"Ok you bought a brand new mobile phone with brand new battery, after checking its working ok kindly switch it off and charge it fully (100%) then start using it. IT WILL INCREASE YOUR BATTERY LIFE.", said by the Seller.

Is this a myth or absolutely true when talking about Li-ion batteries?


4 Answers 4


That recommendation from the seller was true for old batteries, and it seems they still keep saying that to customers!

Nowadays, batteries are often Lithium-Ion or Lithium-Polymer and such batteries (as I have read many times and based on my own experience) would be stronger if you charge them often. The first time charging and "wait-until-full-discharge-before-recharge" and "don't-use-when-charging" are not applicable to these modern batteries.

Li-Ion and Li-Polymer batteries, if charged often, after about 1 month, would reach to their maximum performance, and you are recommended to charge them every time you find an outlet!

In stock Help application of my Sony Android device, In a section about Battery Life, it reads:

  • Charge your phone often, This will not affect the lifespan of the battery.
  • 1
    Lithium-Polymer or Lithium-ion polymer, not Polymer-Ion. Commented Sep 10, 2012 at 19:05
  • 1
    @evilcandybag Thanks, you are right. Confusing names :) edited.
    – yrajabi
    Commented Sep 10, 2012 at 20:21
  • 4
    Except you are forgetting one thing: Calibration. Modern LiPo batteries have a very flat discharge curve, i.e. the voltage is almost exactly the same independent of the charge level. Thus the phone cannot use the voltage to estimate the charge level. It therefore has to measure how much energy goes in and out of the battery, in order to determine the current charge level. To do this the phone have to charge the battery fully, alt least once, in order to determine the upper bound of the charge level. I.e. if it is not charged fully, it might show 100% charge at a lesser charge than full.
    – bjarkef
    Commented Sep 14, 2012 at 6:31
  • 3
    @bjarkef: calibration only affects the battery meter, the battery life itself is unaffected.
    – Lie Ryan
    Commented Sep 20, 2012 at 17:07
  • 2
    @RyanShillington: Leave it in the charger overnight, and the charge system will usually reset its full charged set-point.
    – bjarkef
    Commented Jan 24, 2014 at 10:07

Li-ion does not need to be fully charged, as is the case with lead acid, nor is it desirable to do so. In fact, it is better not to fully charge, because high voltages stresses the battery. Choosing a lower voltage threshold, or eliminating the saturation charge altogether, prolongs battery life but this reduces the runtime. Since the consumer market promotes maximum runtime, these chargers go for maximum capacity rather than extended service life.

Source: http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries


yrajaby is right.

Other things you have to keep in mind:

  1. follow the instruction about the batery temperature range
  2. do not keep your battery completely discharged for long periods of time
  • 6
    Shouldn't this be a comment on the related answer? Commented Sep 21, 2012 at 5:39
  • 3
    Should it? I thought it was correct to be an answer, because it gave further and useful information and it was not a simple comment, in my opinion.
    – Marco Risi
    Commented Sep 27, 2012 at 10:09

I do research on Li-ion batteries.

Why batteries fade over time is still an issue that is unknown at the fundamental level.

What I can tell you is that there is a solid electrolyte interphase (SEI) which forms upon the first charging cycle. This SEI protects the negative electrode but it is suggested that the SEI leads to fading over time.

If you fail to charge the battery fully the first cycle, the SEI will not fully form and may lead to fading over time. I have experienced this and I really don't think it is a myth.

There is so much info out there. If this is a myth or not nobody will ever know I will tell you this for sure.

P.S. I read that 'battery university' page. It's total B.S. You should read some current scientific papers on the issue.

  • 4
    Have any sources (such as "current scientific papers") that would support this? Commented May 1, 2013 at 18:59
  • Balbuena, P.B., Wang, Y.X. (eds) (2004). Lithium Ion Batteries: Solid Electrolyte Interphase, Imperial College Press, London, ISBN 1860943624.
    – Paul
    Commented Sep 8, 2014 at 10:37
  • 2
    most batteries are charged by factory
    – AquaAlex
    Commented Dec 9, 2014 at 10:35

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