# How to maximize the life of a phone battery **URL:** \ **Category:** Factual Questions\ **Created:** [July 16, 2023, 2:44pm UTC](https://boards.straightdope.com/t/how-to-maximize-the-life-of-a-phone-battery/987113 "2023-07-16T14:44:25Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [July 16, 2023, 2:44pm UTC](https://boards.straightdope.com/t/how-to-maximize-the-life-of-a-phone-battery/987113/1 "2023-07-16T14:44:25Z")
I am not talking about how long a charge lasts, but how long the battery lasts. Should top it off every night to 100%, no matter what % is left? Should I let it get down to 30% or lower before I charge it? Should I leave it in the charger once it reaches 100% or should I unplug it immediately? Advice for battery optimization has changed so much over the years I’ve no idea what the latest wisdom is. ---
**Author:** ![J-P\_L](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/j-p_l/32/3156_2.png) [@J-P\_L](https://boards.straightdope.com/u/J-P_L)\ **Post date:** [July 16, 2023, 3:32pm UTC](https://boards.straightdope.com/t/how-to-maximize-the-life-of-a-phone-battery/987113/2 "2023-07-16T15:32:08Z")
Newer Samsung phones have a setting called “Battery Protect” that if selected will limit charging to 85%. ---
**Author:** ![DCnDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dcndc/32/2842_2.png) [@DCnDC](https://boards.straightdope.com/u/DCnDC)\ **Post date:** [July 16, 2023, 3:37pm UTC](https://boards.straightdope.com/t/how-to-maximize-the-life-of-a-phone-battery/987113/3 "2023-07-16T15:37:00Z")
The general rule is still to try to keep it anywhere between 20-80%. ---
**Author:** ![Common\_Tater](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/common_tater/32/13846_2.png) [@Common\_Tater](https://boards.straightdope.com/u/Common_Tater)\ **Post date:** [July 16, 2023, 4:06pm UTC](https://boards.straightdope.com/t/how-to-maximize-the-life-of-a-phone-battery/987113/4 "2023-07-16T16:06:35Z")
Generally speaking, I think the idea is to avoid high temperatures. Years ago I noticed a smartphone in navigation mode, constantly searching for a signal on the road would start to go Chernobyl. High temperatures can cause swelling or bloating of the battery cells and a permanent loss of capacity. Still, there are only a finite number of charge/re-charge cycles for any battery before it is time for replacement. ---
**Author:** ![Limmin](https://avatars.discourse-cdn.com/v4/letter/l/f04885/32.png) [@Limmin](https://boards.straightdope.com/u/Limmin)\ **Post date:** [July 16, 2023, 4:18pm UTC](https://boards.straightdope.com/t/how-to-maximize-the-life-of-a-phone-battery/987113/5 "2023-07-16T16:18:41Z")
I’d try to discharge the battery less, I prefer keeping the battery above 50%. Another general rule is that the less the battery is discharged within one cycle, the more cycles you can go. [https://www.sciencedirect.com/topics/engineering/cycle-life](https://www.sciencedirect.com/topics/engineering/cycle-life) ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [July 16, 2023, 5:27pm UTC](https://boards.straightdope.com/t/how-to-maximize-the-life-of-a-phone-battery/987113/6 "2023-07-16T17:27:02Z")
> [@J-P\_L](#): > > Newer Samsung phones have a setting called “Battery Protect” that if selected will limit charging to 85%. I hadn’t heard of this before, so I went looking for information and found this: > **[Should I enable Protect Battery to limit the maximum battery charge to 85% on...](https://gadgetguideonline.com/s22/protect-battery-limit-maximum-charge-85/)** > > The guide explains how the Protect Battery work on Samsung phones, how to enable it to limit maximum charge to 85%%, the pros & cons of enabling Protect Battery. It seems to confirm what @DCnDC said, saying that charging puts the most strain on the battery when it is nearly full or nearly empty. ---
**Author:** ![The\_Librarian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/the_librarian/32/402_2.png) [@The\_Librarian](https://boards.straightdope.com/u/The_Librarian)\ **Post date:** [July 16, 2023, 5:47pm UTC](https://boards.straightdope.com/t/how-to-maximize-the-life-of-a-phone-battery/987113/7 "2023-07-16T17:47:18Z")
I was wondering the same thing, so I found many of the same advice. As an extra data point my car also starts whining when it is below 20% or if I want to charge above 80%. This is of course for li-ion batteries, to get the most out of lead batteries of older ni-ca batteries the best practices are different.