[Solved] Should I Leave My Laptop Plugged In All The Time?

[way12go]

Should you leave your laptop plugged in and charging when you're not on-the-go? What's best for the battery? What's best for your user experience? Read on as we investigate.

When your laptop's battery is 100% charged, should you leave it plugged in so any battery power doesn't get used, or will that cause overcharging, overheating, etc.? Should the laptop be unplugged when the battery level is 100%?

When I'm at home, is it better to use the laptop plugged into AC power, or with just the battery, for the overall battery life?

So what was the verdict? Should you leave your laptop almost perpetually tethered to the wall or only charge it when the battery charge is running low?
The Answers

It won't make all that much difference. What will shorten battery life is temperature: If it gets hot, it will shorten the battery life. Best thing to do, if you are able, is to remove the battery while you're at home and keep it somewhere cool.

If it's a Li-ion battery, then they don't like to be completely discharged, so make sure you charge them regularly. Wikipedia:

Lithium-ion batteries should not be frequently discharged fully and recharged ("deep-cycled"), but this may be necessary after about every 30th recharge to recalibrate any electronic charge monitor (e.g. a battery meter). This allows the monitoring electronics to more accurately estimate battery charge. This has nothing to do with the memory effect.

Top 15 Ways to Extend Your Laptop's Battery Life

Laptops tend to lose their charm quickly when you're constantly looking for the nearest power outlet to charge up.  How do you keep your battery going for as long as possible?  Here are 15 easy ways to do so.

1. Defrag regularly -  The faster your hard drive does its work – less demand you are going to put on the hard drive and your battery.  Make your hard drive as efficient as possible by defragging it regularly. (but not while it's on battery of course!) Mac OSX is better built to handle fragmentation so it may not be very applicable for Apple systems.

2. Dim your screen – Most laptops come with the ability to dim your laptop screen.  Some even come with ways to modify CPU and cooling performance.  Cut them down to the lowest level you can tolerate to squeeze out some extra battery juice.

3. Cut down on programs running in the background.  Itunes, Desktop Search, etc.  All these add to the CPU load and cut down battery life.  Shut down everything that isn't crucial when you're on battery.

4. Cut down external devices – USB devices (including your mouse) & WiFi drain down your laptop battery.  Remove or shut them down when not in use.  It goes without saying that charging other devices (like your iPod) with your laptop when on battery is a surefire way of quickly wiping out the charge on your laptop battery.

5. Add more RAM - This will allow you to process more with the memory your laptop has, rather than relying on virtual memory.  Virtual memory results in hard drive use, and is much less power efficient. Note that adding more RAM will consume more energy, so this is most applicable if you do need to run memory intensive programs which actually require heavy usage of virtual memory.

dvd Top 15 Ways to Extend Your Laptops Battery Life

6. Run off a hard drive rather than CD/DVD - As power consuming as hard drives are, CD and DVD drives are worse.  Even having one in the drive can be power consuming.  They spin, taking power, even when they?re not actively being used.  Wherever possible, try to run on virtual drives using programs like Alcohol 120% rather than optical ones.

7.  Keep the battery contacts clean:  Clean your battery's metal contacts every couple of months with a cloth moistened with rubbing alcohol.  This keeps the transfer of power from your battery more efficient.

8. Take care of your battery – Exercise the Battery.  Do not leave a charged battery dormant for long periods of time.  Once charged, you should at least use the battery at least once every two to three weeks. Also, do not let a Li-On battery completely discharge. (Discharing is only for older batteries with memory effects)

9. Hibernate not standby – Although placing a laptop in standby mode saves some power and you can instantly resume where you left off, it doesn't save anywhere as much power as the hibernate function does.  Hibernating a PC will actually save your PC's state as it is, and completely shut itself down.

temp Top 15 Ways to Extend Your Laptops Battery Life

10. Keep operating temperature down - Your laptop operates more efficiently when it's cooler.  Clean out your air vents with a cloth or keyboard cleaner, or refer to some extra tips by LapTopMag.com.

11. Set up and optimize your power options – Go to 'Power Options' in your windows control panel and set it up so that power usage is optimized (Select the 'max battery' for maximum effect).

12. Don't multitask – Do one thing at a time when you're on battery.  Rather than working on a spreadsheet, letting your email client run in the background and listening to your latest set of MP3′s, set your mind to one thing only.  If you don't you'll only drain out your batteries before anything gets completed!

13. Go easy on the PC demands – The more you demand from your PC.  Passive activities like email and word processing consume much less power than gaming or playing a DVD.  If you've got a single battery charge – pick your priorities wisely.

14. Get yourself a more efficient laptop -  Laptops are getting more and more efficient in nature to the point where some manufacturers are talking about all day long batteries.  Picking up a newer more efficient laptop to replace an aging one is usually a quick fix.

15. Prevent the Memory Effect - If you're using a very old laptop, you'll want to prevent the 'memory effect' – Keep the battery healthy by fully charging and then fully discharging it at least once every two to three weeks. Exceptions to the rule are Li-Ion batteries (which most laptops have) which do not suffer from the memory effect.

Bonus Tip #1: Turn off the autosave function.  MS-Word's and Excel's autosave functions are great but because they keep saving regular intervals, they work your hard driver harder than it may have to. If you plan to do this, you may want to turn it back on as the battery runs low. While it saves battery life in the beginning, you will want to make sure your work is saved when your battery dies.

Bonus Tip #2: Lower the graphics use. You can do this by changing the screen resolution and shutting off fancy graphic drivers. Graphics cards (video cards) use as much or more power today as hard disks – Thanks Andrew

Update 7/7/07: Bonus Tip #1 to give caution about turning off autosave, tip #8 to change information about discharging batteries – thanks to all who pointed it out. Added Bonus tip #2, Tip #1 to add in clause in regards to Mac OSX, Tip #1 about the spinning of hard drives – thanks to all who pointed it out

How do I maximize my battery life?

When I first got my laptop (8 mos. ago) my battery life was about 2 hours 45. Now after daily use (mostly with plug but using battery as well) it is down to 1.5 hrs which is basically useless. I have tried draining totally recharging etc and still only 1.5 hours. SO I am buying a new one. My question is how do I make my battery keep its charge so I can have it when I need it?

I originally wanted to title this article "Why does my battery life suck?", because I know that's exactly what it feels like when the battery life gets shorter and shorter. My oldest laptop has about a 20 minute lifespan, so in many ways the battery is really nothing more than a glorified UPS. Not that that's bad, but it does limit the laptop's portability.

I turned to a friend, Jerry Foutz, for some help on this one. Do a Google search for Power Supply Design, and Jerry's site, SMPS Technology, is the top result. Jerry knows power supplies.

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It turns out that the single, most important aspect to maximizing battery life is something that I wouldn't have thought of: matching the battery to its charger. In Jerry's words: "Make sure your battery and charger match and you have a quality charger. About the only way you can maximize the probability of this happening is to buy both from the computer manufacturer for the exact computer model."
"...even small differences in output voltage of the charger can have dramatic impact on the lifespan of your battery..."

Apparently even small differences in output voltage of the charger can have dramatic impact on the lifespan of your battery, by either under, or over-charging. "If you get a low-cost charger and it is off by as little as 10 mV (millivolts, 1/1000 of a volt), you will also get less than optimum performance." An example Jerry shared is that a 4.1V cell charged at 4.050 V might be good for 4,000 charge cycles. Increasing the charge voltage to 4.250, a difference of less than 1/4 of a volt, can reduce this down to less than 100 cycles.

I had no idea that batteries were that sensitive.

I'm also glad that I've purchased my batteries, extra batteries, and chargers from the manufacturer at the time I got my laptop. That, further, minimizes any manufacturing differences that may occur over time.

The number two factor in battery life? Temperature.

The fact is that laptops just aren't designed for ... well, for laps. If you look at the bottom of your laptop you'll see it probably has feet (or more likely, bumps or rubber pads) that lift it off of any flat surface you might put it on. That creates very important space for ventilation. If you block that space, with say your lap, it's likely that you'll be causing the laptop to run hotter than it should. If you do this regularly, you'll likely shorten the lifespan of the laptop's batteries.

Again, in Jerry's words: "If you have your laptop on your lap and it is burning you, you are shorting the battery life and charge-cycle capability because you have interfered with its cooling system."

If you do like to use your laptop on your lap, there are various "laptop desks" out there that will provide you a flat, or even grooved surface (for even more space and air flow) on which to comfortably place your laptop. My wife and I actually each have a laptop desk from LapWorks.

Temperature cycling - allowing the laptop to become very cold and then warm, repeatedly - say by leaving it in your car overnight in cold weather regularly can also adversely impact the battery's life.

A concern that I've had for a long time is whether or not leaving a laptop plugged in for extended periods of time would harm the battery. Today's designs pretty much expect that type of usage, so it's not the issue I was afraid it might be. Good thing, too ... my laptop is plugged in and running pretty much 24x7.

Finally: "All this assumes a well designed power supply (including charger and battery). Unfortunately, not all designs are perfect and the layman has almost no way to judge the quality of the design. You pretty much have to trust the manufacturer and his reputation."

Thanks again to Jerrold Foutz for contributing to this article.

What about the "Remove the battery!" camp? It turns out that while removing the battery can be beneficial, the situations in which it is beneficial are fairly limited. Splattne writes:

The answer is: YES and NO, it depends on the situation.

Having a battery fully charged and the laptop plugged in is not harmful, because as soon as the charge level reaches 100% the battery stops receiving charging energy and this energy is bypassed directly to the power supply system of the laptop.

However there's a disadvantage in keeping the battery in its socket when the laptop is plugged in, but only if it's currently suffering from excessive heating caused by the laptop hardware.

So:

    In a normal usage, if the laptop doesn't get to hot (CPU and Hard Disk around 40ºC) the battery should remain in the laptop socket;
    In an intensive usage which leads to a large amount of heat produced (i.e. Games) the battery should be removed from the socket in order to prevent unwanted heating.

The heat, among the fact that it has 100% of charge, is the great enemy of the lithium battery and not the plug, as many might think so.

The best plan of attack then, is to monitor your hardware to ensure you're not overheating your battery and be concious of the limitations of the type of battery in your device–for the majority of users, a Lithium-Ion battery.