your design on my yacht. Thanks

Fantastic!!!

Simply put, AWESOME info!! Thanks

Hi your so good at bringing things down to my level ...Cheers . You seem a lot better health wise . Carry on with the party ...but make sure you tidy up before she returns , I bet Emily left you with a list ?😏

Clark I’ve seen your channel recommended many times and finally YT algorithm fed it to me. Great video!

I use a usb-c car charger from Samsung It do 45watt on usb-c and the laptop charge from it and even use it. I use it on my boat . Samsung model number EP-L5300

As usual your video is wonderful, useful and well made. Is there a video on the build of the your portable battery? If not, I, fir one would love to see one.

I just started following you Clark and very much enjoying your videos. Having lived in my RV for the past 22 years this video especially interested me. I've often thought about how I could bypass running my inverter while using my computer and now I know how to do it. Thank you and keep up the good work.

Thanks Clark. I don't need anything like this right now but I can see possibilities down the road. I did find something at Goodwill that does pretty much the same thing with a bunch of different ends for about $6 but I think it only puts out something lkne 900mA, so not a whole lot of power, but the ends may come in very useful. Keep the good stuff coming buddy.

I don't know what it is but I just went solar and I am finding answers to all my questions including your video on these converters and this has been very informative

Thank you so much, Clark! ❤ I've had one of these converters for a while and have been scared to use it.

Exelent Video.

Mr. Clark, I am impressed with your constant willingness to help your community (Sailing/Boating). You have discovered a way to apply your engineering degree and skills to both sides of the equation -- private sector (commercial products to support your lifestyle, i.e. BankManager) as well as open source information. I am also a engineer (EE/PhD & ME/MS) and enjoy surfing both sides of the wave. For many haters out there, and as we all know there are many, I believe it would aid your message to expand on your academic credentials. Also, for those willing to risk their expensive laptop or monitors on your presentation, it would boost confidence to know you are speaking with some degree of foundation. Personally, I am a fan, your technical post are always informative and deliver value. I hope to press the flesh with you and Em one day. Perhaps I will run across you at the Boat Show in MD this October. I recently ran across a t-shirt by Brittney & Beau (KZfaq) that said -- "Sailing is the most expensive way to get somewhere for free." Gees, this is so true. I wish you and Em the greatest success in your private sector ventures. If you and Em would like to connect, please leave me a comment and I will reach out.

Yup..you a natural engineer, buddy. Good job.

I just went to Radio Shack and bought a cheap voltage converter that converts my boats 12 volts to the required volts of my laptop

Thanks for sharing! Doing a little Arduino project on the boat and preferred running off the start batteries. I was concerned about the voltage drop when starting the engines and the 14+ volts when changing. Nano 33 IOT accepts 3.3 to 21 volts V in. So there must be a buck converter or similar circuit on the Nano board? The on line PDF schematic for the Nano was over my head.

An absolute necessity. The only potential (pun not intended) trouble comes with certain laptop brands that use a third sensing pin in the plug to communicate with and identify their charger being an official one before accepting any current from the plug..! Such brands are best avoided.

Yes this circuits are very handy! But use varistors or suppressor diodes to protect yourself and the Laptop. Only one drop of saltwater can couse a really bad malfunction on this device. It can produce or let through more then 80 Volts. Keep in mind ignition coils work in a similar way.

Been watching your great educational vids! I play with these Chinese SMPS too. One big nasty side effect of these boards and nearly all cheaper Chinese inverters is they have little RFI filtering. Saves $ of course to implement it. Quick way to find out if your power supply/inverter is noisey as far as EMI/RFI emissions is to find an old skool portable AM transistor radio and scroll the dial on AM. Have radio about 6 to 10 feet away from tested device. If you hear buzzing, squealing, and no nearby broadcasting stations, you have a major interference problem! I've had to invest in outboard RFI suppression circuits for both DC/DC converters and my 120 volt inverters. Even my roof top solar uses grid tie inverters that dumped a ton of crappy RFI back into the AC house power lines! After installing good suppression boxes, the interference went way down! I'd sure put a low voltage suppression board on the output of that laptop boost converter to help deliver cleaner power to your laptop. They can be found on eBay and Amazon for under $10.00. The larger capacity 120vac ones can run from $16.00 to $25.00 depending on the current ratings.

For devices less thirsty than computers, I use USB-PD. For DC devices that don't talk USB-PD I use cables that have the negotiator circuits in the cable. But while USB-PD can theoretically match the 18V/90W that my computer power supply outputs, the beefiest USB-PD I've been able to find that can be powered by 12V has a max of 65W. So the Nuc that's my desktop and my laptop have their own power.

Great video Clark... How about USB-C powered devices? Is there a solution?

I lose my train of thought nearly as fast as the switching power supply transistor!

Nice video. Very useful and I need to make one for me. Also, I really need a portable power supply like yours. Can you do a build video? (I do not want to buy a commercial unit.) Your dinghy use is right on for me, also general use for camping, storms, outages, etc. Your consideration is appreciated, but if not interested, any reference to another build video that you like would also be appreciated. Thanks!!

Hi Clark, great video. I have a Dell laptop which unfortunately uses 3 wires, an outer and a pin but also an inner sleeve on the outer ring. The 3rd wire uses some kind of active sensing to determine what power adapter is in use, I suspect it's a serial comm. The point being that if the laptop can't see this signal it will not charge, it will fortunately still use the available power to operate, just will not charge. Off hand I can't remember which contact does which. Just a note for any prospective Dell users.

While most 12V USB sockets don't have a boost converter, we have some on our batteries that do. So all on all of our batteries you can charge laptops at 65W at up to 20V. Not super fast, but sufficient. By the way, I just discovered your channel, I really like it!

So that’s why the cigarette 65w adaptor i took apart had a coil in it. I took it apart because I blew it by feeding +/- back to front. I assume they all dislike that treatment . The cheap ones abound in the last few months, they seemed more of a rarity a year ago.

The nav laptop is a real drain atm. Like to know what the consumption savings is for an appropriate sized inverter and ac power block to the dc-dc. I was going to do it one way or another. Long ago the auto air adapters were not very efficient.

Wouldn't be surprised if the laptops also have some regulators for input.

Otherwise known as boost Dc to Dc converters. Boost means it goes up from 12 to say 20.

Seems like you could have “main DC” at higher voltage (36 or 48) to minimize voltage drop then use buck converters for legacy 12v or lower voltage applications, but would complexity outweigh advantages?

Thanks so much, Clark. I will watch this again after lunch and probably several times when we actually do it :) Our laptop is 19.0V and 7.89A, 150W. So, no worries about the power supply sensing when the battery is full? The battery takes as much as it needs and that's it. Correct? Ours is for an expensive editing laptop, too, so just want to make sure it won't fry. We set the voltage to 19 and that's basically it besides getting the plug's polarity correct. Seems too easy :) Another thing.... Does the potentiometer stay set? Will the constant movement of the boat cause it to slip? Thanks again for making this video. 👍

I love this content! Now I want to build a battery box like you have. Do you have a video on how to do that?

Just spent a week in Desolation Sound and yes the thought did pop into my head: "why am I using an inverter for nothing more than my lap top and son's phone?" Mostly an idle thought because more cruising to do next week :) However, This was something on my todo list to investigate. So thank you for doing the research for me already ;) The next question would be... what style DC plug should I install in a bulkhead to plug into? It seems to me the standard cig lighter plugs, aside from not handling even 5 amps very well might get mistaken for 12V use. While it would be possible to use the little barrel connector like the laptop does, they seem kind of flimsy (from the guitar stomp box building I have done). There are bulkhead mountable anderson outlets but quite large (I was thinking of using one of those for the battery our dinghy runs on). Anyway, great video, interesting as always.

Really good idea! One piece of advice I would give is, if you only use the power of those laptops to video edit and not play games, I would suggest getting an M1 MacBook if you have the budget. They are really efficient. I have used a M1 MacBook Air since 2021, I don't do video edits but mostly CAD and some Excel stuff. It uses about 5-8 Watts while surfing the web and doing mundane stuff and about 12 Watts when playing games or designing in CAD (Autodesk). As far as I know, they are 2-3 times faster than intel processors in video editing, something with the architecture of the chips.

I would like to have seen 2 meters connected. 1 for current. The other for voltage. When charging, we would see amps been drawn. Sometimes we would see a Voltage drop. Ultimately when the current time the amps, we see watts!

Cool video. What about the other adjustment screws? Do you have to tweak them?

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Great info. Thank you. How much battery power do you think you save by doing this rather than using an inverter?

I wish that we could just use 12v for everything in life considering that everything runs on 12v, even monster desktop PCs, run 12v, 5v, and 3.3v respectively.

You can also just buy a mac mini and remove the power supply and run straight from 12v DC. mines been going for 5 years. oh and my monitor runs straight 12v dc

I'm not sure if you have seen the Type C USB cables that have the ability to directly negotiate voltages from USB PD power supplies and have barrel jacks at the other end. I saw them on @AndreasSpiess channel here kzfaq.info/get/bejne/rLKFiNFpnbW8qGw.html. Just another tool in the toolbag!

Very good tip about the cables, and cutting and jointing. I've got lots of spare plugs so now I know what I can use them for. I assume the point of this is that a boost powering a laptop but running from 12 volts, uses less power than an inverter and a laptop mains charger? Is it a significant amount of power to warrant the time and expense?

Question I got a MSI Stealth GS77 laptop that uses a usb type charging port how do you find the right cord for that because the usb is not like a normal usb port its hallow inside as appose to the normal ones which have a small inner part?

Hi Clark. Enjoyed this item. Maybe look at installing but the device appears to be "open", with no cover. So just wondering where you'd site this - even for example shown - using a laptop. I presume you mount it somewhere around nav station? Hidden away to protect parts and from inquisitive inspection.

Great hack. Can this also bee done with the MagSafe connector for Mac computers?

Nice discussion but was hoping to hear some facts about the realized power losses using an inverter vs a DC to DC converter and what this means for a typical cruiser in terms of house bank consumption. I.e. how material are the losses per hour of computer use? Also ironic that the computer itself needs only ~4V which means yet another loss internal to the computer.

Excellent vid, Clark! I’d think that, as an example: 24v battery system, one could distribute to a few choice locations in the boat, then set up a buck converter to something like a USB bus, to provide appropriate power for, say, computer and devices. I’m curious to understand what’s required between converter and USB ports (multi) to allow for different device requirements across these USB ports? A converter for each port? Or is there circuitry best suited as distributor?

How the electronics is wired is one important part of the problem, but how you case it and mount it is equally important. I'm certain you don't just leave it lying loose.

Hey Clarke. This has put my mind at ease for my laptop. I had one of these a while back now and have since lost it. Im curious, do you need to adjust the CC pot at all or just the CV pot. During testing the output seemed erratic when trying to match the amps and voktage required. I am by no means an electronics specialist, just pick bits up along the way with a very basic understanding I need 180w 9.3amps and I thought that was juicy! Thanks for the video. Super helpful :)

Perhaps it went over my head, but what was the efficiency comparison?

You should consider an apple silicon macbook for you next laptop, the battery life/efficiency is amazing and you can charge just off 12 usb PD chargers. With my M1 14" macbook pro I'll often do a day of photo/video editing on battery and still have battery left. My main charger is only AC 100w, but that can charge my mbp to something like 80% in 30 minutes, for an overnight charge I sometimes even just use a 10-20w phone charger.

Hey there! Do you know of where to get a case for one of these? Having exposed electronics flating around like that doesn't seem terribly safe.

I've also been thinking about this before for an desktop computer on the boat. Just because laptops are so annoyingly loud and I need a larger screen anyway. But wouldn't it have made sense to show the real difference of the PC working from the standard AC converter and this thing? I mean measuring the amps going into the ac converter and comparing that with the new one.

Asking for the dingy video bilge pump !!!!

Hey Clark, Thanks so much for the content, your knowledge makes me nervous! Just a heads up, I was looking at some of your recomendations on Amazon and noticed that you still approve the solar vent... that you later dislike..."Failed months after the first saltwater wave hit it. I've been living aboard and cruising for 30 years (Emily and Clark's Adventure on KZfaq). This is a bad product. It's motor isn't protected from salt. I have had to cut it to prices and reworked the electrics and replace the fan. Not worth the effort! But there seems to be nothing good available anymore. I'm going to rework my 30 year old Necro marine bronze vent. It will be less work and I'll end up with something good"'

Thanks for the good ideas. Why don´t you use a car adaptor for your Laptop? I use these to create 19V out of 12V.

Thanks Clark. I was already looking into do this same thing. Did you do any testing to see how many watts you use when connected to the inverter (DC-AC-DC) vs when using the switched power supply. Your laptop is rated for 240W. It would be interesting to see how many it is actually using when you are rendering and have a low battery when connected to AC vs DC. My ASUS power supply is rated at 19.5v @ 9.23A or 200W so pretty similar. Also, do you have any recommendations on a duplex plug to allow the chord to be changed from one power supply to the other?

Great job 8-days later and this unit now costs $25

I can use this on my school bus

Hi Clark, we have the Desk Tops Personnel Computers witch has 110V / 220 V 600 Watts fonts. Can I bypass the AC "area" and supply 12 V DC and have the same output ? I am a Civil Engineer and do not understand these micro circuits.

😎

Wow I have been running on solar and inverter for over three years now, how do I get to buy that piece of a device here in South Africa

Great video...now: " how to power Starlink without inverter !?"

Hi Clark, I run a 12V 0.027 amp computer fan directly wired to my 12 V led battery to vent my battery and diesel lazaret. Is this ok ?

Do you run into corrosion problems on the cheap boards without potting or coatings, or do you have tricks to minimize that?

Great channel Clark. So much practical info. You are a great teacher. What laptop would you recommend for video editing. I'm in need of an up grade.

OK lets be fully realistic here.... And large desktop computer is similar in many ways to a laptop in that most ALL of the components run off DC voltages!! The motherboard, hard drives and DVD ROM drives are all powered by 12 volts DC electric and the motherboard in some cases require a 5 volt DC for start up and other smaller peripherals as well!! Couple this with a LED monitor that requires 12 volts DC like most modern VGA monitors are, and you could even run a full sized desktop off a standard 12 volt car battery, and remove the ITX or ATX power supply completely!!! Older desktop computers even use a 3 volt DC "sense line", that could just as easily be controlled by a small buck converter or a pair of solar powered 1.5 volt DC batteries like those found in a number of cheap pathway lights!!

You kept touching the converter. I kept wincing, waiting for you to get shocked, but you never did. Besides experience, how do you know what you can touch, and what you can't touch when it is plugged in. I would expect you couldn't do the same thing with an inverter. Is that because of AC and higher voltage? What determines which parts have the potential to cause harm?

I thought the same way, and purchased that exact morel of inverter (and FYI ALL buck & boost regulators are inverters by definition). The board is sitting in my "WTAF" pile, because it produces zero voltage on the output, no matter what I do with the adjustment pots. Possibly it arrived with one or more of the power semiconductors already blown, but due to their construction methods (rivet the semiconductors to the heatsink THEN solder) I can't even reverse-engineer it to try replacements. Money wasted. Even though I usually get my money back eventually, I am so sick of Chinese suppliers always insisting on "supporting photos" -(which cannot show what's invisible) before they will start to negotiate a refund. They always try to wear you down with BS, and they've worn me down, so they got to keep my money and I was left with a useless paperweight. Bottom line: nothing is as easy and simple as it seems, including your well-meaning suggestion.

Remember that most of these devices from China are rated at for example 20A max. This means that if your input voltage is 12v and output voltage is 20v your limit would be the lowest of the two making it 12v*20A = 240W instead of 24v*20A = 480W. To make a example of a possible setup: - 12v battery bank - 10A @ 19v requirement for the device you want to power. - DCDC buckboost specified to be capable of 15A. Now lets see if we are in range. Device requires 10A @ 19V = 10*19 = 190W Input into DCDC buck boost 12v so we take 15A * 12V = 180W so here we go over the rating by 10W (or 0.83A if you prefer. = 10W/12V) of what the DCDC buck boost is rated at. If you are unsure about it go with one of the devices that are "constant current / constant voltage" as they would regulate both voltage and current and make sure neither goes above what it's set to and risk getting overloaded. You also have lots of devices on these sites that claim much larger spec's than what they are actually rated for, so try to oversize them with 20-30%. Some also have a much lower efficiency-rating at the top 10% of it's max current so a going with a higher rating may be beneficial in multiple ways. Putting a fast-acting fuse on the output (to your computer) would probably also be recommended with cheap stuff from China as some of the cheap ones can have a horrific failure-mode. For the input it would probably be good with a fuse too, but more to protect the batteries from a short.

I design and make them myself. That way I know for shure they ca n handle the power, are stable and I add often a crowbar and LPF at the output. (And I like doing that, buying one on Ali of Amazon etc will probably be cheaper but I do not trust most China crap)

😃👍👏👏👏

Have you ever tried taking your homemade battery on an airplane? 😂