element14 Community
element14 Community
    Register Log In
  • Site
  • Search
  • Log In Register
  • About Us
  • Community Hub
    Community Hub
    • What's New on element14
    • Feedback and Support
    • Benefits of Membership
    • Personal Blogs
    • Members Area
    • Achievement Levels
  • Learn
    Learn
    • Ask an Expert
    • eBooks
    • element14 presents
    • Learning Center
    • Tech Spotlight
    • STEM Academy
    • Webinars, Training and Events
    • Learning Groups
  • Technologies
    Technologies
    • 3D Printing
    • FPGA
    • Industrial Automation
    • Internet of Things
    • Power & Energy
    • Sensors
    • Technology Groups
  • Challenges & Projects
    Challenges & Projects
    • Design Challenges
    • element14 presents Projects
    • Project14
    • Arduino Projects
    • Raspberry Pi Projects
    • Project Groups
  • Products
    Products
    • Arduino
    • Avnet Boards Community
    • Dev Tools
    • Manufacturers
    • Multicomp Pro
    • Product Groups
    • Raspberry Pi
    • RoadTests & Reviews
  • Store
    Store
    • Visit Your Store
    • Choose another store...
      • Europe
      •  Austria (German)
      •  Belgium (Dutch, French)
      •  Bulgaria (Bulgarian)
      •  Czech Republic (Czech)
      •  Denmark (Danish)
      •  Estonia (Estonian)
      •  Finland (Finnish)
      •  France (French)
      •  Germany (German)
      •  Hungary (Hungarian)
      •  Ireland
      •  Israel
      •  Italy (Italian)
      •  Latvia (Latvian)
      •  
      •  Lithuania (Lithuanian)
      •  Netherlands (Dutch)
      •  Norway (Norwegian)
      •  Poland (Polish)
      •  Portugal (Portuguese)
      •  Romania (Romanian)
      •  Russia (Russian)
      •  Slovakia (Slovak)
      •  Slovenia (Slovenian)
      •  Spain (Spanish)
      •  Sweden (Swedish)
      •  Switzerland(German, French)
      •  Turkey (Turkish)
      •  United Kingdom
      • Asia Pacific
      •  Australia
      •  China
      •  Hong Kong
      •  India
      •  Korea (Korean)
      •  Malaysia
      •  New Zealand
      •  Philippines
      •  Singapore
      •  Taiwan
      •  Thailand (Thai)
      • Americas
      •  Brazil (Portuguese)
      •  Canada
      •  Mexico (Spanish)
      •  United States
      Can't find the country/region you're looking for? Visit our export site or find a local distributor.
  • Translate
  • Profile
  • Settings
Raspberry Pi
  • Products
  • More
Raspberry Pi
Raspberry Pi Forum Rrechargeable AA batteries for pi portable?
  • Blog
  • Forum
  • Documents
  • Quiz
  • Events
  • Polls
  • Files
  • Members
  • Mentions
  • Sub-Groups
  • Tags
  • More
  • Cancel
  • New
Join Raspberry Pi to participate - click to join for free!
Featured Articles
Announcing Pi
Technical Specifications
Raspberry Pi FAQs
Win a Pi
Raspberry Pi Wishlist
Actions
  • Share
  • More
  • Cancel
Forum Thread Details
  • State Verified Answer
  • Replies 7 replies
  • Answers 1 answer
  • Subscribers 665 subscribers
  • Views 1033 views
  • Users 0 members are here
  • batteries
  • rechargeable batteries
  • portable
  • pi
  • aa
  • raspberyy pi
Related

Rrechargeable AA batteries for pi portable?

vinceverc
vinceverc over 7 years ago

Hello guys, i have a very basic understanding of electronics, but don't know much about batteries. So i figured, why not ask element 14's community?

I want to make a raspberry pi portable, and already have some stuff set up.

I am using a raspberry pi model B (yes i am using the rbp 1). And a cheap screen, this is like a 5" screen i got from a Chinese website, it uses around 515 mA when in use. Now i am using retropie and have made a controller that i connected to the gpio pins, i used pigrll (i don't remember the name exactly, it was code from adafruit). Now, as far as i remember the pi uses +- 500mA, this means that this device will use more than 1A. The problem i have is that I need to power this device with some sort of battery. I first thought of a cheap power bank, but the trouble is that most of them can only deliver 1 amp, and i once took one apart, (to use in another project) and accidentally stabbed the battery! This is why i would not like to use one of those again. So I thought, why not use some rechargeable AA batteries, i was thinking of buying four, 1200mAh generic batteries and using these. I was thinking about using two in parallel and two in series. And use a buck/boost converter to bump the voltage up to 5 volts.When i want to charge them, i just take them out and stick the batteries in one of those chargers. There are a couple of reasons i want to use this approach. I am rather scared of using other batteries with custom charging circuits and so on, apart from that, the adafruit ones are hard to buy here. Now, i did some research and found out that the voltage of these batteries drops but apparently the raspbery pi can actually use voltages as low as three volts, only the usb devices won't work, but that is no problem, as i won't use any.

My question is whether this is a good idea, and whether these batteries have auto cut-off to pretend over dischagre.

 

Kind regards,

Vincent

  • Sign in to reply
  • Cancel
  • genebren
    0 genebren over 7 years ago

    This a pretty interesting idea.  I would recommend trying something in a little larger format than AA.  I use a lot of li-ion in an 18650 size (larger than aa).  They come several different capacities (up to ~10000mAh).  You can also get multi-cell chargers for this format.  Given the 4.2V to 2.5V range, if they are in series, you might not need a boost at all. Or you could just run them in parallel (with schottky didodes) and then boost them to 5.0V.

     

    This should work well.

    • Cancel
    • Vote Up +2 Vote Down
    • Sign in to reply
    • Verify Answer
    • Reject Answer
    • Cancel
  • vinceverc
    0 vinceverc over 7 years ago in reply to genebren

    Thank you for the quick response, so would this work with just the AA batteries and not the larger 18650 ones? And the schottky diodes, how should i use them? could i just use normal ones? (sorry i don't know alot about electronics.) And how about over discharge?

    Sorry for the many questions.

     

    Kind regards,

    Vincent

    • Cancel
    • Vote Up 0 Vote Down
    • Sign in to reply
    • Verify Answer
    • Cancel
  • gpolder
    0 gpolder over 7 years ago

    I have very good experience with https://www.piborg.org/power-1137/battborg .

    Input range is 7-36V, so six AA batteries should work very well.

    Max current is 1.5A.

    I'm using eight batteries, which will last a bit longer. Voltage drop isn't an issue as long as the total voltage is larger than 7V.

    1.2V NiMh AA batteries are very robust, over discharge is not such a big problem as it is with LiPo batteries.

    • Cancel
    • Vote Up +1 Vote Down
    • Sign in to reply
    • Verify Answer
    • Reject Answer
    • Cancel
  • genebren
    0 genebren over 7 years ago in reply to vinceverc

    Sure, as Gerrit points out, AA battery would work fine.

     

    The schottky diodes would have been used, in series with each battery, to the common power to the boost circuit, to prevent current flows between cells. Schottky diodes are used do to their much lower forward voltage drops, so that more voltage reached the boost circuit.  To prevent the over discharge, the simplest method is to use voltage detector IC (2.5v) to enable the boost circuit, cutting off battery current flow when the batteries are too low.

     

    This is a proven technique that has been used in several commercial products.

     

    Gene

    • Cancel
    • Vote Up +1 Vote Down
    • Sign in to reply
    • Verify Answer
    • Cancel
  • vinceverc
    0 vinceverc over 7 years ago in reply to gpolder

    Thank you for your answer, I will consider buying one of the modules you linked, since they also are capable of providing enough amps. So you are basically saying I needn't worry about over discharge? And just recharge them when the unit turns off because the batteries are flat?

    • Cancel
    • Vote Up 0 Vote Down
    • Sign in to reply
    • Verify Answer
    • Cancel
  • gpolder
    0 gpolder over 7 years ago in reply to vinceverc

    sure, that is de way I'm using it.

    • Cancel
    • Vote Up +1 Vote Down
    • Sign in to reply
    • Verify Answer
    • Cancel
  • three-phase
    0 three-phase over 7 years ago in reply to gpolder

    Many thanks for the link Gerrit, I will store that away as I have a potential project for a Raspberry PI running on batteries this year.

     

    Kind regards

    • Cancel
    • Vote Up +2 Vote Down
    • Sign in to reply
    • Verify Answer
    • Cancel
element14 Community

element14 is the first online community specifically for engineers. Connect with your peers and get expert answers to your questions.

  • Members
  • Learn
  • Technologies
  • Challenges & Projects
  • Products
  • Store
  • About Us
  • Feedback & Support
  • FAQs
  • Terms of Use
  • Privacy Policy
  • Legal and Copyright Notices
  • Sitemap
  • Cookies

An Avnet Company © 2025 Premier Farnell Limited. All Rights Reserved.

Premier Farnell Ltd, registered in England and Wales (no 00876412), registered office: Farnell House, Forge Lane, Leeds LS12 2NE.

ICP 备案号 10220084.

Follow element14

  • X
  • Facebook
  • linkedin
  • YouTube