1. Please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more!  
    TalkBass.com has been uniting the low end since 1998.  Join us! :)

USB rechargeable 9V battery

Discussion in 'Effects [BG]' started by synaesthesia, Dec 4, 2013.

  1. synaesthesia


    Apr 13, 2004
  2. At $10 each, no thanks.
  3. ArtechnikA

    ArtechnikA I endorsed a check once... Gold Supporting Member

    Feb 24, 2013
    Sure it can...

    USB - 5V
    AA - 1.5V
    9V - 9V (surprise...)

    It's hard to charge a battery with fewer volts than it's supposed to make.
    Sure, there are various DC-DC convertors, but you typically have only 500 mA to start with from a 'real' USB (as opposed to some charger that merely looks like a USB connector...)
  4. synaesthesia


    Apr 13, 2004

    $10 prolongs the landfllling capacity, or is new technology which minimises landfilling
  5. Maybe, but it's a RIP OFF.
  6. synaesthesia


    Apr 13, 2004
    And you have a source for an equivalent Usb rechargeable 9v battery at a non rip off price where?
  7. synaesthesia


    Apr 13, 2004
  8. MothBox


    Oct 25, 2010
    $10 would buy you about 4 9v Duracell batteries (give or take). I reckon I probably go through 1 batter every 3 months on a pedal... so in a year it would of paid for itself.

    If it can retain its capacity through multiple charges over a couple of years it's worth it. If it degrades to a point where its being charged weekly its a pain.
  9. Except, as already pointed out, you can't do a 9v USB battery.
  10. synaesthesia


    Apr 13, 2004
    They will make one. I use a pedaltrain volto that puts out 9v and charges via a 5v USB, the eneloop pedal juice before the volto is the same. The 9v form will be a smaller version of that.
  11. I see that, interesting. How do they step up DC?
  12. synaesthesia


    Apr 13, 2004
    You'd have to ask them. But someone OEMs for Pedaltrain for sure, and Eneloop are in that business.

    You can step up DC with a chip in a standard circuit, but this is not what they are doing. Several manufacturers make such a chip.
  13. Why not power the internal preamp off a wall wart. A simple wiring trick inside the guitar, a stereo instrument cable, and an inexpensive breakout box (plus the wall wart) is all you need to be battery-free forever.

    Here's a link to a thread about this:

    I've been battery-free for three years now.
  14. ArtechnikA

    ArtechnikA I endorsed a check once... Gold Supporting Member

    Feb 24, 2013
    I'm happy for you but for all the reasons that typically come up discussing this concept, I really don't like it.

    For me and my minimal needs, I can make bigger and better contributions to the ecosystem elsewhere (which I do where it makes sense).

    If I found myself needing more than a small handful a year, I'd seriously look into rechargeables.

    I have no beef with 9V rechargeables, I think it's a fine concept. I do think the USB fixation is a little silly. Does your USB port not plug into the wall? Every time you go through a power conversion step, there are efficiency losses. You want to recharge a 9V battery? Plug its charger into the wall - ta da - one step, few losses.

    Or to be really green - attach it to your big solar panel. We will defer to a different discussion whether the total power produced by a solar panel exceeds its power cost to manufacture...
  15. Once it's done, there's no effort so you can focus on whatever other 'green' activities you wish. There's actually less activity to this because you don't have to buy batteries and swap them out.

    By plugging in rather than buying batteries, you're enabling the power companies and governments to manage the source. I might be solar- or wind farm-sourced already and not even know it.

    The folks that seem to be opposed to this always end up saying "I just don't like it". I have yet to find a good reason not to do this. A valid concern is perhaps the reliability of the extra equipment - wall wart, breakout box - as well as having to use a non-standard instrument cable. There are mitigations for both of those - carry your own extra cables - wire the power source in your pedal board (I did this too) or your amp (another TBer did) so if I were part of a hard gigging traveling band, I'd want something more rugged than my current setup using a breakout box.

    If all the layers of back ups fail, the bass can be returned to normal in no more time than it takes to open and close the battery compartment.
  16. ArtechnikA

    ArtechnikA I endorsed a check once... Gold Supporting Member

    Feb 24, 2013
    OKFine if you have 'the' bass.
    But you want me to do this to all of them, yes?

    And of course - wireless is right out...
  17. Yes this won't work with wireless (supercaps are coming); and the wiring mod is reversible, cheap and quick so there's no reason not to do it to every bass.

    As I said before its more a matter of preference rather than logic.

    The best compromise between the two choices will be a supercap with a voltage regulator but no one is selling something like that yet even though all the technologies are available today. Maybe that will be my next DIY.
  18. boomertech

    boomertech Frank Appleton Supporting Member Commercial User

    Apr 8, 2009
    Syracuse, NY
    Designer/Owner of FEA Labs
    Converting a DC voltage to a higher DC voltage has been around for a very long time. There are many methods to convert the DC voltage, but they all rely on oscillation or a state transition of voltage.

    The coil in a car will send a large voltage spike when the magnetic field is collapsed that creates a spark for ignition. 12VDC to 10,000’s of VDC conversion. Old camera flash circuits work in a similar manner. Taser guns maybe?

    Simple charge pump circuits will charge capacitors and use electronic switching to connect the capacitors stored voltage into the circuit. Since the charged capacitors can be considered mini temporary batteries, they can be electronically switched into the circuit to increase voltage or to provide a negative version of the input voltage.

    In the old days with portable tube equipment, sometimes the oscillators were mechanical vibrators that opened and closed switch contacts that generated the DC pulses. The DC pulses were then converted to the hundreds of volts needed for the tubes with coils or capacitor multiplier circuits.

    But every DC conversion requires the input voltage to be wiggled somehow.:)

  19. Thanks Frank, very enlightening!
    The ignition coil problem just never occurred to me.
    I suppose if this can be scaled down cheaply enough it would work.