Any tips on protecting battery usage when plugged in 99% of the time?

[br0adband]

Just figured I'd ask this and be done with it. I recently got a ThinkPad W541 in near-mint condition, whoever bought it in Sept 2015 hardly used it: the SSD had only 227 hours of usage on it when I first tested it out with the buyer face-to-face and I knew I had found a great deal. No issues with it, it's even still under warranty for about 110 more days (as of the time I'm making this post) and I do plan to extend that for at least another year since it's a possibility. The original factory battery has 100% capacity on it as well, only 39 cycles from what power manager is telling me but my concern is to make the battery last and survive as long as possible.

I'm rarely actually mobile, to be honest, and the laptop is plugged in about 99% of the time. Yes on occasion I might go to a local Steak & Shake which is within walking distance and just sit there and work on things while having a meal but again that's pretty infrequent, maybe once or twice a month for 2 hours max I'm running on battery.

So, the basic question is since I'm on AC so much, and knowing that the battery circuit stops charging at the 100% point - I'm still trying to figure out how best to adjust the charging parameters of power manager; I haven't owned a ThinkPad in a long long time so I want this one to last as long as possible. I suppose the question I'm asking is: what would be considered "best practices" for someone with such a laptop, wanting to preserve and protect the battery from any problems, knowing it'll be plugged into the charger ~99% of the time? Is it wise to take it off the charger a few times a month and then allow it to cycle down to say 5-10% and then charge it back up?

I don't have any issues getting a new battery if needed but since this one - with a manufacturing date of July 2015 so it's the factory one - is in such good shape at the moment I'd just like to keep it that way for the future even in spite of me being plugged in so much.

Thanks for any information that might be provided. So far this has been an outstanding machine and aside from the chiclet keyboard which I can't stand but I'm tolerating as best I can everything has been great. I plan to get a docking station if I can find one at a decent price soon so I can switch back to a proper full size keyboard or even maybe one of those funky ThinkPad models that's been converted to a USB model, those are pretty awesome considering I do favor the old "proper" ThinkPad keyboards pre-*30 series.

Have fun, always...

ps
One other question: can anyone identify the functionality of these keys, the F11 and F12, on this W541? I have no clue and the user guide has been of no use, I can't find any info about these or the icons shown on the keys either, it's a total mystery to me so far:

https://s9.postimg.cc/yk9kusyxr/Think_Pad_Keys.png

Admin warning:
picture(s) WAY too big, tags removed. Please read the Forum Rules, especially Section 5: https://forum.thinkpads.com/viewtopic.php?f=16&t=14339

[dr_st]

Best practices vary between users, and not everyone will agree on what they are.

Lenovo's software allows you to set custom charging thresholds (for the battery to start charging at X% and stop at Y%). If you keep the battery at a charge level lower than 100%, it will degrade less. Some say that 40-50% is optimal, but then you don't have enough battery when you actually want to use it. So I would suggest to set the charge stop threshold at 80-90% and the start threshold about 10% under that, and forget about it.

[ZaZ]

can anyone identify the functionality of these keys, the F11 and F12, on this W541?

Page 21 of the W541 user guide will reveal all.

[theterminator93]

Dr_st pretty much sums it up. Depending on who you talk to, everyone will give a different opinion.

The facts are that Li-ion batteries degrade over time much less when they aren't stored at a full charge and are kept cool. Higher temperatures is more degrading than higher charge levels. There was a nice chart demonstrating this at one point on WIkipedia, but it was long removed for some reason. I saved the article for posterity:

Storage Temperature 40% Charge 100% Charge
0 °C (32 °F) 2% loss after 1 year 6% loss after 1 year
25 °C (77 °F) 4% loss after 1 year 20% loss after 1 year
40 °C (104 °F) 15% loss after 1 year 35% loss after 1 year
60 °C (140 °F) 25% loss after 1 year 40% loss after 3 months
Source: BatteryUniversity.com[16]

Truthfully that is probably not as accurate with newer formulations in modern Li-ion batteries, but you understand the gist... high capacity is nowhere near as detrimental to long term capacity as high temps.

Back when I got my T61p (new) I set the battery charge thresholds to start charging under 40% and stop at 70%. If I anticipated needing more battery life, I'd just go into Power Manager and tell it to fully charge a day or few hours in advance, then set it back when I was done. Ten years later that original Sanyo battery still holds a couple hours of charge on that machine.

The newer versions of Power Manager will automatically change charge thresholds in the background as it learns your usage patterns. "Maximum runtime mode" will use 100% of the battery's available capacity, and "Maximum lifespan mode" will stop charging at 90% or so of the actual capacity, while showing at 100% charge.

On that topic, Sanyo vs. Sony vs. Panasonic is less relevant with the newer models since Sanyo bought Panasonic. They're all much pretty good at long-term longevity than they (Sanyo!) were (was) 10 years ago.

Edit: Read the updated article on prolonging Li-ion service life here: http://batteryuniversity.com/learn/arti ... _batteries

[br0adband]

Thank you all for the info, and again considering this battery was manufactured on July 9 2015 and it's just a few months shy of being 3 years old, I'm happy to report it's still showing basically the full capacity even after the short period of time I've owned it. I've run it down to about 9% once, just yesterday I allowed it to run down to 18% then plugged in and I'm still extremely happy to see this in Power Manager so I'm sure I'm good to go for the long haul - I did the full 100% charge yesterday but I'm going to run it down to 50% here in a bit and then let it charge back up to 75% and then hold at that point for the future: