Jeremy W. Langston

Personal Website

Battery-powered USB Phone Charger

I was getting ready for a long train ride from KY to DC and found out there aren’t any AC outlets for coach seats!  A 15hr ride isn’t too bad when you have a smart-phone; then again, the stock battery on an HTC Incredible will last only about 3hrs of heavy usage.  Not good.  I wanted a way to be able to use it for, well, 15hrs.  So, using some easy-to-find parts I made an extended battery that will charge the phone via USB.  I also wanted the extended battery to be rechargeable.  So, I need to be able to have access to the battery contacts; maybe later I will add something fancier, but for now the battery disconnects from the USB circuitry.  Here’s my finished product, and how to make it.

IMAG0075

I bought a battery from the local Home Depot for $20 (look in the outdoor lighting aisle).  It is 6V and provides 6.5AH.  You can get it cheaper at places like batterymart.com, but I was in a hurry and the shipping on seal-lead acid batteries is not cheap.  The higher the amp-hours (6.5AH in this case), the longer you will be able to run your USB device.

IMAG0064

Now for the voltage – USB uses 5V DC.  I needed to drop the voltage from 6V to 5V, preferably without too much loss.  There are three main options:  voltage divider using resistors, non-switching regulator, and a switching regulator.  In the case of the voltage divider, the resistors basically turn the extra voltage into heat, and they would need to be rated for higher power than the typical $0.01 resistors.  Switching regulators, or DC-to-DC converters, are much higher efficiency, but are more costly.  Also, I couldn’t find one that would work at Radio Shack, so I went with a non-switching regulator:  the 7805.

IMAG0066

The 7805 regulator will take voltages higher than 5V and hold them at 5V, also allowing up to 1A of current.  While that’s much more than is needed, it gives a nice buffer.  A regulator has three legs:  1) input, 2) ground,  and 3) output, where the ground leg is shared between the input and output.  The input comes from the positive side of the battery, the output goes to the 5V pin on a USB connector, and the negative side of the battery along with the GND pin on a USB connector both connect to the ground.  Since the 7805 drops the difference in voltage by heat, adding a heatsink to the regulator might be needed, depending on how much power your device will draw.

IMAG0063IMAG0068

To connect USB devices, I need an adapter that would allow me to plug in a standard USB cable, like the one in your computer.  I happened to have an old PS2/USB adapter from an old mouse.  It hasn’t been used, ever, so I cut it up (the green thing above).  You could use something else, like a USB extension cable which already has wires to solder to.  USB connectors have 4 pins:  1) 5V, 2) Data+, 3) Data-, and 4) GND.  Use some wire to solder the connections (USB 5V -> 7805 Output), (USB GND  and Battery negative -> 7805 Ground), and (Battery positive -> 7805 Input).  Make sure to protect the solder points with some heatshrink or risk shorting, melting, and other bad things.  To connect the wires to the battery terminals, I used spade connectors.  Also, leave the terminals pointing up for reasons I’ll point out soon.

IMAG0067IMAG0069

Once the soldering is done, connect the battery and use a multimeter to check the output on the USB connector (voltage across pin 1 and pin 4 should be +5VDC).  Then you can freely connect a USB device and you’re set.  You could stop here and be done.  Since I wanted this for travel and didn’t want exposed wires, I took it a step further:  enter hot glue.

Clean the top of the battery and add a layer of lubricant (e.g. WD-40) to keep the glue from sticking to the battery.  We want the circuitry to be detachable so that we can recharge the 6V battery using a trickle charger/car charger.  This is why I left the battery terminals sticking up – so that I can freely pull the circuit away from the battery.  I used about 10 – 15 sticks of hot glue used on a mini gun, just to make sure that everything would hold together.  This is the most time-consuming part.  It doesn’t take a lot of thought to do this.  Just fill in all the holes, keeping the USB port accessible.  You also want to keep the heatsink partially uncovered so that it passing air can pull away the heat given off by the 7805 regulator.  You could spend a lot of time getting this pretty by squaring up the sides and making it colored, but this was a last minute project for me.  Hopefully you will get some good use out of this – I know I will.  I hope they don’t kick me off the train thinking it’s a bomb.

IMAG0070IMAG0072

IMAG0077IMAG0078

IMAG0073

50 Comments

  1. Looking for a getaway from the hustle and bustle of Pune? Then book a Manali tour package from Mahadev Tours And Travels! Manali is a beautiful hill station in Himachal Pradesh that is perfect for a relaxing vacation. With our package, you will get to enjoy all the best that Manali has to offer, from stunning views of the Himalayas to adventure activities like trekking and rafting. So what are you waiting for? Book your package today!
    https://mahadevtoursandtravels.com/manali-tour-package-from-pune/

  2. Finance Assignments involves calculations, collectioin and analysis of data. If you ever prepared any assignment in finance then you know the level of frustration while collecting the data and preparing the assignment. Complex calculation can add to the irritation. finance assignments requires specilization. Now you can avail online finance assignment help at your fingertips. Hire from among the experts in the field, and skyrocket your grades.

  3. Finance assignments are one of the most complex assignments to prepare. It is better to hire a subject expert to do the task for you. Now you can avail online finance assignment help at your fingertips. Hire from among the experts in the field, and skyrocket your grades.

  4. Good post, thanks for your information. Have a nice date with VIP models in Ahmedabad for a more romantic date during your alongside. For more information click here: https://www.preeti-patel.com/

  5. nice website… Call Girl in Noida Independent Call Girl Service in Noida Calling 24/7 Escort Service.

  6. We should use an original USB charger for see a better result. And to keep maintain out mobile device safe. Because using other companies’ USB charger can be occurs the problem to a different devices.

  7. Good post, Thanks for giving useful information.

  8. I was read your blog that give a such an inspirational for me. It has good information which i found everywhere but when I saw you blog, I really like it. So, if you are looking for the best a botox medicine you can contact Medcare Aesthetics.

  9. Are you looking for the hottest and most sophisticated escorts in Lahore? Look no further! We have an amazing selection of luxury call girls in Lahore who are available to make all of your fantasies come true. From the beautiful and exotic to the more discreet and sophisticated, our escort services in Lahore have something for everyone. Read on to learn more about the amazing selection of call girls in Lahore that are sure to make your experience unforgettable!

  10. DO MY ASSIGNMENTS
    If you are looking for an online academic writing company to ask them to ‘do my assignment,’ Archlite Assignment service is the right place. We are providing high-quality services at the lowest prices to help students ace their results and complete their degrees with flying colors.
    Many students struggle with their assignments and are looking for expert help with assignments. You must be wondering: can someone “write my assignment for me”? Well, now you need not struggle anymore as you’ve stumbled upon Archlite Assignments. With a professional team of highly experienced writers, researchers, proofreaders, and editors, we have assisted several students so far in submitting top-notch academic papers.               
    From assignments, essays, case studies, theses, dissertations, and PowerPoint presentations, we have subject-oriented experts to work on every given project, irrespective of its complexity. Be it any subject or topic, we can write your assignment with the utmost precision and perfection. Having us by your side, you need to stop fretting over the originality, format, grammar, and timely submission of the paperwork. Just say- ‘do my assignment’ and our professionals will respond quickly with the best quality write-up.

  11. Every learner is prone to committing a few common mistakes. Despite their best efforts, they are always successful in committing them. To resolve this problem, individuals turn to specialised law coursework assistance firms with experienced writers and proofreaders.

  12. In private you will see that I am a very involved, attentive and very hot woman. I am also playful, fun and I like to give myself to the fullest so that we can repeat the experience again. Meet me and will find in me your ideal lover for a discreet escape.
    https://escortswala.co.in/

  13. Call girls in Karachi fall in love and are looking for the right person to settle down with. Even though our Karachi Escort Girls like meeting new customers and spending time getting to know them and what they like, our Karachi Call Girls sometimes fantasies about meeting a customer with whom they will have strong feelings. Our Escorts in Karachi dream about meeting someone who will take care of them so they don’t have to work as an Escort anymore and can be in a loving relationship.

  14. This is such an informative post. Love to read your posts and come across bundles of new ideas. Get your hands on the Course Assignment Help for spotless assignments delivered to you.

    Our assignments stand for
    Anti-plagiarism
    Customizable
    On-time delivery
    24*7n available service.

  15. Assignment making is a process of learning rather than a burden that nowadays students think about. The easiest way to do an assignment is to understand the need or the demand of the question so that an answer to same can be prepared in the required way, yeah, sometimes it might become tough for you to do your assignment and also it might lead you in the state of frustration, but you have to be bold and that boldness can come to you taking help from a acne nursing assignment help which is easily available on the internet.

  16. Excellent blog. Thank you for sharing this information through this blog. Our experts are here to assist with, Assignment Help in the UK. We have a professional dissertation help expert. If you are facing problems in contact us.

  17. Here at Distinguished.io, you can scan our site to explore the Software development companies list that can deliver professional services which can help your brand in maximizing its performance and customer engagement. We conduct extensive research and utilize credible sources to ensure our selection of top companies is legit and the best for clients. Click here for more information.

  18. Assignment making is a process of learning rather than a burden that nowadays students think about. The easiest way to do an assignment is to understand the need or the demand of the question so that an answer to same can be prepared in the required way, yeah, sometimes it might become tough for you to do your assignment and also it might lead you in the state of frustration, but you have to be bold and that boldness can come to you taking help from a Civil Law Assignment Help which is easily available on the internet.

  19. For Tp Link Extender Login process, make sure the Tp Link WiFi extender is powered On. Go to your PC and open a web browser. Type tplinkrepeater.net in the address bar and press Enter. You will be redirected to the Tplink extender login page. Enter the Tp Link extender login credentials in the respective sections and click Login.

  20. ambbet AMBBET SLOT เว็บเดียวครบทุกเกม เว็บตรงมาแรงที่สุด2023

  21. Hi, I am marryalen working as a printer technician. As we all know about HP it’s a huge brand of printer, laptop, desktop etc, But sometimes various kinds of reasons it’s creation little trouble. HP always thinks about their customer satisfaction as well. That’s why they created HP Assistant software,

  22. Have you ever observed a prosperous attorney in action? If so, you must be aware that he is the only person in the courtroom who possesses an equivalent level of confidence, good communication skills, a strong capacity for persuasion, and sufficient efficiency to manipulate the opposition. The lecturer gives the student several law essay writing projects to help them hone these skills. However, they fail to remember that rather than investing all their effort into the essay writing work, these abilities are best developed when they are applied realistically. But who will draught the student’s essay in that scenario? The greatest service for writing legal essays is Instant Assignment Help, to put it simply.

  23. Never hesitate in asking for help from the Project Management Assignment Help because they know how to tackle the different types of questions in assignments which need special emphasis and also they know what is the importance of assignments in the academics, so they put all their all efforts in doing the assignment. Read more: Benefits of studying Finance , Who can help me in doing my law assignment?

  24. Thank you for sharing this article. I found it very inspiring and I’m now going to promote our Virtual Telehealth site. These tips are invaluable.

  25. Hey! Thank you for sharing this article. I found it very inspiring and I’m now going to promote our Virtual Telehealth site. These tips are invaluable.

  26. Hey! I’M Harry I’m a Doctor Thank you for sharing this article. I found it very inspiring and I’m now going to promote our Virtual Telehealth site. These tips are invaluable.

  27. Dr Abhishek Mishra is an experienced orthopaedic surgeon in Delhi for joint replacement surgeries such as hip and knee replacement and arthroscopy surgery as well. You can meet Dr Abhishek Mishra at VNA hospital, Malviya Nagar, Delhi. https://www.vnahospital.com/orthopedics-treatments/knee-replacement/

  28. This battery power is very good. This is the most time-consuming part. It doesn’t take a lot of thought to do this. Thanks for sharing this article. Now it’s time to avail FACE CLEANSER for more information.

  29. Do you have any particular fascination to find and combine with the best Chennai Escorts Agency? If so, you must consider getting in touch with the experts at Pooja Kaur. After working for more than a few years of excellence, the company claims to have top escorts who can help you to meet all your sexual fantasies.

  30. Do you have any particular fascination to find and combine with the best Chennai Escorts Agency? If so, you must consider getting in touch with the experts at Pooja Kaur. After working for more than a few years of excellence, the company claims to have top escorts who can help you to meet all your sexual fantasies.

  31. You want Siliguri Escorts Service Call Girls Models Housewife Female and take Siliguri Call Girl in Escort Call +917595811660
    https://www.piyasen.com/siliguri-escorts.html

  32. Country cheap ammo is a perfect destination for hunting and shooting lovers where users can buy Guns, Ammo, Magazines, Scopes, Holsters and more in cheap rates from various trusted retailers. We have the ammo brands like: Winchester, Federal, Remington, Hornady, Fiocchi and more.

    We have Magpul magazines, Promag magazines, Lancer magazines and Glock magazines.

    A large range of Handgun, Revolvers, Shotguns, Rifles Rimfire, scopes and Holsters.

  33. Mechanical Assignment Help
    Mechanical Engineering is a discipline of design that cares for the examination, planning, assembling, and maintenance of automatic frameworks. It abuses the standards of engineering, materials science, and physics to accomplish its motivation. We are offering the best quality mechanical assignment help to resolve all assignment and homework writing-related issues. So get help at a very cheap price to safe your pocket and relief from writing headaches.
    It is the branch of engineering that creates and uses heat and mechanical power for the planning, generation, and operation of machines and tools.
    We provide the best work to you with promising quality, without plagiarism, without error, and fresh information, the best reasonable prices, and well-organized and adequately referenced work.
    We are one of the Mechanical Assignment Help specialist organizations in the alliance. Providing the alternates from such a significant number of years is the only intention that retains us at best, and understanding styles us efficiently.
    Our group of experts is amongst the most experienced and best chosen from the most significant public institutions in the world. Each author grasps a Ph.D. or Master’s degree in the back & contains the particular hands waged in this arena from previous numerous years. Their knowledge never lets our client’s reckoning depressed and influences us to main the move by their exertions.

  34. Here was a beautiful and well-maintained treatment center.
    I have nothing but positive words about the staff, the facility is beautiful and their treatment plans for residents helped save my life.

  35. McDonald’s survey and feedback portal strives to encourage people who complete a customer satisfaction survey and get real consumer feedback.https://mcdvoiceo.shop//

  36. Are you looking for the perfect date tonight in Islamabad? Look no further! Here we present to you a list of 10 model girls you can call in Islamabad tonight. Whether you’re looking for a dinner companion, a tour guide, or simply someone to keep you company, these model girls are sure to provide you with the ultimate experience. From beautiful models to experienced escorts, you’ll have your pick of the bunch. So read on and find out who you can call girl near me tonight for the perfect night out!

  37. i am happy to see this fabulous website

  38. This is really informative post. Great work.

  39. Thanks for the wonderful information I was looking for this information for my mission.

  40. Nice knowledge gaining article. This post is really the best on this valuable topic. the christ

  41. I have forgotten the Orbi default password. What to do? It is for the login and setup process. Connect the power adapter to your Orbi RBK43 router. And then, plug the power adapter into a power outlet. If the Power LED of your router does not light, then make sure that the power adapter is in your router and power outlet. After that, go to the http://www.orbilogiinn.com page

  42. I have forgotten the Orbi default password. What to do? It is for the login and setup process. Connect the power adapter to your Orbi RBK43 router. And then, plug the power adapter into a power outlet. If the Power LED of your router does not light, then make sure that the power adapter is in your router and power outlet.

  43. I am tired of sleeping alone, you are the one who makes me sleep in your arms. My partner should be such who can calm the fire of my youth and satisfy me.

Leave a Reply

Your email address will not be published.

© 2023 Jeremy W. Langston

Theme by Anders NorenUp ↑