1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Charge laptop battery without laptop itself

Discussion in 'Laptops & Notebooks' started by SentinelAeon, Sep 14, 2016.

  1. SentinelAeon

    SentinelAeon Master Guru

    Messages:
    249
    Likes Received:
    2
    GPU:
    7950 HD
    Hello,

    I am trying to test a laptop, which doesn't work when connected to power supply but is said to work on battery. Sadly the battery is empty so i can't test this. I need to do 1 of the following:

    1) charge the battery without laptop itself, meaning finding out the correct pins/wires coming out of the battery and carefully charge them for a minute or so, just to see if it will turn on the computer.

    2) connect the empty battery to motherboard and supply power to motherboard through external power suply.

    I know this can be dangerous but it needs to be done. Here is the image of the cable that comes out of the battery and plugs into the motherboard. It has 4 black, 4 red, 1 white and 1 yellow wire.

    [​IMG]
     
  2. anticupidon

    anticupidon Ancient Guru

    Messages:
    3,791
    Likes Received:
    607
    GPU:
    integrated
    I will try with my limited knowledge to answer..
    First, to be sure, you need a schematic for your motherboard, to know precisely all power rails, who goes where and what it does, in what order and correct voltages.
    I know, seems a LOT of hassle, but you want to solve this , not make it worse.
    A wild guess: It has 4 black, 4 red, 1 white and 1 yellow wire ...black are ground, red are V_batt_in+ , white and yellow can be data sensing from the pull-up resistor which gives raw data about % of charge left.
    Normally in the schematic you should find where the power rail of charging battery is produced and what exact voltage goes into the battery when charging it.With this info, i guess you can connect black wires to ground and red to positive from a bench PSU with adjustable voltage and amps.

    I can't make it clearly from the picture, but if the 4 red and black wires are conected each to their power rail on the motherboard, you can solder there wires and power the motherboard with the correct voltage.
     
    Last edited: Sep 18, 2016
  3. Extraordinary

    Extraordinary Ancient Guru

    Messages:
    19,327
    Likes Received:
    1,385
    GPU:
    GTX980 SLI
    I think I would be trying to repair the reason it won't power up from the mains adapter, rather than potentially overcharge / explode a battery that likely relies on circuitry in the laptop to maintain a specific voltage/amperage during charge

    Charging a dead laptop battery for a minute or so won't give it enough charge to power up the laptop anyway, you'd need at least 15-20 mins of charging to get it to a level it would boot, and if you're pushing the wrong amount of power to it for 20 minutes, fire could happen

    IMO, fix the charging issue

    Plus, even if you had a 100% charged battery, that's not going to help fix the not charging problem
     
  4. anticupidon

    anticupidon Ancient Guru

    Messages:
    3,791
    Likes Received:
    607
    GPU:
    integrated
    Your aswer is more logic than mine.I was carried away ..
     

  5. Extraordinary

    Extraordinary Ancient Guru

    Messages:
    19,327
    Likes Received:
    1,385
    GPU:
    GTX980 SLI
    :) Well, it's up to OP if he wants to try, your reply was closer to what he was wanting, I saw it as, if someone needs to ask how to charge a laptop battery manually, they shouldn't be trying

    I wouldn't try it either tbh

    Maybe outside on bricks connected to a very long extension lead :)

    Don't think it's as simple as connecting red to red and black to black though, or the power jack from the adapter would just plug directly into the battery, not through laptop circuits first
     
    Last edited: Sep 19, 2016

Share This Page