Date: Fri, 20 Jan 2017 15:39:17 -0600 (CST) From: "Valeri Galtsev" <galtsev@kicp.uchicago.edu> To: "Matthias Apitz" <guru@unixarea.de>, freebsd-questions@freebsd.org Subject: Re: stop charging laptop battery when full Message-ID: <38889.128.135.52.6.1484948357.squirrel@cosmo.uchicago.edu> In-Reply-To: <20170120200826.GA2070@c720-r292778-amd64> References: <20170120171125.GA3965@c720-r292778-amd64> <20170120135008.5168cc79@riseup.net> <20170120200826.GA2070@c720-r292778-amd64>
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On Fri, January 20, 2017 2:08 pm, Matthias Apitz wrote: > El día Friday, January 20, 2017 a las 01:53:50PM -0500, Sergei > Akhmatdinov escribió: > >> On Fri, 20 Jan 2017 18:11:25 +0100 >> Matthias Apitz <guru@unixarea.de> wrote: >> > I can ask the current capacity (and other values) of the battery with: >> > [snip] >> > While charging, is there a way to stop the charging when >> > hw.acpi.battery.life reached 100 to protect the (LI-ion) battery? >> Such functionality should be provided by your battery's internal circuitry. >> Think about it, it wouldn't be safe for any consumer to buy a laptop which >> doesn't switch to DC power when the battery is full. > > I'm not sure about this. Let's assume the power provided by the charger it withdrawn "somehow" from the battery and the laptop runs only on the power > provided by the charger. The battery will now start to drain itself (due to > its internal resistor value). When it will start to charge again, and how? This whole thing in laptops is done by rather trivial electronic circuits and switches (based on CMOS power FETs (with 0.01 - 0.001 ohm closed resistance). When laptop is connected to charger (providing appropriate voltage, internal laptop circuits are fed bu voltage from charger, and are disconnected from battery. Battery is being charged or trickle charged, and after it is full, charging stops. When you disconnect charger, only then internal switches connect battery to feed internal laptop circuits. It is all quite trivial thing that is taken care of on rather modern electronics level. I do not intend to offend you, but your consideration is on a stone age level compared to what is trivially and routinely done in laptops during last almost two decades. So, I would suggest to just trust electronics engineers and act as dumb person when using laptop: plug it into AC when you have that, or use it on battery when there is no AC around. Laptop designers do expect laptop user act exactly as dumb person. Whatever needs to be done for keeping battery ready for use without abusing it is taken care of by laptop internal circuits. I hope, this helps. Valeri > > And why all the hints say: Once fully charged, disconnect the laptop from charger? > > Will it lead to some endless charge/discharge cycle? > > I was asking for some method to disconnect the laptop completely from the charger, either internally or, for example, by some external device, receiving the signal via Wifi and cutting the charger from the outlet. > > matthias > > -- > Matthias Apitz, ✉ guru@unixarea.de, ⌂ http://www.unixarea.de/ ☎ +49-176-38902045 > "Wo ist der antiimperialistische Schutzwall, wenn man ihn braucht? US-Panzertransport durch ex-DDR" > "Where is the anti-imperialistic wall, if it's needed? Transport of US-tanks through the ex-GDR" > https://deutsch.rt.com/kurzclips/45282-us-panzertransporte-durch-ex-ddr/ _______________________________________________ > freebsd-questions@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to > "freebsd-questions-unsubscribe@freebsd.org" ++++++++++++++++++++++++++++++++++++++++ Valeri Galtsev Sr System Administrator Department of Astronomy and Astrophysics Kavli Institute for Cosmological Physics University of Chicago Phone: 773-702-4247 ++++++++++++++++++++++++++++++++++++++++
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