Does your battery not last as long as it use to? Can it only hold a fraction of the charge it use to even though it says you're at 100%? If so it's probably time to start looking into replacing your laptops battery.
There are many reasons why your laptop battery starts to fail quicker but the main reason is age. A laptop battery is doomed from the start as their useable life starts diminishing from the day you buy it. All new laptop batteries and most old ones are of the lithium-ion type and it has been the standard for many years. These batteries are here to stay for awhile and I wouldn't expect any major improvements or upgrades to come out anytime soon. If you've hit the point of needing a new battery before you make the purchase here are a few reasons why these batteries fail.
All Batteries Fail in Time
It's the one thing you cannot prevent from happening to your laptop battery. Eventually it will get old just like the laptop and need to be replaced or recycled for a newer one. Manufactures say their batteries are typically good for about 400 charging cycles. This might not sound like a lot but should last you about 1-2 years before you see it's life start to diminish. This might mean instead of 3-4 hours of like you'll get just one or two at best. These are the early warning signs of a failing battery.
There is sadly no way to “restore” a dead laptop battery. You might read that some people try to completely deplete it and recharge the battery a few times in a row. It might sound like a good idea but this is not going to work and you should save the time trying this to find a better deal online for a new one!
How to Extend or Save Your Current Battery
Luckily there are some steps you can take to keep your battery working longer so you can save the money you'd waste on a new battery, and after you see the price you'll want to save that money. Lots of people use their laptop as a desktop replacement, and that means it's always on a desk, couch, etc. and actually doesn't even use the battery. If you always have it plugged into the AC wall adapter this is great for computing power but horrible for battery life. This constant draining and charging of your laptop battery is actually making it's short life even shorter. Like we said earlier a laptop batteries life is determined by the number of charge cycles it will go through, so save it some cycles and just unplug it. With your laptop plugged into the wall it will have zero negative affects on your computing experience and might even improve it!
The other problem with leaving the battery in your laptop while you're running off the wall power is the extra heat. I am sure you have noticed after it's been on your lap for awhile there is a great deal of heat being let off by these little laptops. Keeping the battery unplugged when not needed will keep it from getting hot which is the other big reason a battery will hold a smaller charge. Keep your battery cool at room temperature and don't needlessly cycle it through charging and you'll save a lot of time in the long run.
When the Time Comes to Buy a New One
Once you've tried everything possible to keep that old battery going you will eventually need to buy a new one if you're set on using your laptop away from AC power.
There are many ways you can go about this but I'd recommend looking online because you will find the best deal there. Going through the manufacture is a great way to get an OEM battery but they are not cheap, some batteries are going to cost close to $300! If this is not worth it for you then I'd say to start looking into places like Amazon or eBay. They will sell OEM or used OEM batteries at a fraction of the price you can buy a new one for.
If you're not looking for an OEM battery there are plenty of good options out there. I'd still heavily worn you to not buy the cheapest battery because they will not last. There is a saying you get what you pay for and those are just a cheap plastics shell around some AA batteries, these will wear out quick, hold a very short charger and can even possibly damage your laptop. Saving money is important but don't even look at these options unless you want to run into some battery or laptop trouble.