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.


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, 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.


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.


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.


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.


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.





  1. Looking for the best PTECoaching in Brisbane? Our guide provides comprehensive tips and resources to choose the right one. Click here!

  2. Looking for the best coaching in Sydney to help you succeed on your PTE exam? This guide will best place to find qualified and experienced.

  3. Interesting and informative blog post. Keep sharing!!

  4. Interesting and informative blog post for Battery-powered USB Phone Charger. Keep sharing this kind of information.

  5. Informative blog post for Battery-powered USB Phone Charger.

  6. Why is Global Assignment Expert called the best online assignment provider in the world? There are various reasons such as Global Assignment Help have provided expert writers for your assignment development, Get online assignment help with good quality service, delivered plagiarism free work, Very economical prices have been maintained by us,100% confidentiality has been guaranteed, as well as submission before the deadline.

  7. I also wanted to commend the chemistry among the hosts, which created an inviting and dynamic atmosphere throughout the episode. Your genuine camaraderie and enthusiastic exchanges made for a truly captivating listening experience. It’s clear that you not only possess deep knowledge of the craft but also a genuine desire to foster a sense of community within the comic world.

    Thank you for offering such valuable insights to comic lovers and aspiring creators alike. Your podcast episode is a testament to the impact of sharing experiences and expertise to empower others on their creative journeys. I eagerly look forward to future episodes and the wealth of knowledge they’re sure to bring.

    Best regards,
    Visit videowallrentallasvegas

  8. Global Assignment Help aims at providing you with proper information about every single subject related to all assignment help. We believe in providing a perfect assignment with an affordable price range. Our team of assignment experts is highly dedicated and reliable. If you want all in one academic solution then do visit Global Assignment Expert.

  9. In the rhythm of our fast-paced lives, where staying connected is paramount, the battery-powered USB phone charger emerges as a modern lifeline. It’s more than just a device; it’s a bridge that keeps us tethered to our loved ones, work, and the world beyond. With its power coursing through our devices, it becomes an enabler of connections, a source of reassurance in times of uncertainty. In its unassuming form, it holds the potential to light up a heart, to restore a sense of normalcy amidst the chaos. This little gadget symbolizes our resilience, reminding us that even in moments of distance, we are never truly disconnected.

  10. In a world driven by connectivity, the battery-powered USB phone charger emerges as a lifeline of modern convenience. With every charge, it breathes life into our lifelines – our phones – ensuring they never falter in keeping us connected to loved ones, knowledge, and inspiration. This unassuming device holds within it the power to bridge distances, mend hearts, and spark creativity, all while tucking neatly into our pockets. As it revives our devices, it revives our spirits too, allowing us to stay charged emotionally and electronically, ready to embrace life’s every call and message.

  11. This concept is a good way to enhance knowledge and will be recommended this information to my friends. Thanks for explaining it perfectly continue to share your knowledge through articles like these, and keep posting more blogs.

  12. so fantastic solution i am fascinated.

  13. post is unique and interesting

  14. Hi, I’m Megha Malik! What I could say about me? I’m nice Indian girl who likes to enjoy the life

  15. Esplora piaceri nascosti con le affascinanti escort a Verona. Esperte nell’arte dell’intimità, sono pronte a realizzare ogni fantasia.

  16. Esplora piaceri nascosti con le affascinanti accompagnatrice a Verona. Esperte nell’arte dell’intimità, sono pronte a realizzare ogni fantasia.

  17. Esplora piaceri nascosti con le affascinanti accompagnatrice a Verona. Esperte nell’arte dell’intimità, sono pronte a realizzare ogni fantasia.

  18. The main focus of a body to body massage near me lowest price is to promote relaxation, relieve stress, and enhance physical and mental health, you can only find this massage in lowest price at bella spa, so come and enjoy with our best experienced therapists

  19. The main focus of a body to body massage near me lowest price is to promote relaxation, relieve stress, and enhance physical and mental health, you can only find this massage in lowest price at bella spa, so come and enjoy with our best experienced therapists

  20. I recently got my hands on the new battery-powered USB phone charger, and I must say, it’s a game-changer! No more searching for power outlets or dealing with tangled cords. The portability and efficiency of this device are unmatched. Its robust battery life ensures my phone stays powered throughout the day. Truly, technology at its best. For a more detailed review and insights into the latest technological advancements, I always rely on Times Blogs. Their platform offers a comprehensive guide to science, technology, career, and digital trends. Their well-researched content keeps me updated and informed in this rapidly progressing digital age.

  21. Shop The Latest And Stylish Movie Jackets. Available In Verity Of Sizes. All Jackets Are Made With Premium Quality Of Leather.

  22. A judge in Seattle sided with Washington state’s attorney general on Friday and rejected facebook login parent company Meta’s argument that the state’s campaign law runs afoul of the First Amendment.

  23. When searching for the best provider to take your Online Exam Help, it’s essential to consider certain key factors. Look for a provider with a strong reputation and positive customer feedback, indicating their reliability and professionalism. Ensure that they have a team of qualified math experts who possess the necessary knowledge and skills to excel in the subject. Additionally, consider factors such as pricing transparency, timely delivery of assignments, and excellent customer support. Choosing a provider that prioritizes academic integrity, maintains clear communication, and offers a seamless user experience can greatly enhance your online math learning journey.

  24. Looking for the right place to get essay help? You’re on the same boat as thousands of students who seek out professional assistance with their assignments. The good news is, we are here for you! The Online Exam Help from our website is tailored to enhance your experience and aid you in completing all sorts of academic assignments, whether it be an essay, report or dissertation.

  25. I expand my skills as a skilled academic writer to offer excellent university assignment help . I am committed to helping students create assignments that resound with quality and insight since I have a thorough understanding of a variety of subjects like management, engineering, law, nursing, etc., and a commitment to scholarly excellence. I am prepared to offer thoroughly researched, well-structured, and perfectly cited assignments that satisfy the greatest standards of academic writing.

  26. Need an edge in your academic journey? Look no further! Global Assignment Help’s Essay Typer Tool is here to boost your writing prowess. With AI-generated essays, you’ll breeze through assignments and impress your professors. Save time, reduce stress, and achieve academic excellence effortlessly! Try it now and witness the transformative power of our Essay Typer Tool.

  27. Excellent Assignment Help gives science assignment help on time in Australia. Our experts cover all subjects and can provide solutions to any academic problem.

  28. Are you looking for call girls or escorting services in Islamabad? You’re in the right spot. We have a group of beautiful call girls ready to make you happy. No matter if you want a short-term hookup or something more serious, massage, date, spend time with hot girls or build more places to hang out. We have the best service for women.

  29. “Great article! I found the information very helpful. Looking forward to reading more from you.”

  30. Pleasant data! boost mobile phone number have been a distinct advantage for me! I used to battle with dropped calls and slow web speeds at home, yet since introducing a sign promoter, those issues are a relic of past times.

  31. Your blog always delivers insightful content, and this post is no exception. Looking forward to implementing your tipsCómo Conseguir un Divorcio en el Estado de Nueva York

  32. Monkey Type offers an exciting and engaging gaming experience that also serves as a valuable tool for improving typing skills. Whether you’re a seasoned typist or just starting your typing journey. Monkey Type provides a fun-filled platform to develop your speed and accuracy. So, dive into the world of Monkey Type and unlock your full typing potential while enjoying the thrill of the game!

  33. Thank you for the valuable information! I’m writer by profession, If you are looking for dissertation proposal writer in UK. I will suggest you Global Assignment Help for dissertation writing services. Their expertise and support will undoubtedly elevate your work.

  34. This blog is an amazing one, the contents here are always very educative and useful, the reason I make it my regular blog of visit so as to widen my knowledge every day, thanks for always sharing useful and interesting information, you can checkout this I’ve always wondered about this! Loved your advice!! Thanks so much for sharing your expertise 🙂

  35. Fehlermeldungen können manchmal sehr nervig sein. In solchen Fällen ist es notwendig, die Ursache der Fehlercodes zu untersuchen und zu beheben. Wir stellen Waschfehler Ihnen dies zur Verfügung. Alle Fehlercodes für Waschmaschinen finden Sie auf unserer Website; waschfehler

  36. Searching for top PTE exam coaching in Sydney? Discover qualified and experienced guidance in this comprehensive guide.

  37. Thank you for the valuable information! I’m writer by profession, If you are looking for Phd writing services in UK. I will suggest you Global Assignment Help for phd thesis writing service. Their expertise and support will undoubtedly elevate your work.

  38. Nottingham Travel (UK) is a renowned name in affordable airline ticket sales. We partner with major airlines like Qatar Airways, British Airways, PIA and are expanding our services to the UAE. Additionally, we’re planning an open survey with Water Purity and Drinking Water to assess private sector RO water filter machines, contributing to improved water quality standards.

    #cheapflightsBirmingham #cheapflightsBirminghamtoPakistan #cheapflightsNottingham #onlineairlinetickets

  39. Absolutely loved reading your blog post! Your insights on the topic are truly thought-provoking and well-researched. The way you explained was incredibly clear and engaging. I am a assessment help provider with the team of experts. Our dedicated team of experts is committed to providing comprehensive support for all your assessment needs. Whether you’re tackling challenging assignments, writing research papers, or preparing for exams, our services are tailored to help you achieve academic excellence with confidence. We understand the pressures of academic life and the importance of timely submission. Therefore, we offer timely assistance, ensuring you meet your deadlines while maintaining the highest quality and academic integrity. Say goodbye to academic stress and hello to top-notch assistance. With Assessment Help, you’re on the path to success in your educational journey.

  40. KlimaanlageFehler

    September 7, 2023 at 1:58 pm

    Bitte beachten Sie, dass die Beliebtheit von Klimaanlagenmarken und -modellen im Laufe der Zeit variieren kann. Es ist wichtig, die aktuellen Bewertungen, Kundenbewertungen und Energieeffizienzinformationen zu berücksichtigen, wenn Sie eine Klimaanlage für Ihre speziellen Anforderungen auswählen. KlimaanlageFehler Außerdem kann es regionale Unterschiede geben, da bestimmte Marken in verschiedenen Ländern beliebter sind.

  41. Monkey Type offers an enjoyable and interactive way to enhance your typing speed and accuracy. Through regular gameplay, you can develop muscle memory and increase your words-per-minute count.

  42. Explore the Future of Academic Research with 100+ Latest Dissertation Topics!

    Are you ready to embark on an intellectual journey that could shape your academic career? Global Assignment Help is here to inspire and guide you with a diverse collection of 100+ cutting-edge dissertation topics across various disciplines!

  43. Explore the Future of Academic Research with 100+ Latest Dissertation Topics!

    Are you ready to embark on an intellectual journey that could shape your academic career? Global Assignment Help is here to inspire and guide you with a diverse collection of 100+ cutting-edge dissertation topics across various disciplines!

  44. Red Leather Jackets

    September 11, 2023 at 6:03 am

    This is my first time visiting this website, and I am delighted to announce that it is amazing. I have spent a lot of time there and will return. Good luck in the future

    • Discover the ultimate solution for stress-free writing with our Free Essay Typer tool at New Assignment Help. Effortlessly generate well-crafted essays and tackle your assignments with confidence. Say goodbye to writer’s block and hello to academic success!

  45. ในโลกของเกมออนไลน์ที่มีการพัฒนาอยู่ตลอดเวลา มีชื่อหนึ่งที่สร้างกระแสและสร้างนิยามใหม่ของประสบการณ์เกมสล็อต: สล็อต pg soft ด้วยความมุ่งมั่นในนวัตกรรม เทคโนโลยีล้ำสมัย และความทุ่มเทในการมอบประสบการณ์การเล่นเกมที่ไม่มีใครเทียบได้แก่ผู้เล่น สล็อต pg soft ได้สร้างชื่อเสียงให้กับตัวเองอย่างมั่นคงในฐานะผู้นำในอุตสาหกรรม ในโพสต์บล็อกนี้ เราจะสำรวจว่าทำไม สล็อต pg soft จึงเป็นตัวเลือกที่ดีที่สุดสำหรับผู้ที่ชื่นชอบสล็อต โดยนำเสนอคุณสมบัติที่โดดเด่น เกมที่น่าดึงดูด และอนาคตที่จะมีต่อโลกแห่งเกมออนไลน์

  46. Thanks for sharing this amazing content. Assembling tennis shoes and pants can be a troublesome task. Whether it’s the exemplary low-tops or high-tops, you realize how amazing your thin fit pants look with them; nonetheless, matching these two staples of any closet could appear to be a unimaginable assignment! for more checkout: Best Shoes for Thin Jeans.

Leave a Reply

Your email address will not be published.

© 2024 Jeremy W. Langston

Theme by Anders NorenUp ↑