Laptop Battery Maintenance and Good Habits – Scientific Studies Reveal

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Feb 05 2009

Laptop Battery Maintenance and Good Habits – Scientific Studies Reveal

Category: speed the web, tech opinion, trust & reputation — jmacofearth @ 7:11 am

As I've been moseying around my home more frequently during the day I have been thinking about my battery usage. In the old days, before LI batteries we had to worry about the "memory effect" if we did not frequently discharge the battery all the way. Today's more powerful batteries don't have a memory problem, but they do die. And in some cases, a lot quicker than I remember my older-NiMh battery. So I asked the folks at my former employer, Dell, to give me some insight into what they know about battery maintenance. I asked the question using Get Satisfaction.

Here are my questions:
1. Should I leave my laptop plugged in while I am at home? All the time? Or should I run the battery down from time to time?

2. So we all have Li batteries now a days, and I know they have no "memory" effect, but I since I am using my Laptop for almost everything and as I travel around the house, should I pull my powersupply along and plug it in. Or should I not worry about it and let it run down and plug it in when it needs to be charged?

3. Do Li batteries have a set number of times they can be charged and discharged before they die? If so, perhaps I should keep my laptop plugged in until I'm travelling.

I would like a technical answer from the DELL tech department if possible. Less marketing speak and more about what's happening and why one method is better than another.

+++

So my friend John B, from Dell was quick to answer, or at least point me to the answer. Thanks John!

John B pointed me to The Battery University. And here are the salient points.

Battery experts agree [I love that phrase] that the life of lithium-ion depends on other factors than charge and discharge rates. Even though incremental improvements can be achieved with careful use of the battery, our environment and the services required are not always conducive to achieve optimal battery life. The longevity of a battery is often a direct result of the environmental stresses applied.

Avoid frequent full discharges because this puts additional strain on the battery. Several partial discharges with frequent recharges are better for lithium-ion than one deep one. Recharging a partially charged lithium-ion does not cause harm because there is no memory. (In this respect, lithium-ion differs from nickel-based batteries.) Short battery life in a laptop is mainly caused by heat rather than charge / discharge patterns.

Batteries with fuel gauge (laptops) should be calibrated by applying a deliberate full discharge once every 30 charges. Running the pack down in the equipment does this. If ignored, the fuel gauge will become increasingly less accurate and in some cases cut off the device prematurely.

Keep the lithium-ion battery cool. Avoid a hot car. For prolonged storage, keep the battery at a 40% charge level.

Consider removing the battery from a laptop when running on fixed power.

@jmacofearth
permalink: http://bit.ly/battery-advice

You will see from the chart below, it's all about heat.

battery maintenance is about heat

click on any of the shiny objects below for a prize

Tags: battery life, battery maintenance, battery usage, dell battery, dell battery advice, discharge rates, environmental stresses, incremental improvements, laptop battery maintenance, li batteries, lithium, lithium ion, longevity, memory effect, memory problem, nimh battery, powersupply, salient points, technical answer

View Comments

www3

the battery on my w500 is losing life pretty fast.
thanx for the article... i realized its probably cuz i use my laptop alot while in bed and it warms up alot!
better keep the temperature level down.
cheers!

John Rasco

Thanks for the due diligence. Just had to replace my laptop battery, so came back to Twitter to find this post. Looks like I'm cool and my laptop needs to stay cool.

The captcha for this post is pain and Princeton. A programmer alumni, no doubt.