Comment by pasbesoin | Hacker News Reader

Comment by pasbesoin | Hacker News Reader

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Don't know whether this fits, but here's something I'd like from the power system: Automated battery maintenance. I'm plugged in, a lot, and I forget to / blow off periodically cycling my battery. (Admittedly, maybe I'm unusual / an edge case, in this, and my thoughts here are of little general value.)

I'd like a power system that can be made to periodically and contextually select to run from battery, even while plugged in, so that the battery can be cycled in a manner that maintains its capacity.

So, when, every some weeks, I do need to run from battery, it's still in decent shape. Without my having to manually ensure this on an ongoing basis.

I doubt its' a priority for Bunnie, but what the heck, I'll throw the idea out there. When else do I have even a chance of having any input into a laptop's design?

Oh, and thank goodness for an(other) open alternative to "secure boot" (maybe nice in principle, but very potentially malicious in current execution).

Best thing for most lithium batteries is to be kept cool and neither fully charged or discharged. Many phones already try to keep the battery at about 90% or so for this reason, it might be nice if this was configurable on this laptop.

Keeping a laptop on and plugged in all the time, especially if it runs hot, is probably the fastest way to decrease its capacity beyond extremely aggressive charge/discharge cycles (normal use is probably better since the average state of charge is then lower). I've completely killed a battery in a few months when I made a habit of leaving my laptop on my bed turned on during most of the day, Now I either remove the battery or keep the laptop in sleep when it's not being used if it's being kept plugged in for extended periods.

Only what you're suggesting isn't actually battery maintenance. In fact, it will decrease the capacity of your battery (by as much as a normal drain-recharge cycle of course).

Cycling the battery will however appear to improve the capacity by recalibrating the internal circuitry. That's still somewhat useful to a user, but much less than battery maintenance would be.

PS: From what I understand this only applies to modern Li-Ion batteries, if you're using different battery technology your mileage may vary. Some battery technologies do benefit from being periodically cycled.

Maybe I'm not up to speed on the latest developments, but I currently have two laptops whose batteries have essentially been reduced to short duration UPS's.

I should be more pro-active, but I forget, or I worry that I'll discharge right before I need to be charged up. And one sits on a spare table, doing its thing all by itself, much of the time.

They tend to stay plugged in and on overnight. It would be nice if, e.g. once a week or so -- whatever's best for the battery at hand -- the power system could run a discharge /recharge cycle "in the middle of the night" or similar.

In my experience, batteries still have memories (that shrink over time and with lack of cycling), and from what I read periodic cycling is the solution.

If Bunnie can find an acceptable fuel cell option, of course I'm all for that. ;-)

P.S. I think I do at least partway understand what you're saying, that being that rechargeable batteries have a limited number of cycles and tend to loss capacity with increasing cycle count.

However, in my case, it appears to be a lack of cycling that is catching up with me well before the above does.

That's very weird: my laptops stay plugged and on 24/7 for months at a time, and the batteries still last around 2.5 hours. These are 4 year old Li-Ion batteries I'm talking about (they used to last 3 hours when they were new).

Same experience here, i kept my laptop in a socket almost every day for 2 years only bringing it out maybe once a month. The battery was as good as new until i forgot it completely uncharged for 2 weeks when it overnight reduced its 2h capability into more like 2 minutes.

Oh yeah, that kills them pretty fast. I've had the same experience with my backup cellphone and mp3 player, had to buy new batteries.

Hmm. Then maybe I'm ascribing my problem to the wrong behavior. I wonder whether I inadvertently left my problem children discharged for too long, at some point.

I've gotten reliable service out of my mobile phones, but laptop Li ion batteries continue to feel (for lack of a more consistent and rational/analytical approach, on my part) like black magic, to me.

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