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Electronics Laptop Battery charge without laptop...

Discussion in 'Modding' started by RinSewand, 27 Nov 2009.

  1. RinSewand

    RinSewand What's a Dremel?

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    Hi,

    Wondering if you guys could help out here (Specifically those with a bit of electronic knowledge!)

    We have at work, a lamp for our video camera, however, this never arrived with the correct power source. The only thing we have that will power it that's mobile is a 14.8v laptop battery. We've got this to work fine connected to the lamp, however we're struggling to charge it using the laptop charger. We've established that the battery has 4 pins that each take 3.3v, but obviously the charger provides a full 14.8v.

    I'm thinking some sort of circuit - but don't know enough about circuit deisng to throw one together. We've got access to PCB making facilities and various electronic parts...

    The laptop battery is an RM A42-A6, which is actually a rebadged asus.

    cheers for any ideas / help!

    RwD
     
  2. bigsharn

    bigsharn Officially demotivated

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    I don't know how well it'll work (or how safe it is) but if you use/make a transformer you should be able to get the thing to work and charge prefectly, I can't work out the ratio for lack of maths skills, but ah well
     
  3. steveo_mcg

    steveo_mcg What's a Dremel?

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    If its lithium i would very very careful using anything but a designed charger. Li-on batteries can go pop very easily. You can get balance chargers from your local rc shop then you'll have to work out how to hook it up to the batter.
     
  4. Smilodon

    Smilodon The Antagonist

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    As steveo_mcg says, it sounds like Li-ion or li-po batteries. They tend to have individual inputs for each cell. It should also say "li-po" or "li-ion" on the battery pack.

    And I would say that since you are asking this question you shouldn't try to make a charger as those things could explode and/or catch fire if charged incorrectly. The chargers you can buy have monitoring of each cell to protect them.

    Having that said, you could check this out: http://www.candlepowerforums.com/vb/showthread.php?t=57999

    Just remember that the battery pack could have some internal circuits that could affect how the charger will work and how it have to be wired. The safest thing would be to charge each cell individually. (One at a time, not all at once with 4 chargers)
     
  5. Solidus

    Solidus Superhuman

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    Just get another lamp- it's not worth burning the building down over it...with that much effort your willing to put into making a charge- surely a new lamp or alternative would be easier?
     
  6. RinSewand

    RinSewand What's a Dremel?

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    Thanks for the replies guys...

    The cost of the powerpack for the lamp we have / an equivalent lamp far outweighs the cost/effort of doing it this way. I shall assume from the responses that 'we can't do this'. Taa. Will find a way round it...

    RwD
     
  7. Marci

    Marci Ex-O-CuK / ThermoChill

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    A new lamp and power source will cost in the region of £500. Not an option. The effort required for making a PCB to interface the current charger with its battery (to replace the interface provided by the laptop itself) requires free labour and possibly some components of a total value of £10...
     
  8. mvagusta

    mvagusta Did a skid that went for two weeks.

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    You could get two 7.2v rechargeable battery packs for r/c cars hooked up in series for 14.4v, which can be a cheap option, but even cheaper is do you have the laptop?

    Maybe you have the laptop but it's buggered and won't charge the battery? If the laptop's not worth fixing, you could try to remove the pcb/connectors so you can hook up the battery to the charger.
     

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