Need Suggestion on Powering Smart Phone.

Discussion in 'General Electronics Chat' started by paul.1911, Mar 17, 2015.

  1. paul.1911

    Thread Starter Member

    Mar 25, 2012
    Hi guys,
    I've a phone which runs at 3.7v 1400mA battery. The battery gone dead and there is no new battery available on the market.
    So for some purpose i'm looking forward to power up my phone on DC adapter by connecting its terminal to phone's battery terminals. I have a DC adapter which outputs at 3.6v 250mA. My question is, it safe to power up a phone with an adapter?
    Is this output is safe for my cell phone with no risk of burning or damage?
    I took my phone to its service center, i saw a guy who power up my phone where there is an amp meter attached to a battery. I saw that the phone was using about 405mA of power.

    Pls suggest. Any suggestion is most welcome. Your suggestions are very valuable to me.
  2. wayneh


    Sep 9, 2010
    I'd keep looking for a battery. Using a battery with the proper voltage will allow you to use your existing charger and also avoid making yourself a power supply that you have to tether to. Worst case is a similar battery that maybe doesn't fit, but works electrically.
    paul.1911 likes this.
  3. Dodgydave

    Distinguished Member

    Jun 22, 2012
    your phone will power up with the correct voltage as long as the psu will deliver the current, what battery number is it?
    paul.1911 likes this.
  4. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    If your phone draws 405mA then the 250mA supply is obviously inadequate.
    paul.1911 likes this.
  5. paul.1911

    Thread Starter Member

    Mar 25, 2012
    Actually i didnt noted the battery number. I gave it in service center for replacement under warranty, its been over a month, when i am calling them they are saying company doesn't have it in stock. And another problem is no other model from same company shares the same size of battery. So cant find it anywhere else nor online. The phone is in no use from more than a month.
  6. paul.1911

    Thread Starter Member

    Mar 25, 2012
    Yeah i acknowledge that its not upto the mark. But what i was thinking if there is any problem giving it a try? I dont want to take a risk of damaging it, i dont have knowledge about circuits thats why need advise on this.
  7. Roderick Young


    Feb 22, 2015
    What exactly is the model of the phone, and what part number does the battery have on it? It's actually pretty amazing what you can find on eBay, if you haven't looked, yet. Home-built power or a portable recharger pack might work to power the phone, but it would seem to be inconvenient having the phone tethered to the external device at all times...
  8. PlasmaT


    Feb 19, 2015
    It will be far better to give up the phone I guess in comparison to the price of the phone and the inconvenience caused. But as a land phone may be useful.
    So try to get a replacement batter, until then you can try this:

    Get a different phone battery of your choice. Almost all li-ion batteries used for phones have the same voltage. the power capacity does not matter I guess, higher the better. Attach the battery to the outer cover of the phone and then attach the + ve and -ve wires from phone to external battery. Do not use solder iron, you may explode the external battery.

    I am not sure about the middle wire where the phone senses the temperature. If you are trying to charge it from the phone you may need it, else the phone may not charge the battery.

    This method will be far better than connecting the phone to a wall adapter. Besides safe as well.
    Last edited: Mar 18, 2015