1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

USB Battery Array -> Power 36v Motor

  1. Sep 7, 2015 #1
    I'd like to take several of these (or similar) usb device charging batteries (http://www.ianker.com/product/A1271011 [Broken]) and connect them into an array to create a minimum of 36V and channel that to power a speed controller for an electric vehicle. Is this possible? Would I be able to prototype something like this with an Arduino or similar? Any advice/direction would be really appreciated.

    Question 2: if this is possible, do the amp hours added together per battery or does that stay a constant? For example, a battery has 2 amp hours - if I have 5 is it a total of 10 amp hours or is it still 2 amp hours?

    Last edited by a moderator: May 7, 2017
  2. jcsd
  3. Sep 7, 2015 #2


    User Avatar
    Gold Member

    The Watt hours add together. 72 Whr x 7 = 504 Whr
    If they are in parallel, the amp hours add together, but the voltage stays at 5V. parallel 7 x (5V , 20 Ahr) = (5V, 140 AHr) equivalent 700 Whr
    In series the voltages add, but the amp hours stay the same. series 7 x (5V, 20Ahr) = (35V, 20Ahr) equivalent 700 Whr

    I assume the discrepancy in Whr is due to the fall in voltage during discharge. The conservative 72 Whr per unit is likely to be correct. So
    in parallel 504 Whr / 5V = 101 Ahr
    in series 504 Whr / 35V = 14.4 Ahr
  4. Sep 18, 2015 #3
    maybe I'm missing something but a charger needs to be plugged in to do anything. wouldn't that be an issue for any vehicle application?
  5. Sep 26, 2015 #4


    User Avatar
    Gold Member

    The device linked to by the OP is a battery pack that is designed to charge portable devices. Thus a charger. It also likely comes with a plug in type charger. Thus a charger charger.

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: USB Battery Array -> Power 36v Motor
  1. Motors and batteries (Replies: 10)

  2. Cyclops Array (Replies: 1)