Hi there

First thing you should know, this only applies to Lithium Ion ‘smart’ batteries; batteries that are in any of your shmancy new technology devices. That includes you laptop, your smart phone, probably all of your hybrid cars, and your Segway.

Also, this article uses some variation of the word ‘battery’ about a zillion times.

Thirdly, it turns out that there is a lot of variability in how batteries work; it’s not like a light, where it’s either turned on or it isn’t. It is like a light in that some bulbs will last 1 year and some will last 15 years. You just never really know, so you get one and you use it however it works for you, and you know that turning them off when you’re not using them saves energy.

1. How long your battery will actually last
2. How long the gauge says it will last

Number 1: How long your battery will last.

This type of battery has a limit to the number of times it can be fully recharged. It’s a lot of times, but eventually, it won’t hold as much of a charge. That is why, after awhile, your battery just doesn’t last as long. Interestingly enough, there is also a range in how that applies to each battery, so, there is, in fact, such thing as ‘a lemon’. Some of the hardware will degrade faster than others.

However, if you are not planning to keep your device for as long as humanly possible, but rather, plan to buy a new one when they come out, either the next time around or the one after, or so on, this probably will actually never impact you at all, or if it does, very little.

If that’s you, just don’t really worry about how to charge your battery; just use it.

If you do want to try to keep your battery working as long as possible and with as much battery life as possible, then it’s fairly simple:

Don’t run it all the way down and then charge it all the way up frequently. It’s not a big deal if you do this sometimes; you don’t have to be vigilant about this never happening, but simply don’t make it your strategy to always use as much of the battery as possible before charging it. Charge your battery sometimes and then unplug it. You also should not leave it plugged in ALL the time. Leaving it plugged in overnight; totally fine. Basically, just use it like a normal human being, and just keep in mind, if you tend to run it all the way down a lot, you might want to be plugging it in more because it might make it last longer.

2. How long the gauge says it will last.

This actually works in the opposite way of the last thing.

The battery gauge that tells you how much life you have left uses a sensor that monitors how long your phone goes between charges, occasionally updating it’s estimate, and then, based on how much juice you have at a given time, gives you the estimate on what’s left.

That is why, after you’ve had your device for a long time, the battery will die while the gauge still says you have 20% left; the sensor still thinks the battery lasts about the same length as it used to.

To reset the sensor and keep your gauge a little more accurate:

This will refresh the sensor, telling it where the bottom of the range is and where the top of the range is and approximately how long in between.

The advice that made me investigate this, and always had me confused, is when “they" tell you, for your computer, to let it run all the way out, then either wait another 5 hours for the reserve battery to really drain, or to power it down physically and then start the recharge process. I rarely wanted to wait 5 hours for the battery to fully die because, well, I need to use my computer, and I never understood how you could power your computer off when it had already did. So I would have to plug it in and then try to wake it as quickly as it would allow and try to shut it down as fast as possible, so the sensor would not get confused about how much juice was left when it died. This never made sense to me and would cause me the worst kind of anxiety, where it’s completely meaningless, but I wanted to be successful.

Turns out, they say this because, well, it’s not really an absolute that doing it one way or the other way will really give you the exact outcome you’re looking for, so, those are just some things you can do and they’ll probably have some impact on your goal.

What do I do now? Well, I think it’s an interesting idea that I should be able to find 5 hours every few months to not use my computer, and that would give me the best chance at my gauge working properly for as long as possible. But ultimately, it’s not really gonna matter, so I just plug it in, wake it up, shut it down, and then turn it back on and recharge, and be glad that it still works well enough to do that. The reality is, I’m usually fortunate enough to indulge my desire for the most awesome new device, so I upgrade before this is actually a big problem for me. And if I have to wait till this becomes an issue, usually the battery dying before the gauge says it should is the smallest problem that my device has, at that point.

I am not a scientist, so all of this could be totally wrong, but I’ve read a lot of articles about this over the years, trying to figure out this pestering little problem in my life, and this is the summary consensus of what I have found.

I hope it lessens your battery life OCD.

Diatribe, over. Back to what I’m supposed to be doing. You should be, too.