New DS Mod in the works. Built in 2nd Battery

Discussion in 'NDS - Flashcarts and Accessories' started by rrg, Feb 15, 2009.

  1. rrg
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    rrg Member

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    So here is what I have so far. I just started.

    I yanked out the GB slot and removed the pointer holder inside the DS.
    Next I am fitting a second battery that will be flush as you can see in the pic.

    The pic shows one of my broken clear case bottoms that now hold the battery, perfect for illustration purposes.
    Now I will attempt to solder wires to the 2nd battery EDIT: (no switch, batteries are now wired in parallel also added 2 bright LEDs and switch to use it as a flashlight at night.) and run it to a switch so I can charge each one at a time.

    I am not done because I want people to look at it and see if an ideas pop up.

    The mobo still works. It's not all put back together. I need a new case before I can finish it.
    enjoy.
    PS: You will need to forget about GBA carts.

    DS bottom with 2 batteries
    2nd pic
     
  2. da_head

    da_head A dying dream..

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    hmm interesting. so how does it work? does it utilize the second battery after the first empties? or does it simply double the battery life?
     
  3. Isaiah

    Isaiah The Conductor

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    That's.... THAT'S AMAZING ME WANT NOW!!!!!
     
  4. rrg
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    rrg Member

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    No the way it will work is one at a time. I will use a double pole single throw micro switch that will pick one battery at a time.

    So to charge it you will need to pick one, fully charge it, than flip switch full charge the 2nd one.

    You then can run one down all the way then, I would turn off the ds hit switch and repower it on now on the second battery.

    Never will the DS see more than one battery of power.
     
  5. Arno

    Arno GBAtemp Regular

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    That's great, except I'd like to see a way to still use the GBA games, perhaps by some extension ribbon cable that you could put in there, or something similar.
     
  6. dinofan01

    dinofan01 Misses the old days...

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    This sounds pretty cool for long trips. Especially when using a flash cart.
     
  7. UltraMagnus

    UltraMagnus hic sunt dracones

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    I guess that is the most simple way to do it. you could put the batteries in parallel, but you would need a charge levelling circuit. a circuit to flip between the two batteries is possible too, but I can't think of a simple one off the top of my head.

    you may have problems where when you flip the switch and both batteries are briefly disconnected. a largish power capacitor between the positive end of the switch and where the battery normally connects to the DS motherboard should solve that.
     
  8. Brian117

    Brian117 GBAtemp Psycho!

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    Wow.

    This is so a mod I'm going to do in the future when instructions come out.

    So you've tested this and it's fully working?
     
  9. rrg
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    rrg Member

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    Imagine the LED possibilities on a clear case if this works well.
    You could dedicate one battery full time to running the LEDs alone.

    I will be adding one LED to try this out.

    I still need to collect all the materials. ie. wire, shrink wrap, connector, switches and new ds case.
     
  10. ZenZero

    ZenZero GBATEMP's regular arse.

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    this looks extremely useful, but i can't see myself doing it, i use guitar hero too much.

    it looks great!
     
  11. rrg
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    rrg Member

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    OK I did some more research and have discovered that the parallel battery will work as long as the mAh is the same for both batteries. The two batteries will level each other out if connected and left alone for a period of time before I apply them to the DS. Then the charger (circuit) will just see one 3.7v with double the mAh battery.

    I believe that the charger will work because in order for the DS to work with 900mAh, 1000mAh and 1800mAh batteries it must rely on current draw feedback from the battery to tell it to stop charging.

    Or it might also be an a timer circuit to prevent over charging. I don't know about that one yet.

    Feedback welcome.
     
  12. rrg
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    rrg Member

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    OK, I have a small update:
    Since I am adding the battery in parallel all I did was put a positive and negative wire on the mobo going to the second battery to the gba slot. This will eliminate the need to go to a switch.

    Here is how I did that. The touch screen still fits pretty good with the wires behind it.
    Solder job of wires to mobo pics.

    Now the tricky part is getting the battery to fit flush behind the GBA cover to the DS on the 2nd slot. I need to get my dremel out and trim the plastic lip on the cover.