Lithium-ion batteries (or Li-ion batteries, sometimes LIB, in short) have become the most widely used rechargeable batteries that are used in all kinds of consumer electronics, mainly laptops, PDAs, smart phones, and iPods etc. They have almost completely replaced older types of batteries e.g. NiCd. While they do offer significant advantages over older technologies, these are expensive, and not without their flaws if not used properly.
How long did your first laptop’s li-ion battery last? How long did your second? Having a degraded battery in your mission critical devices can severely damage your productivity, and make it impossible to stay in touch with digital world, on the run. That’s why it is important to know how a li-ion battery works, and how to keep it working in good health, for a longer period of time.
Lets make one thing clear in the beginning. A li-ion battery is going to degrade with passage of time, and finally become unusable, no matter how much care you take of it. This is because of how a li-ion battery works. It keeps on losing its ability to charge to its full capacity with usage. But you can make this degradation process slow, and enjoy a continuous power juice for a good number of years to come, with some careful usage of your battery.
1 – Partial Discharge, as opposed to Full Discharge:
Avoid running down your battery to a complete drain (cut-off point, after which your laptop shuts down). Unlike older battery types, li-ion battery doesn’t suffer from some of the flaws (memory effect) that forced you to run your battery down to a complete discharge before recharging it again. With a li-ion battery, it is recommended to only partially use it, and then put it back on charge as soon as possible.
2 – Regular Calibration:
A side effect of first tip is that periodic partial discharges will make your battery’s fuel gauge out of sync with the battery’s state-of-charge. This will affect different battery status variables reporting incorrect information to you. Thus it is necessary to schedule a calibration cycle once in a while. It is recommended that you calibrate your battery after every 30 discharge cycles. In order to calibrate your battery, use it till it discharges to the cut off point, and your laptop powers off. Let it rest in this state for a few hours. And then power up your machine, and let your battery charge to full. This will get battery’s fuel gauge in sync again with battery’s state-of-charge.
3 – Monitor Battery’s Load Cycles:
A li-ion battery has a specific load cycle number, after which it won’t store charge to its designed capacity. Thus it is important to keep an eye on how many cycles of your battery have you consumed. Every battery manufacturer advertises different load cycle number for its battery. Batteries that come with a Macbook pro, are announced to have a life of upto a 1000 load cycles. And are known to lose its capacity down to 80% after about 300 load cycles. A single load cycle is like using your battery’s 100% charge, even if in multiple sessions. For example if you use your battery down to 50%, and then charge it back, and again use it down to 50%, that will make it lose one load cycle.
There are utilities that will let you monitor different status indicators of your battery. For MacOS, there is coconutBattery. Though numbers reported by such utilities should always be taken with a grain of salt as they are not always reliable.
4 – Storing Your Battery:
It might sound like a good idea to remove your battery from your device, and store it so that its charge cycles aren’t consumed. If you have an alternative guaranteed continuous source of power, this is indeed a good idea. But there are some critical precautions to take in such cases. It is ideal to store your battery in a partial discharged state, having around 40%-50% charge on it. Storing it with a charge less then that might take it to a fully discharged state soon, which would render your battery totally useless. A battery should never be discharged to 0%, as this will render it useless. Devices that use a li-ion battery have special circuitry to cutoff your battery when it reaches a specific discharge point, and doesn’t let it drain to a complete zero, thus safeguarding it.
Also it is important to store it in a cool place. A refrigerator is good, but in that case make sure you seal your battery in a plastic bag to avoid moisture affecting it. Also if you follow this path, on next usage, make sure you let it get back to room temperature before you put it back in the device.
It is also essential to not let your battery stay in unused state for a long period of time. Even if you never need to, you should use it after 3-4 months, charge it to full, and back to half, before storing it again. A li-ion battery, even if not in use, would lose its charge, and there is danger of it hitting a complete drainage.
5 – Avoid Keeping it On AC Power:
Even if you do not plan to store your battery for a long period of time, it is a good idea to remove it from your laptop when it is on AC power. Even though modern circuitry design won’t over charge your battery, but having it on AC power all the time can cause it to heat up significantly more, and thus increase its aging process.
6 – Avoid Too Much Heat, Or Cold:
Too much heat, or cold, are both harmful to your battery. That is why it is advisable never to leave your laptop in a car during a sunny weather as trapped heat would make it lose its storage capacity much faster. Same goes for too cold weather conditions.
Until new battery technologies hit the market that would make our laptops run for years in a single charge, we have to make do with current line of technologies. Even though they may not serve us to our desire, we can still get maximum juice off them with proper care and usage. Following above set of guidelines would make it possible to have your li-ion battery in good health for around two to three years. After which its technological shortcomings would get to it anyway, and render it no more desirable.