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. This Blog Is Very Nice Thanks For Sharing Its Very Helpful Data Thank You

    Review My website give some feedback on – https://status-video.com/

  2. This Blog Is Very Nice Thanks For Sharing Its Very Helpful Data Thank You
    Review My website give some feedback on – https://status-video.com/

  3. User Interface and user experience are two fundamental parameters that characterize the achievement of any site or a mobile application. In the event that you don’t have the basic idea about these fundamental Bible lines of web development, you are not going anyplace. In the event that you have made a site or a mobile application and your site or application performs severely on these two angles, you are most likely ill-fated. Every single effort for making the site successful by money, and time spent on the product will go to no end.

  4. Discover Dell PowerEdge Servers. These servers are for businesses that call for value, flexibility and a range of efficiency options and for companies with several servers or limited square footage or storage space, meeting specific organization demands, managing prices and also simplifying management with versatile handling, storage, and networking modules. We are the authorized resellers of Dell servers UAE. We at dubaimachines.com have a wide variety of dell rack and tower web servers with the center of distribution at your front door.
    veritas backup exec partner dubai

  5. Discover Dell PowerEdge Servers. These servers are for businesses that call for value, flexibility and a range of efficiency options and for companies with several servers or limited square footage or storage space, meeting specific organization demands, managing prices and also simplifying management with versatile handling, storage, and networking modules. We are the authorized resellers of Dell servers UAE. We at dubaimachines.com have a wide variety of dell rack and tower web servers with the center of distribution at your front door.

  6. There are certain features in which students can ask for a preview of the assignment before completion to check for any correction and quality. They will be allowed to have a chat with the expert to make any changes or add some extra points if required. Then comes the payment procedure of the assignment help services. Matlab assignment help offers a lot of payment options to facilitate the students to make easy payments. The payments are made before task submission or after getting the task done. And these are some of the quick steps to get help with Matlab assignment help.

  7. En foundation a nuestra experiencia sabemos que los dilemas de fontaner�a se pueden originar en el momento menos apropiado, de ah� que es de suma importancia saber �Cuanto tardamos en fontaneros en zaragoza llegas a su casa? Mantenga la calma, arribaremos al lugar en el menor tiempo posible.

  8. I am using the Flattrade app for long time and I believe it is a good app mainly for the first time stock market investors. It is user friendly and opening account with them is simple and easy. They are not charging for the demat account it is free! and Free equity delivery on all the segments NSE, BSE & MCX. Futures, Options and Intraday they charge only Rs.10 which is lowest among the brokers. I enjoy getting guidance through this app from my dedicated managers for trading. Try https://flattrade.in/

  9. Emily In Paris Emily Cooper Velvet Jacket is in trending product and everyone want to get this article we know we know is Spider Man No Way Home trending movie that is why we are launching this product with affordable price is just for you because we make our customer is first priority you can visit our website.

  10. “Are you searching quality oxygen concentrator hire & sale hyderabad, reachout to us and we have portable concentrators at affordable prices. also, we provide door to door step delivery for hospital & home purpose along with manufacturer warranty. contact us to know more discounts & special offers on philips oxygen concentrator.

    Website: Oxygen cylinder for rent in hyderabad

  11. “Are you searching quality oxygen concentrator hire & sale hyderabad, reachout to us and we have portable concentrators at affordable prices. also, we provide door to door step delivery for hospital & home.

    Website: Oxygen cylinder for rent in hyderabad

  12. I really like your blog. Great article. You should also check out this article.
    write my essay

  13. Are You Struggling in Getting the Free Data Analysis Assignment Sample?
    My Assignment Services provide you the sample & also provide the assignments solutions that include the guidance of experts in every field. Our Australian experts are well qualified, they provide the best academic assistance.
    My Assignment Services provides you with the best data analysis assignment sample.

  14. Belvish is the most trusted perfume boutique, If you are looking to buy branded perfumes for men and women online at heavy discounted price.

  15. Nice and Goregues Services.

  16. AK-A SERIES is Panel-type analog AMMETER with sealable
    terminal cover, suitable for rated current of 5A-100A for direct
    connection, and 5/5A-6300/5A & 5/1A-6300/1A for CT connection.
    Available in 2 sizes, 72×72 and 96×96. Scale is almost linear
    (above 10% readings) with knif edge pointer. Housing is from
    polycarbonate to tolerate high tempratures.Panel Ammeter 96 x 96

  17. If you are searching to hire expert coursework writer for cheap coursework writing,then visit MyQuickWriters to place an order.

  18. If you are searching to hire an expert coursework writer for cheap coursework writing,then visit MyQuickWriters to place an order.

  19. Here the Veterinary Medicine Assignment Help are the best thing which can act as a solution to many of the questions and make sure that any mistakes can be avoided easily.

  20. Lewis is a writer associated with Casita. He has worked for the company for over 3 years and has written for many of their publications. He is a highly skilled writer and has a vast amount of experience in the field.

  21. nice blog..
    The Cash App Phone Number, which would enable you to contact the Cash App service team, is of utmost importance. You should start by grabbing the facts that might turn out to be the ideal component because several factors are frequently in charge of managing the performance of the cash app. You can come up with ideas about how to properly use the currency app. The potential issues with the cash app account are essential because they could occur at anytime. You must decide what will most likely help you fix your problems.

  22. nice blog..i read your blog the information is very help full thanks for sharing this valuable information.

  23. How Do I Access My Cash App Account If Unable To Recall The Username And Password?
    If you are unable to recall the username and password of your Cash App account, you won’t be able to access your Cash App at any cost. So, if you would like to gain access to your Cash App account with no trouble, you should first recover your password with the help of your email account and phone number that must be linked to your Cash App account. Furthermore, you should also come to know about How Do I Access My Cash App Account by contacting the Cash App support executives.

  24. Lahore Call Girls Either way, it is important to know how to choose the right call girl so that you can get what you want and avoid any problems.

  25. Another important consideration is her personality. Is she bubbly and outgoing or more reserved and introverted? Escorts in Lahore

  26. Understanding the importance of the Cash App Phone Number is a crucial component. This is how you should address the cash app, service specialists. If any problems arise with your Cash App account, you may instantly speak with them to resolve them. Such elements are necessary to use the app properly. To receive the solution and send and receive money with ease, your approach must be in the proper direction for the outcome. Since Cash App is a digital system that requires attention, you must make actual steps to use it as needed and to maintain it secure.

  27. Appreciate such technical writing. Such technical writing comes in handy for daily homework needs

  28. Always make yourself comfortable for doing your assignment because a cool and calm mind works better but if you are facing any difficulty then you can take Mechanical Engineering Assignment Help from Great Assignment Helper.

  29. Thank you for giving such useful information that is often difficult to come by. Good job. Excellent article and your website are quite user-friendly. Your website and essay are fantastic. I’m a blogger who focuses on fashion. You can see examples of my work by visiting this website.

  30. Your website is fantastic. This website is really user-friendly. Thank you for sharing your opinions. Please feel free to visit my website.

  31. I Really Like Your Website This Website Is Very easy to use Such Great Work Thanks for sharing your thoughts Feel free to surf my web.

  32. Assignment Desk is an Academic Writing Service company in the UK. We have 1100+ professional writers available 24X7 and can provide assignment help with coursework, essay writing, dissertation help, homework help, thesis help, marketing assignment help, research paper writing, accounting assignment help, case study writing, etc. All the experts in our team are highly experienced and provide a free Turnitin report with all the documents which ensure 100% quality, that too @ affordable prices!

  33. Assignment Desk is an Academic Writing Service company in the UK. We have 1100+ professional writers available 24X7 and can provide assignment help with coursework, essay writing, dissertation help, homework help, thesis help, marketing assignment help, research paper writing, etc. All the experts in our team are highly experienced and provide a free Turnitin report with all the documents which ensure 100% quality, that too @ affordable prices!

  34. For doing the assignments, Law Assignment Help are the best thing to opt for because they can let you do all your assignments in the best possible way. Source: Who can help me in doing my law assignment?

  35. Never be worried about your assignment just because you are not able to complete your work because Mechanical Engineering Assignment Help are there to assist you in every perspective.

  36. The default URL http://tplinkwifi.net is the web address that is responsible to help users access the Tp-Link wifi router. Through this web address, you can connect to the router without an active internet connection. Use a web browser on your computer to login to your Tp Link wireless router through the default URL tplinkwifi.net.

  37. Here at Distinguished.io, you can scan our site to explore the custom software development services 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.

  38. You can find several Escort companies in the city. You can choose one based on price, personality, and other important factors. Escorts in Lahore should have a stable life, good communication skills, and be honest. These factors are essential for a smooth and enjoyable experience

  39. A transcription service https://transcriberry.com/lecture-transcription-service/ is a great way to reduce the burden on your claims team. It can also improve employee satisfaction and retention. These services can also make your back office run more smoothly.

  40. According to IFANCA’s consumer insights survey, which was motivated by the organization’s mission to ensure that everyone has access to the halal goods and services that enable them to live a secure, fulfilling life, more than half of click here mcdvoice Americans who are familiar with halal (52%) and 72% of those who regularly consume halal-certified foods (72%) report encountering challenges when looking for halal-certified foods.

  41. According to IFANCA’s consumer insights survey, which was motivated by the organization’s mission to ensure that everyone has access to the halal goods and services that enable them to live a secure, fulfilling life, more than half of click here mcdvoice

  42. And the time to motivate for our self as well as our knowledge has started. Please keep in touch with us because i want to explore something unique from your side. Ryan Reynolds Shearling Jacket

  43. Flower Bouquets

    December 5, 2022 at 1:19 am

    not only is a link text a safe gift it is also a highly acceptable and evergreen gift to exist

  44. whether it is preparing an assignment or writing an essay, It is a very cumbersome and boring task to do. Would not it be great if you have someone to do the task for you? Well, We have got your back. Hire the experts from a team of dedicated writers to do the job for you, while you are just sitting back and relaxing. Assignmentdesk.co.uk is such a platform you can take help of. It provides all types of assignment help and essay help. Whether it is Your homework or an essay or even your dissertation topic. You can always bank upon us.

  45. Cupidbaba offers premium quality sex toys in Kerala city at very affordable prices for men, women, and couples with 100% privacy. If you are looking to buy, sex toys for yourself and for your partner, then visit their website today. Here is the link: https://www.cupidbaba.com/india-cities/sex-toys-in-kerala

  46. Appreciate such technical writing. Such technical writing comes in handy for daily homework needs however it would be great if you offer Math Homework Help, Economics Homework Help, Physics Homework Help because you hold expertise in such technical writing. Hope you continue to post such technical writings.
    https://www.assignmenthelpservice.com/service/economics-homework-help

Leave a Reply

Your email address will not be published.

© 2024 Jeremy W. Langston

Theme by Anders NorenUp ↑