Ubuntu – Application to display battery info


First of all, I am not sure the title of this question is the most appropriate however this is what I meant to say,

There are many ways to extend the life of a laptop battery. One way is by not connecting it to the AC adapter all the time which will overcharge it. I read that in this website.

  1. Is there an application which automatically prevents the charging of the battery once it has reached 80% charged? I mean that is such a cool feature. Sometimes people tend to forget to remove the AC adapter and this could diminish the capacity and reduce the life time of the battery.

  2. Does the battery indicator in ubuntu display info or pop-up when the battery is almost dead (dead not in the sense of usage time) but rather a degraded battery?

Best Answer

Wow, that web site is COMPLETELY WRONG. I am an engineer and among other things, sometimes design and build battery packs. I have read many data sheets from battery manufacturers and they all say the exact opposite, and I have experimental evidence that they are correct.

Batteries LIKE being fully charged. If the charger is overcharging them, then it is broken. A correct charger stops charging the battery when it is full, so it is good to leave it plugged in if you can. The more often you discharge the battery, and the deeper you do so shorten its life. A typical battery can handle several thousand cycles if you limit depth of discharge to 30% ( meaning you recharge it once it falls to 70% ). Going to 50% cuts the life of a typical battery down to the 1000 cycle range, and 30% or less drops it to a few hundred. A battery that is fully discharged and remains that way for weeks or months will loose much of its capacity if it can be recharged at all.

Notice the inverse relationship between depth of discharge and state of charge. Battery manufacturers and engineers use the former term. The marketing guy who wrote that web site probably did not understand the difference and so he got it upside down.

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