Keep that battery going

Last week my laptop battery started flashing a warning recommending that I replace my battery.  I knew it was on its way out – it was lasting less and less time between charges and the day before it had reached the stage where if it wasn't plugged into the power it would drain in about 10 minutes.

Not a problem, all I needed to get a new battery was the model of my computer and the model number of the battery.  I ordered a new battery online which was delivered within 24 hours.  Amazing what a difference a new battery can make to the functioning of your computer.  Back to super quick again.

Having a new battery got me thinking about what I could have done differently to make my old battery last longer – it was about three years old.  A bit of research produced some interesting facts, which everyone who has portable devices (that means everyone!) needs to know.

The batteries inside your laptop, mobile phone, iPad, iPhone, iPod, and some cameras are Lithium-ion batteries.  These batteries are the most popular for mobile devices because…

• They're generally much lighter than other types of rechargeable batteries of the same size.
• More energy can be stored in a Lithium-ion battery than other types of batteries.
• They hold their charge. A lithium-ion battery pack only loses about 5% of its charge per month, compared to a 20% loss per month for standard NiMH rechargeable batteries.

• They have no memory effect, which means that you don’t have to completely discharge them before recharging.

•  Lithium-ion batteries can handle hundreds of charge/discharge cycles.

However, they do have some faults:

• They start degrading as soon as they leave the factory – whether you use them or not.

• They are extremely sensitive to high temperatures - heat causes lithium-ion battery packs to degrade faster.

• If you completely discharge a lithium-ion battery, it is ruined.

•  There is a small chance that, if a lithium-ion battery pack fails, it will burst into flames.

Taking these features into account, what can I do to make sure my new laptop battery lasts as long as possible?

• Fully charge new lithium-ion batteries for the first three cycles.  New Lithium-ion batteries work best if they are fully charged, and drained for the first three charging cycles.  When you get a new battery, or new device, use it until it is completely drained, then charge it fully.  Then do the same another two times.

• After those first three charging cycles you should charge your battery occasionally, for short periods.  Don’t wait until it has completely drained.  Your battery is capable of a finite number of charge/recharge cycles.  A charging cycle means using all of the battery’s power, then recharging it to 100%, but that doesn't have to mean a single charge. For example, you could use your iPad for five hours one day, using half its power, and then recharge it fully. If you did the same thing the next day, it would count as one charge cycle, not two.  Each time you complete a charging cycle, your battery’s capacity is slightly reduced, but it will still take hundreds, up to thousands (depending on the device), of charging cycles before it drops to a noticeable level.  For example, an iPad battery should last 1000 full charge and discharge cycles before it drops to 80% of its original capacity. 

• If you need your laptop plugged in for a length of time, remove the battery (if you are able to).  I upgraded my laptop to Windows 8.1 on Friday, but I was going out for the day, so I plugged the laptop into the power, removed the battery, and left it to do the upgrade on its own.

• If you are not going to use your device for a few months store it with 50% charge.  If you leave a battery with no charge for a few months it may not be capable of holding any charge again.  Also, if you leave a battery fully charged for an extended period the battery can lose capacity.

• Keep it cool.  Lithium-ion batteries don’t like heat.  So don’t leave your devices in a hot car, or sitting in the sun all day, or you might find it has died when you return.  But don’t keep them too cool – freezing temperatures aren't good for them either.

• Don’t be too rough with them.  Impact can damage the battery’s internal cell.

Finally, if you do replace your device’s battery remember to dispose of the old one correctly.  Apple stores will replace and recycle your old batteries, and most local Councils provide e-waste collection and recycling points.  Lithium-ion batteries cannot be put in your normal household garbage.