Extending lithium battery lifespan - Page 1
Forum section: electronics / general

author: Connecteur
author_rank: Frequent Contributor
timestamp: July 17, 2021, 03:37:13 pm
content: I have very little electronic expertise, but I believe the lifespan of lithium cells can be greatly extended by undercharging. Conversely, I believe that overcharging shortens their lifespan. I have replaced 12V batteries with banks of 4 lithium cells in series. This charges each cell to 3V, well below the nominal full charge of 4.2V. I expect such a battery of cells will last many years.I had the Battery in my Samsung S9+ blow up before it was 2 years old. What I mean is that the battery expanded and pushed the backplate off. I found out it's because the battery gets charged to 4.4 volts, which increased capacity marginally, but reduces battery longevity considerably.After some research, I learned that charging a lithium cell to 85% will extend it's lifespan by 210%. The small decrease in capacity is little concern to me. I have 2 Samsung tablets with the same operating system as the phone, and one of the options is to charge the battery to only 85% to extend battery longevity. There is no such option on the Samsung phone. Why not? It's easy to assume that it's to make the phone fail after a year so that you'll buy a new one.There is no app that will stop the phone from fully charging to 100% (4.4 V) but there is an app that will sound an alarm when it reaches a predetermined level. I've been using it since I had to pay a hundred bucks for a new phone battery to be installed.Am I on the right track?

author: tunk
author_rank: Super Contributor
timestamp: July 17, 2021, 04:07:17 pm
content: For most li-ion/li-po cell, 3.0V is fully discharged.And that overdischarging them is detrimental to their life.I guess you could charge them to 4.0V and discharge themto 3.2V.

author: Siwastaja
author_rank: Super Contributor
timestamp: July 17, 2021, 04:59:23 pm
content: Not on a very good track so far but you'll get there...First, lithium batteries as of today are non-rechargeable. There are chargeable lithium cells but they are niche / development / lab products and unusable in real world so far.So we have toassumeyou are talking about lithium ion cells, completely different animal.Then, "charging to 3.0V" would not make sense with the most prevalent LCO, NCA, NMC, LMO, LFP chemistries since on all of them, 3.0V is completely discharged. So maybe you are discussing lithium titanate oxide cells such as Altair Nano? But here, full charge is at 2.9V so 3.0V is already slightly overcharged. So this 3.0V thing just doesn't make any sense.Assuming you are indeed discussing the most typical li-ion cells of today, that would be NCA or NMC, idea of derating capacity to 85% bringing you 210% extra lifespan is iffy. Yes, if you consider high-current cycling up to 100%, that could be a case in some carefully crafted test, but you could get similar lifespan improvement by just charging more slowly from 85% to 100%. Calendar fading at 100% and 85% is possibly the same; it depends, some cells get improvements, some others don't. Usually you start seeing significant results below some 70%.It's possible the other Samsung phone doesn't have the 85% option because on that cell chemistry, there just is no difference, or they have made other "automatic" improvements (like finding out by testing what I did years ago; just limit current a tad near 4.2V!) Another possibility is, thereisdifference but they want to play the planned obsolescence game.I don't believe any tablet uses chemistry where 100% charge is at 4.4V, but I might be wrong.

author: GigaJoe
author_rank: Frequent Contributor
timestamp: July 17, 2021, 05:19:15 pm
content: percentage of charge indicated on a device in direct correlation with impedance of battery. fully charge level usually depend on battery chemistry and can be from 3.70 to 4.35V . it probably 30+ variation of chemistry compound in overall , only few in mass production. measure precise fraction are important, like 4.31V still has a percentage of let say 3.35V top level. (it means need at least 4.XXX on measurement device display, not 4.X - too uncerain )usually it a single chip that responsible for charging , type and top voltage correlated to battery chemistry.it possible that chip out of spec tolerance, or it shifted in time, so charging process are incorrect. ( we deal with 4.XX precision)longevity of battery directly depend on charging cycles , charge \ discharge level, usage temperature.amount of charging cycles usually limited by 300-400 full cycles , till battery lost 30-40% of capacity. with fraction of cycles , let say from 30% to 80% it can be even extended to 1000charging current usually play the most role in longevity, so would be advisable do not use fast charging , or disable it.but it direct correlation with battery capacity. so large tablets due to large battery capacity , and surface much more tolerable to the high current.temperature also factor that can be overlooked, due to charging cycle it produce a heat that need to dissipate , do device pass the heat over the shell to the surface table cooling itself, but if it in enclosure it more difficult. so internal temperature are rising.personally I.m use 5v 0.5A charger over night (or 5V 1A charger with long cheap cables) my S8 usually shows 4 hours to full charge. so current and temperature artificially limited. I don't bother to charge up to 90% - not big deal . but in extremely caution do not discharge below 20%, usually 30% - set to charge.my tablet has magnet connector, it also limit current

author: duckduck
author_rank: Frequent Contributor
timestamp: July 17, 2021, 11:55:25 pm
content: I used to set a timer for 30 minutes or whatever on my phone to beep to remind me to pull the phone off of the charger. I bought one of these and it works well. It's a little annoying to use, but I can set it and forget it. Search for "USB timer" or similar. I thought of making my own thing, but Shenzhen does it cheaper...

author: Siwastaja
author_rank: Super Contributor
timestamp: July 18, 2021, 07:26:52 am
content: I don't believe a $11.49 device for cutting charging early ever pays back for itself in extended battery life. But I might be wrong, of course.

author: westfw
author_rank: Super Contributor
timestamp: July 20, 2021, 09:32:00 am
content: With phones that have essentially non-replaceable batteries costing about $300+ (Call it about $100/year of useful life, if you’re lucky), it’d only take an extra month or two of battery life extension to pay for you $12 gadget.

author: Connecteur
author_rank: Frequent Contributor
timestamp: October 11, 2021, 04:05:00 pm
content: I just use a battery charge alarm app to tell me when the battery reaches a certain level. There are apps that will stop charging at a preset level, but they require rooting the phone. I use the same one on my phone as on my Chromebook:https://play.google.com/store/search?q=battery%20alarm&c=apps&hl=en_CA&gl=USTHis is the one I use:https://play.google.com/store/apps/details?id=simple.batttery.alarm&hl=en_CA&gl=US

author: RoadRunner
author_rank: Frequent Contributor
timestamp: October 12, 2021, 08:46:36 am
content: Sony Xperia phones have a special mode "Battery care" it charges battery really slow. Suppose to be used over night. In older devices it auto detect when you regularly plug in your phone for charge and when you regularly disconnect. New phone have options to always enable or auto detect. I do not know if other device do this as well.

author: tggzzz
author_rank: Super Contributor
timestamp: October 12, 2021, 09:02:17 am
content: I have a 10yo Samsung notebook with a battery that is still very useable.The key point is a BIOS setting that stops charging at 80% capacity.

author: not1xor1
author_rank: Frequent Contributor
timestamp: October 12, 2021, 09:33:20 am
content: Quote from: Connecteur on July 17, 2021, 03:37:13 pmAFAIK to make Li-ion batteries last as long as possible you should keep them within 40% and 60% of full charge. The corresponding voltage depends on the kind of battery. A slow charge (< 0.5C) also helps a lot as avoids/reduces metallic lithium deposition.

author: deadlylover
author_rank: Frequent Contributor
timestamp: October 12, 2021, 03:39:17 pm
content: I use a smart plug and Siri automation to turn on/off a charger automatically (it can trigger on battery percentages). I stop phone charging at 60% and iPad charging at 50%. I'm basically always home so I only charge to full if I'm on travel or if I need to go out for the whole day.Reported values are from coconut battery:iPhone XS Max = 597 cycles, 101% health (34 months old, no change from 565 cycles @ 32 months) I won the battery lottery with this phone.iPad Air 2020 = 193 cycles, 98% health (8 months old, no change from 142 cycles @ 5 months)As another fun data point, my Mum's phone without any battery care (albeit a very light user as shown from the cycle count):iPhone XS Max = 299 cycles, 95% battery health (33 months old)My poor old iPad Air 2 without any battery care shows 824 cycles, 60% health, 83 months old. Anywhere below say 20-30% and it will shut down if it does anything stressful so it's a PDF viewer now.

author: Connecteur
author_rank: Frequent Contributor
timestamp: October 12, 2021, 04:55:44 pm
content: I have two Samsung tablets, which I believe use the same version of Android as my phone. Both tablets have the option of charging to 85% to preserve battery life, but the phone has no such option.Leads me to believe that Samsung wants us to replace our phones every 1-2 years, but keep our tablets for much longer.

author: james_s
author_rank: Super Contributor
timestamp: October 12, 2021, 05:07:57 pm
content: Seems like I read some military applications charge li-ion batteries to 4.0V to extend their life. My Lenovo laptop has a mode that charges them to 87%, which I've always had enabled unless I need maximum run time. So far so good, I think it was 2015 when I bought it and I still can use it all day on a charge.

author: Connecteur
author_rank: Frequent Contributor
timestamp: October 12, 2021, 05:40:34 pm
content: Quote from: james_s on October 12, 2021, 05:07:57 pmI believe the Prius charges the lithium ion battery to 70% to preserve battery longevity.2012 models are still going strong.

author: james_s
author_rank: Super Contributor
timestamp: October 13, 2021, 01:51:39 am
content: Quote from: Connecteur on October 12, 2021, 05:40:34 pmI have no experience with the Li-ion models but I'm confident that Toyota knows what they're doing. We got 19 years and over 140k miles out of the original NiMH battery in my partner's Prius before it finally failed. $2k for a new battery and the car drives like new, it has far surpassed my expectations for reliability.