Best way to use battery?

[donawalt]

Best way to use battery

Hi all, I have an iPhone 6s and love it.

I have a question on how best to use the phone when sitting at a desk/near a plug.

I know that any given battery has so many complete charge cycles in its life - and over the course of that life a full recharge drops.

So when I am able to plug it in, should I - does that bypass use of the battery entirely and prolong its life? Or is it better to think of it as a constant slight drain-recharge activity - so using a phone 12 hours then recharging is the same, from a battery life/cycles used perspective, as running on battery then recharging at the end of the 12 hours?

Thanks!

 

[doogald]

Re: Best way to use battery

So when I am able to plug it in, should I - does that bypass use of the battery entirely and prolong its life?

It does not bypass the battery - the phone always runs off the battery, and the charger will either charge the battery or start trickle charging if the battery is close to full charge.

Or is it better to think of it as a constant slight drain-recharge activity - so using a phone 12 hours then recharging is the same, from a battery life/cycles used perspective, as running on battery then recharging at the end of the 12 hours?

Yes, exactly, A battery charge cycle is the amount of charge used to full charge the battery from 0 to 100. If you drain the battery to 75% and charge 4 times (25% each time), that's one charge cycle. Drain the battery to 50% and charge to 100% twice is also one full charge cycle.

The lithium ion batteries in iPhones work best when you give a lot of small charges than a smaller number of large charges, though. As I understand it, your battery would last longest if you regularly charged from 60% and stopped at 80% (because as the battery nears full charge, the cells start to heat, which degrades the battery more).

But, keeping the phone plugged in at 100% really is fine - the phone will stop the charge and start to trickle when it starts dropping again.

Battery University is a great site, and though it deals mostly with laptop batteries, I think it's still relevant to phones. See How to Prolong Lithium-based Batteries - Battery University

A few quotes from that site:

Similar to a mechanical device that wears out faster with heavy use, so also does the depth of discharge (DoD) determine the cycle count. The shorter the discharge (low DoD), the longer the battery will last. If at all possible, avoid full discharges and charge the battery more often between uses. Partial discharge on Li-ion is fine. There is no memory and the battery does not need periodic full discharge cycles to prolong life. The exception may be a periodic calibration of the fuel gauge on a smart battery or intelligent device.

The question is asked, “Should I disconnect my laptop from the power grid when not in use?” Under normal circumstances this should not be necessary because charging stops when the Li-ion battery is full. A topping charge is only applied when the battery voltage drops to a certain level. Most users do not remove the AC power, and this practice is safe.

 

[Ledsteplin]

Re: Best way to use battery

It does not bypass the battery - the phone always runs off the battery, and the charger will either charge the battery or start trickle charging if the battery is close to full charge.



Yes, exactly, A battery charge cycle is the amount of charge used to full charge the battery from 0 to 100. If you drain the battery to 75% and charge 4 times (25% each time), that's one charge cycle. Drain the battery to 50% and charge to 100% twice is also one full charge cycle.

The lithium ion batteries in iPhones work best when you give a lot of small charges than a smaller number of large charges, though. As I understand it, your battery would last longest if you regularly charged from 60% and stopped at 80% (because as the battery nears full charge, the cells start to heat, which degrades the battery more).

But, keeping the phone plugged in at 100% really is fine - the phone will stop the charge and start to trickle when it starts dropping again.

Battery University is a great site, and though it deals mostly with laptop batteries, I think it's still relevant to phones. See How to Prolong Lithium-based Batteries - Battery University

A few quotes from that site:

When you're plugged in to a power source, the iPhone will not use the battery unless for some reason you are using more power than the charging source can provide.
That said, it's not good to use the iPhone with it plugged in for long periods of time beyond the charge time.

 

[nnahorski]

Re: Best way to use battery

Everybody has their own recommendations for how best to use, condition, and preserve their iPhone battery.

In years with an iPhone, I've always just used it and plugged it in when I need to. I ply in to charge overnight every night, and leave it on the charger until the morning. I top off the battery at work or in my car when I need to. YMMV, but I've never had an issue with any iPhone batted treating it this way.

My advice is to just use the phone and try not to worry so much about the battery

 

[donawalt]

Re: Best way to use battery

Thanks for the comments all!

 

[timja]

Re: Best way to use battery

I find this very useful too, thank you.