You have had your phone for months now and you begin to notice that your battery isn’t really holding up like it used to when it was brand new. The battery begins to die by 2 in the afternoon. So, you begin to wonder what is going on with your phone. Is this the bad reviews about the battery life that you heard about? Maybe it was the upgrade that happened to the phone a month ago.
It isn’t either one of those. If you are like most, then you probably had your phone set up in the store, and then took it home to begin using it. When your phone said to charge the battery, you plugged your phone in and when it was charged, you would begin using it again. You were just waiting for that message that stated low battery so you can charge it.
When it comes to most phones, this is the message that pops up around 10% charge. Completely discharging a lithium battery this far will actually give you a battery life of around 300-500 charges, but it will actually begin to lose capacity way before that. You will actually begin to notice after around 150 charges that your battery just isn’t staying as charged as it was. Even if it is just a 5% capacity loss, it could be forecasting what’s coming. Once a year is up, you honestly begin to believe the stories about your phone type damaging the batteries.
The truth is that your battery could have been on a shelf at a manufacturer plant for months after it was made, which puts the charge at about 40%. Once it went to the manufacturer for the phone, it was at 35%, so they charge the battery, and brought it to 45%. They made sure that the battery worked for the phone and then they turned it off and packed it up. It sat around for another few months before you actually bought your phone. 40% is the right charging level for long-term storage, and both of the manufacturers know this, so your battery should be fine. A lithium battery will discharge a bit due to the chemical make up of the battery. This is called self-discharge. Many batteries will have this issue which is why you notice that AA’s that you buy at a store have an expiration date. The more charge that is in a battery, the faster the discharge. If the charge becomes too low, then there are chemical changes that happen which will shorten the battery life. 40% is the best point. It is low enough that self-discharge is quite slow, but its high enough not to shorten the life of the battery by too much.
Now, you are able to get the battery and begin using it.
Usually, you want to charge the phone battery until the phone states that it’s charged, and then another 30 minutes. This is to measure the state of charge of your battery to measure the voltage on the terminals when there is a load on it, such as your phone. This is just an approximation, so if the phone is actually turned off, it is drawing very little current and that isn’t an actual load, so the battery actually seems more charged than what it actually is. Even when it is turned on, which gives a more accurate reading, the charger is pumping more voltage on the terminals of the battery at full charge. It has to, because the current flows due to the difference in voltage. If your battery is at 3.5 volts, and the charger is pushing 3.5 volts, the battery will never charge. The extra voltage is what actually makes the battery charge, and this is what makes the state of charge look better than what it is. The extra 30 minutes is what makes it hit 100% charged.
You don’t have to worry about actually overcharging your battery. The charging circuit in your phone will be able to tell when your battery is fully charged. You aren’t able to accurately measure what it is, but if you are able to watch the change in temperature and voltage over time, which is what the charging circuit does, then it can tell when your battery is fully charged. Then it will shut off, even if the charger is still plugged in or if the phone is still on the charging plate, it could indicate that it is still charging, even though it is not. When the charge actually drops, then it will begin charging again.
You will normally use your phone until it says to charge it. This is something you shouldn’t do. You should never do this, except during conditioning. Never let your battery go under 40% charge. When you begin to let it drop below 50%, is where your battery life will begin to drop. 40% won’t begin to shorten the life enough to actually matter. Frequently discharging the battery to 20%, your battery is only really about half the battery life and frequently discharging to 5%, it won’t even last a year. I am still using the batteries that come with my Samsung Galaxy S4. I always carry 2 of them. If the phone drops to 40%, I switch out the batteries that way I have the phone running for a few more hours before I need to charge it. Besides from long-term storage, my batteries have rarely went below 40%.
I switch the batteries in my S4 every month. On the first month, I will fully charge the phone and then take out the battery and place the other battery in it. Then the other battery becomes my spare battery. You should never carry a battery in your purse or pocket when the terminals are bare. A 2000mAh lithium battery has enough energy to be able to weld your keys to your leg. If you have to carry it with you place it in a plastic baggy, if you don’t have a plastic case to keep it in. In just one month, your battery will lose around 2% of its charge, if you don’t use it that month. This isn’t considered long-term storage. Just place it in your phone and use it. You will see a 98% charge.
Conditioning
A new Li-ion battery needs to be conditioned. This process properly initializes the battery so that it holds as full of a charge as possible. It also helps your phone to properly read the percentage of your new battery.
1.) Fully charge the battery for 7 to 8 hours even if your phone claims that the battery is fully charged. A wall outlet is preferred for the initial charge.
2.) Fully discharge the battery ONCE and then repeat step 1.
The only time that you should fully drain the battery is during this conditioning process or if your phone is not properly reading the battery percentage.
Temperature
You are outside in the cold, in Alberta, Canada. The temperature is negative some number. You’re perfectly fine. 2 pairs of wool socks, thermals, insulated boots, and a 100% down parka. Your phone is in your outside pocket, because in this weather, there is no way you are unzipping your parka to get your phone. The gel electrolyte in your battery is close to being a solid. Your phone rings, so you answer it and your battery that was fully charged when you left the house goes dead in about 5 minutes.
Batteries are similar to people when it comes to temperature. They tend to work best at room temperature. When they hit the freezing point, 0 C (32F), they have lost half their capacity. If the battery still worked at -25 C (-13F), a lithium battery stops working at -20 C (-4F), it wouldn’t have any capacity at all. It is only temporary. Simply warm the battery up, that is assuming that the gel didn’t freeze into crystals which damages the battery and it should be good. When you use the phone when it is cold, even just having it turned on, can drastically lower the battery capacity.
High temperatures are very bad for your battery. If your phone shows a high temperature warning, then turn it off. If your battery comes out, then take it out of the phone. It is very possible for your lithium battery to go into thermal runaway, which is where it will get hotter than it is able to dissipate the heat, which causes it to get a lot hotter, which makes everything so much worse. If you are lucky, then the battery will burst into flames and you will need to replace the ruined battery. If not, then the pressure inside of the battery will build up and then it explodes. The two places that you don’t want this happening are upwind of you and in your pocket. When a battery explodes it will produce a very irritating smoke, which you don’t want to inhale. This is why it is better to actually purchase a phone that has a removable battery. It is better to see a battery burst into flame than watch a very expensive phone melt. Battery damage isn’t actually covered by your warranty. It is for this reason that I purchased a Samsung phone instead of the iPhone. I am able to change my battery in just a few seconds but it takes around 20 minutes with the right tools to change the battery in an iPhone. The only thing that I need to use to change my phones battery is my fingernail.
When it comes to danger, the newer lithium polymer batteries are able to be disposed of safely at a landfill, the harshest chemical is cobalt, and there isn’t much in it, but don’t. There are places that accept batteries for disposal.
Now let’s put some myths to rest.
Myth 1: Calibration
A single conditioning cycle will supposedly calibrate the State of charge. It doesn’t. It has nothing to do with that at all. Calibration actually affects a file, the one that keeps track of which app is using what percentage from the battery. After 10 charges, the file is actually really calibrated. You don’t have to do anything to make it more accurate than it is. You are just wasting your battery and your time.
The indication doesn’t look right? That is because its just an approximation. The actual state of charge can only be found by analyzing the chemicals that are in the battery. The battery stores chemical energy, so the state of charge is “what chemicals are present in what percentages” state. Measuring the voltage across the terminals of the battery with a load on it, is the best that we can do. If the reading is off, that’s because your battery isn’t following the standard charge curve -vs- voltage. This is due to the chemicals in the battery. You can’t correct this and if it is important to you, simply replace the battery.
Myth 2: Fast Charging or charging from 0% to 100% in minutes.
A lithium battery is able to be charged at a 1C rate, the capacity of the battery. If you have a 3200mAh battery, it is able to be charged at 3.2 Amps. The charge from 0%, which should never be done with any lithium battery, to 100% will take an hour plus any inefficiency, turning electrical energy into chemical energy. This means roughly around 90 minutes. The recommended charge is actually 0.75C, so for a 3200mAh battery, the fast charge would be at 2.4 Amps. Many phones are created to charge at around 0.5C. So being able to charge from 50% to 100% at 0.5C is faster than a 1C charge from 0% to 100%, which is around 90 minutes.
You can’t make your battery charge any faster by using a bigger charger. Electricity isn’t pushed by design of the charger. It is drawn by the design of the load. If your phone is meant to draw 1.2 Amps, that is what it will draw, as long as the charger is able to give that much. If you connect it to a 100Amp charger, it will still only draw 1.2 amps. Your house is a 100 Amp charger. A 100 watt light bulb actually draws under 1 amp. The only way that you are able to get your phone to draw more current is to raise the voltage that is coming from the charger, and if your lucky all it will do is destroy your phone. If you are not, you will be able to roast marshmallows in the fire.
The new fast charge phones have just changed what’s inside of the phone to draw in more current, so instead of a 0.5C charge, they are at 1C charge, which if you are treating the battery right it doesn’t matter what the charge is. The fast charge phones are only saving you just a few minutes.
Lastly, the apps that actually saves battery. There are only a few apps that will save any type of battery power and Greenify is one of the best. Apps that optimize or clean RAM on the phone actually tend to use more power than they actually save. I tested plenty of apps and they didn’t actually save power, but cost power. The charge lasted a shorter time running the app than after it was uninstalled.