Why your batteries go bad and how to fix them



So your battery doesn’t last as long as it did.

I am going to give a warning.  I love batteries.  I think they are one of the coolest things that have been invented. I will try not to turn this into a science lecture, but no promises.  Still with me?  Let’s go.

(You can also just skip down to the section about how to make your batteries last longer, if you want)

Batteries run our lives now.  Really, not much we rely on day to day doesn’t have a battery in it.  Think about it, Smart Phone, Laptop, Tablet, your car.  Everything has a battery in it.  I think batteries have had the most improvement over the last few years, even more improvement than the computers they power.

Batteries, at a base level are simple.  They rely on a chemical reaction to move electrons around to provide power to our stuff.  There are a couple of different types of batteries and the chemicals that make them up determine if they can be recharged or are a one time use.  Now the nature of the application for the battery will determine which type of battery you will want to use.

With a lot of our devices we don’t get to pick the batteries.  Rechargeable vs. Nonrechargeable.  NiCad vs Li-Ion.  Size, shape, capacity.  We have to trust that the device manufacturer knows what they are doing when they pick the power for the device you are buying.

Pixel BatterySo what do all the numbers and letters mean?

I am not an electrician or electrical engineer.  I just have a lot of experience with different kinds of batteries.  So if I get some things wrong, sorry.  Please feel free to fill in my knowledge in the comments.

Some of that is easy.  There are some standard sizes of batteries out there.  That’s to make our lives easier.  You should be able to pull any AAA battery out of a pack and it will work in a device that requires AAA sized batteries.  It gets more complicated when you have a specific sized battery for the device.  Your options drop in the number and quality of the batteries available to fit your device.  Like a cell phone.

If you need to replace a battery it is as simple as finding which battery your device requires and replacing it with the same one.  It doesn’t have to be the same brand of battery but it needs to be the same shape.  A lot of battery sizes have been standardized and it would take to much space to list them all here.  If you want to read more about the standard batteries please see the article on Wikipedia.

NiMH BatteryLi-Ion, NiMH, NiCd, Thermal, Lead Acid

What the battery uses as a catalyst will determine how efficient it is and what it can be used for.  Newer battery systems use a liquid polymer for storing energy.  These battery are in a sense, small bags of goo that can hold an electrical charge.  There is a danger to these, if they are allowed to completely run down, they will explode.  They should have a circuit inside that prevents this, but some manufacturers try to get away with this cheap.  This is why you have exploding hoverboards and Galaxy Notes.  The battery either completely discharges and the bag starts to swell and pop, or it gets overcharged with the same result.

These types of batteries are very safe now, but there are some bad examples out there.

Older style batteries use a chemical reaction of two different chemicals exchanging electrons in a liquid to store and then release electricity.  The ironic thing is that these batteries have to have electricity introduced to them first in order to work.  These are the most common batteries you will find.  Your AAAA, AAA, AA, A, C, and D cell batteries (smallest to largest of the common ones) These are the batteries that run your TV remotes, wireless mouse, garage door opener and a host of other things.  They are great for providing a stable power source for a good amount of time.

The downside is that their capacity (how much electricity they can hold is limited.  This is a function of how it is made.  I will spare you the details but these batteries too have come a long way in power and capacity.

The most common chemical for these smaller batteries is an Alkaline.  These are non-rechargeable.  They give a really strong output for the life of the capacity.  The bad part is that, once they are done, they are done.  Please do not try to recharge them, they will explode.  Getting a theme here?

Nickel Metal Hydrides and Nickel Cadmium batteries are rechargeable, they provide good power with a slightly less peak voltage than an Alkaline.   A shortcoming to these batteries is that they can develop a “memory”.  I will talk about how to prevent this and recondition them a little later.

Lead Acid batteries are what you normally find in your car.  I just included them in here to highlight the difference in battery type.  Your car battery doesn’t make your car run.  It just provides the initial power to the ignition to get the engine running so the alternator can take over providing much high voltage to your vehicle, and recharging your car battery as it goes.

Thermal batteries are just kind of cool.  I don’t think they get a lot of attention, since as a consumer you will probably never see one.  I have had exposure to them in my military career.  I will just link to another article on Wikipedia, if you are interested.

This brings us to the Lithium-Ion (Li-Ion) battery.  This is probably the single greatest development in battery technology to date.  It provides for a high capacity, high discharge and most importantly, low weight application.

Laptop BatteryWhy is the Lithium Ion battery special?

The lithium ion battery has allowed for a bunch of different configurations in battery shape and size.  This allows designers to engineer the battery they need to fit the space that is available in their device.  Laptops use these batteries now, which along with the LED backlit screen allows for much thinner designs.  Noticed how the wrist rest section of the laptop has gotten bigger while the keyboard has moved closer to the screen?  It’s the battery.  Rather than being a large NiMH pack under the hinge, the battery has moved to the front.

Smartphones probably wouldn’t even be possible if it wasn’t for the Li-Ion packs.  Their small size and large capactiy allow for faster processors and brighter screens.  And advances in those technologies have made the life of the battery last even longer.

Even the new Tesla vehicles run a Li-Ion pack.   Weight kills an electric vehicle, since you have to expend power to move the batteries along with the car, down the road.  Lighter and better batteries extend the range of the vehicle and provide a better power delivery.

iphone batteryHow to bring your batteries back to life

All rechargeable batteries develop a type of memory.  Meaning if you constantly use your battery (discharge) it down to say 50% capactity and then throw it on the charger, the battery start to only provide peak power over 50% of the capacity.  Put another way, you basically halve the life of the battery.  50% becomes the new 100%.  That great new battery in your laptop that used to last 5 hours, and now only lasts 2, without changing how you are using it?  That’s what’s happening.

Good news is that you can help correct this and bring some of the life back to your batteries.  This is really helpful for devices that the battery can’t be changed by the user.  (Looking at you iPhone)

First off, if you are having this issue, run your phone down to 0%.  Let it die before you recharge it.  When it is done recharging, and as soon as it is done.  Take it off the charger and run it down to 0% again.  The more you can do this, the better you can recondition your battery.

To avoid this in the future, charge your phone in the evening before going to bed.  If you use it as an alarm clock, don’t leave it plugged in all night.  This slight trickle charge will wear down your battery overtime.

An older battery will never come back to a new level of capacity, but maybe you can get a couple more hours out of it.  Your battery needs to be cared for.  You should never really put it on the charger till it gets down to around 10% or less and actually charging all the way back to 100% is not that good either.  You should really pull it off the charger around 95%.

This is not just for your phone

Your tablet has the same type of battery as your phone.  And so does that new laptop.  The number one mistake that most of us make with a laptop is leaving it plugged in when we aren’t using it.  This constant trickle charging kills the life of the battery.  There is nothing worse than grabbing your favorite device and finding the battery dead.  So you have to strike a nice charging balance to keep the battery topped off but not constantly on the charger.  Most newer devices have a great “sleep” feature.  Which means the device is on and ready to go, but is sipping from the battery.

Bottom Line

Taking care of your batteries will go a long way towards extending the life of the batteries in your devices.  Look these batteries power your life.  If you just take care of them a little bit, and maybe change some habits.  You will not find yourself replacing them as often.

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  • Miriam

    Hey thanks, Average Guy Tech! I’m going to try the advice about letting my phone die before charging. I’ve been having the problem of it not lasting and it’s only a couple of months old.

  • Smartin19010

    Good article! Thanks for the info.