Care and Feeding of Laptop Batteries

[cavuman1]

Cavuwoman and I recently procured a new Acer Aspire laptop. It's a pretty nice machine with a 3.5 Ghz four-core CPU, 12 GB RAM, a 1 TB SSD, and a 1080 HD 15" screen. It's running Windows 11 which takes some getting used to and a modicum of profanity.

My question involves a dilemma set forth by the manufacturer. On p.56, the owner's manual stipulates: Conditioning a new battery pack
Before you use a battery pack for the first time, there is a conditioning process that you should follow:
1. Connect the AC adapter and fully charge the battery.
2. Turn on the computer and complete setting up the operating system.
3. Disconnect the AC adapter.
4. Operate the computer using battery power.
5. Fully deplete the battery until the battery-low warning appears.
6. Reconnect the AC adapter and fully charge the battery again.
Follow these steps again until the battery has been charged and discharged three times.

Battery pack
Use this conditioning process for all new batteries, or if a battery hasn't been used for a long time.The battery conditioning process ensures your battery accepts the maximum possible charge. Failure to follow this procedure will prevent you from obtaining the maximum battery charge, and will also shorten the effective lifespan of the battery. In addition, the useful lifespan of the battery is adversely
affected by the following usage patterns:
• Using the computer on constant AC power.
• Not discharging and recharging the battery to its extremes, as described above.
• Frequent use; the more you use the battery, the faster it will reach the end of its effective life. An embedded battery has a life span of more than 1,000 charge/discharge cycles."

DEEP BREATH... and then on the same page:
Optimizing battery Life
Optimizing battery life helps you get the most out of battery operation, prolonging the charge/recharge cycle and improving recharging efficiency. You are advised to follow the suggestions set out below:
• Use AC power whenever possible, reserving battery for mobile use.
56 - Battery pack
Use this conditioning process for all new batteries, or if a battery hasn't been used for a long time.
The battery conditioning process ensures your battery accepts the maximum possible charge. Failure to follow this procedure will prevent you from obtaining the maximum battery charge, and will also shorten the effective lifespan of the battery. In addition, the useful lifespan of the battery is adversely affected by the following usage patterns:
• Using the computer on constant AC power.
• Not discharging and recharging the battery to its extremes, as described above.
• Frequent use; the more you use the battery, the faster it will reach the end of its effective life. An embedded battery has a life span of more than 1,000 charge/discharge cycles.
Optimizing battery life
Optimizing battery life helps you get the most out of battery operation, prolonging the charge/recharge cycle and improving recharging efficiency. You are advised to follow the suggestions set out below:
• Use AC power whenever possible, reserving battery for mobile use.
• Remove accessories that are not being used (e.g. a USB disk drive), as they can continue to draw power.
• Excessive recharging decreases the battery life.

Thus I am confronted by this conundrum: should the batteries be subjected to a deep discharge - deep recharge scenario for the life of the system, or should we leave the AC power active at all times. The manual espouses both methodologies! AH! The inscrutable oriental mind! I do have some reluctance to charge Li batteries at night - being awakened in the midst of a conflagration isn't my idea of a good night's sleep. Should a computer be left on 24/7, or should the device be de-energized on occasion?

What advice do you PPRuNe experts have to offer? You have our gratitude in advance as well as that of SNARFY, which is our computer's name,

- Ed

[MechEngr]

It's Acer. What did you expect? The main problem battery packs suffer from is that some cell won't keep up with the rest. Unless the pack has a forced balancing system then when that cell gets low the other cells will back-drive current through it doing some damage and lowering the life. There is usually some battery management chip that is looking for current-in vs current out vs voltage and it is adapting the usage reporting on that basis. I had a battery that was reported as 100% charged and offered less than 5 minutes before the computer could not run.

[aerobelly]

I too have an Acer Inspire less than a year old with similar spec. I junked Winblows and it is now on Linux Mint 20.2 -- no problems with the original installation of Mint 20.0 nor the successive upgrades to 20.1 and 20.2 (think Service Packs in M$ terms (do they still do that?)) -- at about 15 minutes each.

I reckon it will be less than three years (two maybe) before I fill the keyboard with orange juice (most recent f-up, there have been other fluids) and need a new laptop so I treat it as an indoor lapdog and take it outside and off-mains every month to give its battery a bit of a discharge. Should be OK in theory.

Having sworn off HP after being a good business and personal customer for many years, and recently Dell too, I find the Acer good value for money. If it lasts me at home for three years that will be a 300% improvement on the average life of a business laptop IME.

'a

[Uplinker]

I cannot speak for the OP's equipment, but my own experience with Apple is that keeping the AC power on when using the iPad does not seem to compromise the battery, and in fact makes it lasts a lot longer if I ever do then take it off charge, than if I unplug it as soon as it reports 100% full.

This iPad is quite old now, and it started "dying early", when the battery was still showing 20-26% capacity. I solved this problem by using a small capacity charger rather than the large capacity one, and the same iPad with the same usage pattern, now lasts down until the battery shows 1% charge.

I think the reason is that the internal resistance of the battery gradually increases as it ages, and if a high capacity charger is used the higher internal resistance can make the battery charge state appear higher than it really is; at which point the iPad charging monitor switches off the charging. This actually leaves the battery only, say, 75% charged, but I found that using the smaller capacity charger - slower for longer - gets the battery much closer to a full charge. Then leaving the charger connected when at my desk gets it even closer to properly full.

Concerns about unattended lithium chargers could be valid. I have never had an issue, but I only use genuine Apple chargers and gear.

This battery must have been through well over 1,000 cycles, and although it will only last a couple of hours on continuous battery-only use, it is still soldiering on very well.

[Thirsty]

I suspect that it may be to do with the laptop charging system learning the upper and lower limits it has to play with. Rechargeable batteries have vastly improved over the years, the old universal rule of thumb of approximately 500 charge/discharge cycles has rapidly risen to where it is today. With more modern chargers having a two way conversation with the unit they are powering to work out how much current and voltage to supply, I suspect that the charger is throttled down when not needed, and boosted when required as well. The memory effect of NiCad batteries is a distant past with new battery technologies emerging. Think of your battery as an UPS to jump in when power is suddenly lost and you should be fine for many years plugged into the mains.

As a general comment on Acer equipment. Having worked with thousands of them over the years, I have observed if one purchases a unit with a one year warranty, then it will work reliably for one year and ONE day, and then suddenly fail. Get one with a three year warranty, and it will fail after three years and ONE day. They are built to very tight specifications, and due to volume, the engineering can be a work of art, where even the case design is such that where a reduction of a screw or two worth a penny can be saved, over the course of a production run of a few million units, massive savings can be made. Far more than with any other item of equipment I have seen, computing or not, you are getting what you paid for, not one penny less or one penny more.

With the recent breathless news missives of superconductors operating at room temperatures (excluding the entire northern hemisphere with the excessive heat due to climate change will stop them from working), within a few short years laptops will be powering themselves without any external connections, the true perpetual motion machines my uncle dreamily told us about, all those decades ago, as he drew a water wheel at the outside of a boat, being turned by a constant flow of water from a spout coming from a hole in the middle of the boat that produced a geyser that flowed over the top of the wheel, thus turning it for ever from the constant flow of water. When we built a little boat and waterwheel, tried it in the bathtub, the geyser never went higher than the outside level of water the boat was sitting in, this destroying that theory, took away my childhood innocence of wonder at marvellous things, and turned me into a sly old science cynic.

Don't get me started on fusion power! The technology 'just around the corner', driven by laser beams and massive magnets trapping the super-hot plasma into a torus, to be released in 'a year or two', these promises being rolled out at excited investor forums for the last thirty or forty years at least. Go to sleep with one of those ticking away and see if you awake in terror at what could happen. BOOM!

Just a little ditty that is ironic in light of climate change warriors these days:
Perpetual Motion (https://upload.wikimedia.org/wikipedia/commons/transcoded/3/3a/Something_for_nothing_%281940%29.ogv/Something_for_nothing_%281940%29.ogv.240p.webm)

[cavuman1]

Thank you all for your informative answers! I think I shall comply with the manufacturer's recommendation - three deep discharge/recharge cycles, then I'll keep the computer plugged in, though the latter goes against Acer's instructions.

Now for my second question: Should a computer be left on 24/7, or should the device be de-energized on occasion?

I look forward to your replies!

- Ed

[netstruggler]

Thank you all for your informative answers! I think I shall comply with the manufacturer's recommendation - three deep discharge/recharge cycles, then I'll keep the computer plugged in, though the latter goes against Acer's instructions.

Now for my second question: Should a computer be left on 24/7, or should the device be de-energized on occasion?

I look forward to your replies!

- Ed

I'm quite old school.

At the end of the day I log out and shutdown the laptop and pull the power lead out of the laptop.

I don't think pulling out the lead serves any useful purpose but I would recommend logging out. A few years ago I would have recommended shutting down as well but Windows has improved a lot since then and seems to run happily for months on end without needing a reboot, so letting it go to 'sleep' is probably fine. As I said, I do shutdown though.

Note that, if you do not disable Windows 'Fast Start' then shutting down the computer will not log you out, even though it warns you that it's going to. This means that if the computer is used by multiple people who don't log out then after a while they will all be logged in all the time. I think this is a bad thing. It means when you're using the computer it can be running other user's background tasks, and it's a bigger risk if one of the accounts gets compromised by some unfriendly software.

Regarding battery life - I've enabled my laptop's 'always on mains' feature which means the battery only charges to 80% full, and once or twice a week I leave the power lead out for a few hours while I'm using it so it discharges down to 30% or so (unless I forgot to plug it in again it which case it goes down to 0% and turns off).

Those instructions you quoted are for NiCad or NiMh rechargeable cells which suffer from a 'Memory' effect if they don't go through a full discharge cycle every now and then. A few years ago it was quite common to find that a laptop that had been run entirely on mains for a couple of years would then only run for a few minutes on its battery. I would hope that things have improved a bit now.

I would follow the instructions as best you can without inconveniencing yourself. I think if you do 20% of what they say you'll get 80% of the benefit.

HTH

N

[NutLoose]

Its all about Battery memory, the battery will not fully charge after a while if not run down, read

https://en.wikipedia.org/wiki/Memory_effect

I have a Sony Xperia One mobile and I charge it as and when, it sometimes pops up it needs to do a deep cycle charge and automatically carries it out, it takes longer but keeps the battery healthy.

[jimjim1]

Its all about Battery memory, ...
https://en.wikipedia.org/wiki/Memory_effect
.

That article opens with — "Memory effect, also known as battery effect, lazy battery effect, or battery memory, is an effect observed in nickel-cadmium (https://en.wikipedia.org/wiki/Nickel-cadmium) rechargeable batteries (https://en.wikipedia.org/wiki/Rechargeable_battery) that causes them to hold less charge"

The OP's laptop will NOT HAVE a NiCad battery and so it is irrelevant,

[MechEngr]

It's a different problem than NiCds - in laptops there is a chip that constantly tries to estimate "state of charge" and it uses voltage and current in and current out to make that estimate. If the voltage remains relatively constant, as it does when kept charged then any errors in current in vs current out accumulate and the chip will tend to report the wrong battery life. Running the battery down to the minimum voltage resets the charge monitoring data.

There is a claim of "memory effect" for other cells but any series battery pack that doesn't have active voltage balancing can have problems. At some point one cell will be the slacker. It will drop in voltage a bit more than the others and won't get fully charged with the rest. The remainder might end up overcharged, with a rapid drop-off that looks like "memory" but an examination will show one or more cells is suffering.

I saw a bunch of replaceable NiMH AAs used in a camera by some coworkers. The camera would die after short use from a "full charge" and they'd slam them all back on the dumb charger. They came off hot to the touch. One of the cells was under 0.5 V out of a possible 1.2V. Tossed that one and grab a spare and suddenly the camera works again. Yay! In laptops it's tougher to detect as there is usually a sensor to keep the temp of the pack down instead of bursting into flames.

[Shaman]

This site helped me:

https://www.laptopbatteryexpress.com/Laptop-battery-FAQs-s/11929.htm