On Battery Life

On Battery Life

By the Numbers.

We no longer can live without our devices of convenience.  All of which require frequent charging of their batteries to remain active.  Over time the batteries grow weaker and eventually fail.  And most times this leads to replacing the device.  Whether that is preplanned obsolescence or adopting the latest and greatest technology is your call.

There are steps that can be done extend the battery life of your favorite device.  Put another way, avoiding things that are damaging the battery.

My formal training is with electronics and as such, I have worked on a variety of electronic/electrical equipment, including battery chargers.  Most recently with a company called Lithium Battery in Plymouth Meeting, PA.  They make specialized batteries for things like submersibles.  Over the years I have observed numerous behaviors about batteries and evolved strategies on mitigating them.

Here are some thoughts you may want to consider.  Some of these are easy to implement, others border on being a pain in the ass.  They are not "all or nothing".  Just decide on the ones you wish to follow. 

Batteries will get weaker over time.  This is unavoidable as batteries store energy chemically, and over time the chemicals dispersed in the structure, or the structure is weakened and breaks down.  As the chemicals are stored in a cellular  pattern, individual cells break and become useless, but the remaining cells is holding charges, and so the battery gets weaker, but doesn't fail.

#1)  Don't leave your device on the charger over night.  

Chargers are, by and large, built by the lowest bidder, and as such, are probably very cheap, and cheaply built.  Leaving the device on the charger over night will cause the battery to over charge by a very small amount, for a long period of time.  Overcharging will cause the battery to weaken sooner.

The truth is, battery chargers do not "Know" when the battery is charged.  Cheap ones from the dollar store will just pump full power until bad things happen.  More advanced ones, like what comes with your cell phone has some ways of monitoring the situation, by temperature and power storage estimates, and will reduce the charge to a trickle when the battery is thought to be near fully charged.  This greatly extends the life of the battery, but is not perfect either.  

One way to tell if this is happening is when you take your phone off the charger first thing in the morning. Is it warm to the touch? If so, it was over charging the battery.

Anecdotal story:  I was issued a new company laptop way back when.  And I used it to entertain my son on a long drive.   I didn't have the ability to charge the laptop from the car.  I put in a DVD of a movie and took off.  The DVD ran the whole movie and just about died when we arrived at our destination.

Next year, same trip, same laptop.  The battery died half way to the destination.  The backup battery also ran flat before arriving.  One of the differences is that laptop was on a charger 24x7 for a year.  

Anecdotal story:  In 2017, I received a company laptop, a Microsoft Surface.  Which I basically used as desktop.  At home, it rarely left the cradle, but I also spent half my time on the road, so it wasn't on a charger 24x7.  About a year later, the batteries expanded (swelled, bulged), causing the case to round and rock.  But those batteries were now compromised and at risk of fire and explosion.  I called Microsoft, and even though the unit was out of warranty, they replaced the unit and copied over the drive for free.  While waiting for the work to complete, I found out that they had a warehouse full of these compromised units.  This is a major problem for Microsoft.  Over the next year, all four of the units we bought in 2017 failed in a like manner.  

I did Google search on this problem, I see units still being reported with battery "Swells", but many of the victims are reporting older models, and so are in the range of when our units were purchased.  I also found a reference just last year of firmware changes to prevent overcharging in Surface units.  My thought is that Surface batteries are still a problem, and I would not recommend buying one.

#2)  Don't charge your device to 100%

As you get closer to the battery capacity, the battery will also be damaged by a very-very small amount.  And over the years this adds up to a degradation of the charge.  For my phone, I only take the charge to 80% and then remove it from the charger.  It seems to work well.  My phone is now 4 years old and the the battery effectiveness is still rated at 80%.

I realize this tactic is in the range of "Pain-in-the-ass".  And I don't have a measured difference between taking it to 80%, and taking it to 100% before removal.  Once again, it's your call.

Now the companies know all this and do their best.  When your device is at 100%, it is not really at full charge.  It's at 80%(ish)  They set it that way to protect the phone from fully charged damage.  So when I remove the phone at 80%, it's closer to 64% of the real charge.  And for my needs, that is good enough.

And example of an excellent charging system is the Toyota Prius.  When introduced in 1997, there was a fear that they would be replacing their battery packs at 5 years, costing $3,500 (1997) and creating an environmental problem disposing of 110 pounds of lead acid batteries.  

And that didn't happen.  After 5 years, Prius's batteries were at about 80% effectiveness, more than sufficient to provide hybrid assist when needed.  Toyota accomplished this by really babying their batteries.  They spent significant R&D on the charging system.  In the end, they keep the charge on the batteries between 40-60%.  We know this because hypermiling enthusiasts modified Prius's to accept full charge in their efforts to get more MPG out of them.  And it worked, but we have no stats on how long the batteries lasted.

#3) Run on battery if you are using an external display.

The display is the major consumer of power of a laptop or phone, by a lot.  If you are using an outboard display/keyboard/mouse etc... then the battery will run all day long with normal usage.  Charge the laptop to about 80%, then unplug it.  

#4) Don't leave your device in the car.  

The trunk is OK, but the passenger compartment gets very hot, shortening the life of the battery.  I had a Garmin GPS unit on the dash board for about 10 years, it's last 5 years the battery was just enough to boot up and die.  In the end, the batteries were so dead, that even being on a power cord, it wouldn't boot up. 

Your car battery also suffers in the summer heat.  That is when it suffers the most damage. You only notice the problem in the winter because a cold engine needs more current than a warm engine to start.

Running battery saving modes.

There are many settings to help extend the length of the charge.  In essence, they all reduce performance and energy usage, but come up to full power when the device is in use. 

Which ones you should use is situational to you.  How mobile are you?  If mobile, and away from  convenient charging, then use them all.  Dim the screen a bit, slow the processor, set sleep for 5 minutes.  

If you are on a docking station. Turn them all off.  I find them really annoying to have my screen dim after a minute of reading.  But again, this is situational, you have to be the judge, and the settings are available to you.

;) Except for iPhone auto dimming.   Auto dimming is controlled by  4 of the settings, in different locations on the phone that are available to you, but one is not.  So don't bother.  It's going to auto-dim on you whether you want it to or not.  Consider it a feature. ;)