Maximising battery life in mobiles

Appropos of this Upgrade (Migration) Updates I thought it might be useful to give some tips on maximising your battery lifetime. If you change your phone every year, this doesn’t really matter, but if you keep your phone for a couple of years or more, following these tips will help prolong the battery capacity.

  1. Try to charge before it gets below 30% or so - going much below this reduces the battery cycle life, keep doing it and you will throw away up to half of the charge cycles

  2. Even better don’t charge above about 75% - as the voltage on the battery gets higher, tiny imperfections are created and these reduce life by up to 75%. Yes, a battery charged to 75% can achieve 2000 charge cycles, charge it to 100% and you will get around 500 charge cycles.

  3. Charge it as slowly as you can - if you are going to charge it overnight, find the lowest power charger you can. I put mine on an old 5W iphone charger by my bed, cos it’s got 7 or 8 hours to charge so who cares how slowly it does it. If I need to charge in the day I put it on the highest power charger I can find because speed is more important then. The reason for this is that fast charging causes more internal degradation than slow charging.

There’s no need to be obsessive about it, but following these recommendations when you have chance will give you a much healthier battery over time.



Even better don’t charge above about 75%

This is probably going to end up counter-productive. The only way to stop a phone from charging above 75% is to unplug but from that point it’ll start draining the battery again right away where as when charging up to full the phone can be left plugged in and it’ll no longer drain the battery and run off the charger instead, overall reducing battery wear.

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Yes, you are exchanging up to 1500 charge cycles for the amount of time you sit on the charger above 75% charge.

But that amount of time would be the entire night for many of us who charge our phones at night, so not a negligible amount IMO.

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I leave mine on overnight, I prefer to give up the charge cycles for a longer run time. If you turn your phone off overnight however, charging to 75% and then turning it off will massively prolong battery life.

The cells they put in satellites and space craft are cycled between 75% and 30% their whole life, cos it is really hard to change them!

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Myth: Charging Your Battery Overnight Kills the Long-Term Battery Life

Unfortunately they are wrong here. You cannot ‘overcharge’ a li-ion battery with a modern charger, but the time spent between 75% charge and 100% charge is way more degrading to the battery (technically it is a cell) than at lower states of charge. The manufacturers spec the battery at 500 cycles for normal use. Follow my recommendations and you will get way more.

Trickle charge—what your battery gets when it’s connected and full—is way less detrimental to the battery’s health than a larger discharge would be.

Trickle charge a full lithium battery and it will explode. This guy doesn’t know what he’s talking about. A li-ion charger stops charging at 100% and waits for the battery to drop. It then tops it off again. Trickle charging is what old NiCd chargers did, they kept putting a tiny charge into the cell to keep it topped off.


Myth 5: Leaving your phone on 24/7 is no big deal

Most people keep their phones on all the time, and only turn their pocket-computer off when something has gone wrong. This is not a good idea. You smartphone needs to be rebooted every now and then, and not doing so is detrimental to the lifespan of your battery.

This is complete BS, where do they get these guys? Older fuel gauges needed to be charge cycled to determine how much capacity the battery has, but the battery absolutely does not need the phone to be rebooted. Poppycock.


Some devices are smart and charge to around 75% capacity and display that as “full”.

Nowadays I think the biggest battery killers are smart chargers, I deliberately do not use mine unless I absolutely have to (every few months)

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Yep charge to 50% for storage is putting the battery into the same range as I mentioned, pretty much anywhere between 30% and 75% is ok, the difference in the charge cycle life over that range is maybe 10%.

I agree with your admonition regarding obsessiveness.

I can only speak about iPhones, but I’ve had an iPhone 6 since its launch date, and plugged it into an Apple charger every night. I changed the battery only last month as it wasn’t lasting as long as I needed it to, so I reckon there’s another 4 years or so of life left in the phone.

I also have an iPhone 3G which has no battery issues.

The charger in the 3G really didn’t push the battery hard, but Li ion degrades as it sits there (more so at high states of charge) so it will die soon.

“Fun” fact: If I (Galaxy S6) try to combine these two I probably need to charge my phone every 10 minutes or so :cry:

Yes, I’m exaggerating - but only a tiny bit …


Nah! It’s like the Morris Minor of smartphones. Just keeps on and on and on…:wink:

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This all sounds very complex - I found the best answer was to buy a £200 Lenovo P2 that pairs a 5000mah battery with a 625 processor…

Because the phone is so cheap you can replace it every year unlike a £400 or £600 phone…

Agreed totally. I wish there was a way to set a charge cap on phones, that would really be the most productive option.

If you use AccuBattery on Android you can set it to make a powerful and obnoxious vibrate repeatedly once the battery hits a certain percentage of charge.

Unfortunately, that still won’t cap charge. What I mean is I leave my phone plugged in at home and at work so it’s always ready. I’d love to be able to do that, but keep charge capped to 80% (with an over-ride button of course for when I do need a full charge).

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There is functionality in Android OS to do this, however it isn’t open in the API :confused: (For good reason!)

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