What About My Battery?

One of the most common questions I’ve received concerns batteries and maintaining them.  People always want to know how to make their battery get through the day, how to help their battery live longer over time, and what to do to avoid a memory effect.  We’re here to help explain what to do, what not to worry about, and how forming a few good habits will go a long way.


The Memory Effect

First, let’s dispel a myth.  The batteries inside your modern phone, which are some sort of lithium ion based battery, do not have a memory effect.  That was something more common with nickel cadmium batteries, which most people were using fifteen years ago.

The best way I can describe the memory effect is as the diminished battery capacity over time.  Think of it like having a bucket, and every time you fill up the bucket, a little bit of sand forms in the bottom.  When the water drains, the sand remains.  Over time, as you refill the bucket over and over again, more and more sand deposits with each refill.  In time, you’ve got a bucket half full of sand, and you can only put so much water in it.  Eventually, the bucket would be full of sand, and you could no longer refill it with water.  This is a non-technical representation of what happens in older batteries - each time you charge, you lose a little bit of space for power, until there’s no place to put power any more.

For this reason, most portable electronics moved over to lithium ion in the last ten years.

I believe, though, that the battery memory myth persists because some of the signs of battery failure in today’s lithium ion batteries resembles the memory effect in older-style batteries.  What people don’t realize (or remember) is that the memory effect started the first time your charged that type of battery.  Lithium ion batteries don’t seem to lose their capacity until later in the battery’s life.  To most, it seems like on some random day, their battery just didn’t hold a charge any more.

So let’s explain why that happens.

The Technical Mumbo-Jumbo

(And Some Super-Awesome Technical History)

If you’re not into technical jargon, try to keep up with me.  I’m going to explain a few things about lithium ion batteries.  It won’t be overly technical, but it does explain a lot about how today’s cell phone battery works.  Oh, and to make things easier, I’m going to abbreviate Lithium Lion battery to LiOn battery.

Many people remember when there seemed to be a different charger for every device, even within the same brand.  After manufacturers moved into early LiOn battery technology, there were a slew of different devices requiring different voltages of battery.  You had big PocketPC phones, which needed more voltage than something like a bar-style Nokia phone.  Some phones had color screens, others had single-color LCD screens.  Some phones had only one screen, while others had two.  And there were some phones with more radio technology inside than others, requiring more power.  The point is, most every phone required a different voltage battery than another phone of the same brand, and as such, needed different voltage chargers to charge them.

See, the LiOn battery is a pretty cool little device.  That’s right, I used device.

Your standard LiOn battery is so much more than a simple battery cell wired up to metal contacts.  Inside that thing is voltage protection.  A LiOn battery cannot have insufficient power, and also cannot have too much power.  The charge cannot be too slow, as with “trickle” chargers, and it also cannot be too fast, as in “rapid” chargers.  The battery has to be charged at a steady, moderate pace, using a charger with little fluctuation in voltage.  You may be surprised to learn that most power converters and chargers do not put out a steady stream of power, but change slightly with electrical conditions, the wiring it’s plugged into, the power grid in your area, and the age of the charger itself.

So with this narrow range of charging power and time, a battery with a higher voltage needed a different charger than one with a lower voltage, unless the two were within the charging range.  That’s why you found early camera phone models with different chargers than their non-camera predecessors - different needs required different charging.  In time, companies started to standardize battery voltages, causing entire brands to be on one charging system rather than five or six.

Then, a few years ago, manufacturers started moving toward smaller phones.  Smaller phones required smaller charging tips, which required new chargers.  For a time, it seemed like charging was about as bad as it was in the early 2000s.  Samsung, only a couple years ago, had at least five or six different charging port types in production.  But that all started to change with USB.

Manufacturers started seeing the benefit of USB, a standardized, common system for data and power transfer.  Early on, phones started using mini-USB, which wasn’t entirely standardized.  But in time, they started using micro-USB - the system most phones use today - because it really was more standardized.  With standardization came cost savings, which also brought consistency to the consumer.

Today, many phones have come to use about the same voltage as any other phone, making universal chargers more practical and functional.  They almost all use the same charging port now, too.  Consistency has replaced inconsistency, making charging similar between all phones.

Now, most chargers are built to be a little less than five volts being sent to the battery.  You can often plug in a phone on another’s charger and be just fine, as long as the charger is within the same five volt range.  Some camcorders and cameras use six or seven volt chargers with a micro-USB tip.  Just because the plug fits doesn’t mean the charger was made for your device.  The power level, in this case, is incompatible with your phone and should not be used for fear of no charge at all, or worse, a damaging charge.

Aside from a proper voltage charge, the other important aspect of LiOn batteries is the time-frame in which it is charged.

In the most basic description of how a LiOn battery works, the charging system is devised to have a constant charge from the 1% level to around the 70% level.  After the 70% level, the charge changes into a “topping off” type of charge,

a little slower and at a slightly lower voltage.  This is done to compensate for the natural discharge of power from the battery (think about how a battery sitting dormant loses its charge over time), as well as the power consumed by the protective circuitry that makes the simple battery a not-so-simple battery device.  The “topping off” charge doesn’t necessarily happen each time it’s plugged in, but as needed by the battery device.

So what does this all mean?

Now that we’re past the technical jargon, let’s summarize what you just read.  The battery needs to be charged consistently.  It must be done with the right type of charger, and not just anything that fits.  You could have the phone plugged into something for days and receive no charge at all, or you could be destroying your battery from the inside-out.  Also, the charge can’t be too fast, and it can’t be too slow.  The original charger for your phone is designed to give your battery the exact charge it needs, in the exact time it needs to be done.

A “rapid” charger only charges you about 70% of the way.  If you were to use a “rapid” charger through a complete charge, you’d actually spend almost the same amount of time you would have spent on a regular charger.  Aditionally, too much power could cause the internal parts part of the battery to change, which causes failure.

Also, a slow or “trickle” charger is useless on a LiOn battery, as an insufficient voltage would likely cause the battery device to go into protection mode, simply because too little power causes the battery to become instable inside, again, causing failure.

This means that the best way to charge your phone’s battery is common sense: let the charger that was made for your phone do the work for you, in the amount of time it needs to fully charge.  This is key to the long-term life of your battery.

The Side-Effects of Charging

Charging a battery, in a sense, is one of the worst things you can do to a battery.  So is letting it sit dormant and lose all power over time.  But you need to charge your battery, obviously, or it’s useless to you.

A lithium ion battery is designed to have a consistent battery life without a memory effect.  But nothing is perfect -even a good design has it’s “Achilles Heel,” of sorts.  Lithium ion batteries can only take so many charges before it’s internal elements are changed and start to fail.  What’s meant by “charging ruins your battery” is that the stuff inside the battery - the elements, the metals, the chemicals - all change with charge and time.  Inevitably, your battery will change to the point of failure.  Once a single cell fails in your battery, you’ll notice less battery life and a quicker charge.  Once several cells fail, the power is greatly diminished and your battery starts to swell.  You cannot prevent this.

Over the years, I’ve noticed an “average” time frame for battery failure, depending on your charging habits.  For most people, they seem to get between 18 months to two years on a battery before noticing the early signs of failure.  If you charge daily, as some have the habit of doing, you’re wearing out the battery’s ability to maintain it’s internal stability, and you might have to replace the battery between a year and 18 months.  If you charge every other day, you significantly increase the amount of time before battery failure.

It’s common sense: once a day, get maybe 300-500 charges, failing after about a year (365 days).  Once every other day, still get maybe 300-500 charges, but you’re only charging about 180 days out of the year, changing the time it takes to reach battery failure.

Most people assume that letting your battery die before charging it will make it live longer.  What I’ve noticed is that this can be true for some, false for others.

I let my phone just about die before charging.  I can go years before buying another battery.  But it’s not because I let it die - it’s because I only charge it when it really needs it.  The more time I have between charges, the more lifetime I have on the battery.  But also importantly, I charge fully.  I don’t charge for ten minutes at work, then ten in the car, and then plug in when I get home.  If I’m going to charge, I let it charge 99% of the time.  Why?  Because a full and complete charge, which the battery is designed for, means I go longer during the day, lengthening my time between charges.  It also means I charge less, keeping the inevitable failure of the battery from happening sooner as well.  I’m maximizing my charge.

How to Maximize a Charge

Here are my tips for maximizing charge:

1) Charge less often, but within your need for battery life throughout the day.  If you have to charge once a day, do it.  If you can go two days and have to plug in the moment you get home on day two, do it.  You’re lengthening your battery’s lifetime.

2) Charge FULLY. Don’t charge partially.  You’re not getting a full charge, which means you’ll have to plug in again sooner rather than later.  You’re charging too often, which will effect the overall lifetime of the battery.  And you’re probably charging two or three times in a day, which would have been solved by charging it all the way the first time.

3) Use the right charger. I’m confident in most universal chargers these days, as long as they’re rated for about five volts.  Just because the charger fits your phone doesn’t mean it’s made to charge it.  Too much or too little voltage will most likely cause the battery to reject the charge, or in the worst case, cause your battery harm very quickly.

4) Use a new charger with each phone. Even with today’s standardized charging ports, there’s still a reason why your new phone comes with a new charger.  Chargers go bad over time.  It’s inevitable.  Power isn’t always a constant, clean connection.  When you keep your charger plugged in, it’s not just running your power meter while you’re not charging, it’s also wearing down the charger’s internal components.  In time, the voltage inside the charger will change, possibly causing harm to the battery (see suggestion #3).  And just because your old phone’s charger tip fits the new phone doesn’t guarantee it has the right voltage to begin with.

5) Use common sense. The people who scramble to charge their phone for only five minutes because they can’t miss a single text from their BFF, or drive around town with their phone always plugged in, or buy something that claims it will charge your phone faster, will all experience early battery failure.  Plug in your phone when it absolutely needs it.  No more, no less.

6) You don’t have to be perfect. An occasional change in charging, such as an incomplete charge, is absolutely fine.  An occasional charge two times a day for an entire week, month, or year is entirely damaging to your phone’s battery.  If you’re charging appropriately 99% of the time, that 1% change isn’t going to kill your phone.

Lastly, if your battery isn’t working as it should, take it in.  If it’s less than a year old, you can probably get a free replacement under warranty.  If it’s more than a year old, buy another one and save yourself a lot of frustration.  But most importantly, if you follow these guidelines with the next battery, you probably won’t have that problem again.

Forming good charging habits is key to a long life for your phone battery.  You’ll have a consistent experience, and a lot less frustration.