Avoid Frequent Discharges To Extend Your Battery Life

Avoid Frequent Discharges To Extend Your Battery Life
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People spread a lot of information about smartphone and laptop batteries these days, but we get a lot of mixed messages, some of which are just incorrect. Here’s how to take care of your battery for the best battery life possible.

Battery-centric website Battery University explains the real relationship behind battery life and charging. Lithium-ion batteries — the batteries present in most modern smartphones and laptops —don’t need to be fully discharged every once in a while to retain battery life, as many of us have been told. In fact, it’s quite the opposite:

Similar to a mechanical device that wears out faster with heavy use, so also does the depth of discharge (DoD) determine the cycle count. The smaller the depth of discharge, the longer the battery will last. If at all possible, avoid frequent full discharges and charge more often between uses. If full discharges cannot be avoided, try utilizing a larger battery. Partial discharge on Li-ion is fine; there is no memory and the battery does not need periodic full discharge cycles other than to calibrate the fuel gauge on a smart battery.

Of course, you don’t want to keep your laptop plugged in all the time, either, as constant charging can bring the life down. They also give a lot of other useful battery tips, like making sure you keep it cool: high temperatures can deplete its life, so you don’t want to store it in a hot car or keep it running resource-intensive tasks for long periods of time. It’s a very interesting article, and something anyone with a laptop or smartphone should definitely read — especially if you haven’t been nice to your battery thus far. Hit the link to to check it out, and be sure to check out other ways to maximise your laptop or smartphone’s battery, too. Photo by Andy Melton.

How to Prolong Lithium-based Batteries [Battery University via Hacker News]


  • Actually the smaller the depth of discharge the more cycles you have, not longer it will last.

    From the linked Battery University site they discussed cycles vs depth of discharge. A smaller discharge means less time your device is operating during that cycle.

    If we assume close to linear discharge to time used, and make the sum of all the time the battery is used with a full discharge cycle as 1 power time.

    A half discharge cycle gives you 1.5 times the total power time of the full discharge.

    A quarter discharge cycle gives you 1.25 time the total power time.

    A tenth discharge cycle gives you 0.94 times the total power time.

  • Hi – heat isn’t good for modern smart phone batteries. When the phone was new I carelessly recharged it in a small gap (of a laptop cushion) and the phone got very hot. So the discovery was made the phone needs to be recharged on a flat surface, so heat can dissipate. Its the first phone I have had that gets really warm when charging. Battery is still ok thankfully.

  • “constant charging can bring the life down” – True but more accurate is that a 100% charge of a Lithium rechargeable battery will decrease the total life of the battery.

    Heat is also the important one. DO NOT user your “power brick” as a laptop stand, this will kill your battery much quicker. Even more so if you do this and never run from your battery.

    If you are not using the battery for a long period, dis-charge the battery with use to about 50% and remove the battery.

    Their other useful information is if you want the longest life of the battery an 80 – 95% charge of it’s capacity instead of the 100% we are use to provides the longest life span (not running time).

    When the Tesla Roadster was released soon after I read an online article from their research team about lithium batteries and the above is what I took from it.

    I personally recommend that for mobile phones if you always have it on when charging, just put it on the charger every day. It will not stay at 100% for long enough to decrease your capacity.

    Laptops on the other hand, at the last half hour of your work day (before you turn it off) try running it from the battery, then in the morning plug it in to let it charge again. This will be better for your battery then leaving the charger in all day and night and is assuming your laptop has an hour of battery life in it or more still.

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