Lithium ion battery voltage lower than rated.

Discussion in 'General Electronics Chat' started by Gump, Jul 22, 2011.

  1. Gump

    Thread Starter Member

    Jun 7, 2010

    I've got a device that uses a lithiom ion battery which is rated at 3.7V and 1530mAh, however it seems that when I turn the device on it remains on for perhaps 10 seconds or so before turning off. My first thought was it could be the battery, and after checking, it's got a voltage of 2.9V. Now obviously it depends on the device if it could work with such lower voltage, but is it common for a lithium ion battery to have such a wide variance between the rated and actual voltage?

  2. praondevou

    AAC Fanatic!

    Jul 9, 2011
    I don't know if it's common or not, but I've never seen one. Is this a new battery? Have you measured the 2.9V under load?
  3. iONic

    AAC Fanatic!

    Nov 16, 2007
    2.9V means that you really really need to charge the battery. does the phone charger appear to be working? Try measuring the battery voltage after charging for a couple of hours. If it's still 2.9V the you need to buy a new battery or have someone check out the phones charging circuit.
  4. tom66

    Senior Member

    May 9, 2009
    Lithium batteries do not like being discharged below 3V and usually 2.7V is the absolute minimum; beyond which permanent damage to the cell (loss of capacity and increased internal resistance) is very likely.