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72

Nope, it should be fine. Laptops are designed to switch between battery and mains power. Stuff to watch out for? Tripping hazards. While barrel connectors are fairly robust, they've been known to fail — especially with a sideways force. Unplugging the power connector totally would mitigate both this and tripping risk. While there are special mechanisms for ...


64

Yes, it is absolutely safe to charge a device with a charger that has more current capacity than needed. Ohm's law tells us the relation between current, voltage, and resistance: I = V / R (current = voltage / resistance) Since the voltage is held constant (5V), the only factor that determines current draw is the load (another term ...


42

This really depends on the inner workings of the individual adapter. A cheap one might just continue running, while a more elaborate one will turn itself (almost completely) off. For example, Nintendo's power adapters for the Wii U and 3DS are basically dormant when not connected (the current is simply too low for measurement; at least in my case). If you're ...


25

Your brother-in-law has an outdated view of how rechargeable batteries work. Older laptops used NiCd batteries were susceptible to the memory effect. Their maximum charge could be reduced if they were repeatedly partially discharged and then charged. There were all sorts of attempts to mitigate this, including waiting until the battery was discharged before ...


20

All power adapters have some parasitic loss inside them such as: switching loss from hysteresis of the transformer switching loss from transistors (leakage current) Partial conduction from movs/x/y caps (age/wear) However like Mario has advised, they do ramp up/down subject to demand, but only for smart chargers like your laptop and not so much for basic ...


19

I have used a piece of receipt from shop. It is thin enough to fit. The goal is to close middle connector. It is possible to close also 2 connectors at the left or at the right. For example close 3rd, 4th and 5th connectors, but leave free 1st and 2nd or conversely.


17

This is now supported through a tool that edits charge level in SMC: https://github.com/davidwernhart/AlDente I have it installed on my Macbook 12 (2016 model) it's sitting at 70% plugged in.


16

Generally no. Most phones will only charge at 500mA (about half of what a DC charger for a modern smartphone outputs) if it detects it is a USB port. The official standard sets USB 2.0 current levels at 500mA and 3.0 at 950mA. It is not uncommon for USB ports to support 1A or higher though, especially on laptops. The problem lies with the phones. Some ...


13

The answer is a definite maybe. I'll explain. USB Type-C is a special beast. It's a "smart" cable, with requirements beyond a standard USB cable. The specifications do not provide for a power-only cable, so the answer is really to the questions of how long can a compliant Type-C cable be, and can you have a longer non-compliant cable? Standard USB 3.0 ...


12

Shorter answer. Fairly simple question, do USB 2.0 devices charge quicker if they are plugged into a USB 3.0 port rather than a USB 2.0 one. I’m not asking about a specific device I have, I just mean in general. Yes, no and maybe is the answer. While you are asking this question as a general, non-device specific question, the reality is it’s ...


10

I hooked up a Lenovo 65-watt adapter to a good Wattmeter and it drew less than 1 watt after the first "surge" of plugging in (2 watts). I tried an Apple adapter and it did not even register. Ordinary good quality adapters do not draw appreciable current and can be left plugged in without any concern. I trust this helps.


9

I've been trying to find an answer to the question at the top of this page, and so far have not found anyone who has actually measured things. Lots of people say "should" and "might" and "generally" but there is no actual answer. Having the equipment to do so, I did so. I measured the voltage and current coming from my USB power source (more on that later)...


9

Some laptops won't charge the battery back to 100% until it falls below a certain threshold, e.g 95%. This is to prevent unnecessary charging that would reduce the battery's lifespan, since batteries constantly self discharge. Try using the laptop on battery for 30 mins or so to discharge it a bit then plug it in to see if it charges up to 100%. Also, you ...


8

I didn't find a pure Software solution, so I've set up a quick hack based on the Belkin WeMo Switch and a Node.js app. The WeMo is a power outlet that can be switched on and off via Wifi. So you can plug your laptop charger on the WeMo, and a script or an app running on your laptop monitor the battery and switch the outlet on and off accordingly. Edit: more ...


8

I know that this question is 2 years old, but this issue still pertains to this day, and might still be of relevance to some people. I'll be sharing a solution that I found. I'll guess that OP has a laptop with an AMD GPU/iGPU. Basically the graphics driver is causing the screen to dim. To fix this, right click your desktop, then (probably at the top of the ...


8

No, what you "want" is not that simple. Most hubs are not designed to conduct the current backwards from downstream ports to upstream. Even if some cheap hubs do have the direct connection, the tablet will not recognize the cable as a charger cable, will continue to be in HOST mode (which means supplying VBUS, not consuming), and obviously will not charge ...


7

All of the answers here have been useful in parts to answer my question, so I'm creating a community wiki answer. Please scroll and upvote them! It will depend on the quality of your adapter. So unless you're sure, better turn it off. Mario's answer gives us a way of testing how your adapter behaves, using which John's answer reported how two laptop ...


6

To choose the right charger for the right device increases the rate of charging, increases the lifespan of the device and decreases the risk of burn. There is always a risk of burn, but it can be minimized by many methods. Ohm's law V = R I where V voltage, R resistance, and I current. Choose a cable which has more/same charge capacity (I) than the phone. ...


6

Your computer's charger and the computer itself will prevent overcharging of the battery. Depending on how your computer's manufacturer set it up, you may actually see it stop charging after 95% or 98%, but most will show it going to 100% and still say charging, even though it is actually running off of the charger but not adding power to the battery. ...


6

As was highlighted in the comments, this is not OS specific, but a BIOS problem. The approach I took should work for most HP models from mid 2011 to at least the time of writing, as well as any computer running a similar BIOS, and probably others too Firstly, use the Fast Charging port if your computer has one (see picture, lightning symbol, USB 2.0) ...


6

The S10 charger is probably limited to 9V and 1.7amps of current, probably putting out 15 watts of power. It might even be able to give 25 watts. (A little above 2.5 amps). It is intended to charge a phone with a small 3.7V battery. Your laptop probably expects either 12V, 15V, or 20V in order to charge. It has a much larger set of batteries to charge and ...


5

The plugs are the first thing to look at. If the plug doesn't fit, you obviously can't use the brick with the device. Following that is the voltage. If this doesn't match the device, don't try it since you could damage the device. After that is the current. It's acceptable to supply more current than required, but don't try one with less or the voltage ...


5

The proper solution is via diskpart's automount disable command C:\Windows\system32>diskpart Microsoft DiskPart version 6.3.9600 Copyright (C) 1999-2013 Microsoft Corporation. On computer: WIN81 DISKPART> automount Automatic mounting of new volumes enabled. DISKPART> automount disable Automatic mounting of new volumes disabled. DISKPART> ...


5

Your battery could be faulty, and at that age, its certainly under warranty. However, before you find your local service center for the laptop, you should probably try caliberating the battery. If you have the usual thinkpad power control application, its there - otherwise, it seems you can do it from something called one key optimiser. If caliberation ...


5

Unless your laptop doesn't have a battery, you're fine. Leaving it plugged in all day, everyday can minutely reduce your battery's efficiency. But since your battery degrades overtime anyway, that's not really an issue. Lithium batteries don't last forever, nor retain their peak efficiency indefinitely.


5

All information can be found on www.usb.org. The rate how fast a device charges itself depends on three factors: What kind of charger signatures the device can understand, and What kind of signature a USB port provides. What is the charging limit for a particular battery embedded into design. Not long ago the USB ports were meant to adhere to so-called ...


5

You don't need to reduce anything. The headset is designed with a particular internal battery that has particular charging specifications, and its circuitry will not take more than whatever it is designed for (450mA in your case), no matter how capable the 5V source is, 1A or 10A or 30A. FYI, USB cables do not "demand" anything. At most, if they have Type-C ...


5

Batteries have a finite life, there are a lot of different aspect involved in a battery life; however the one we concern about here is "Cycle life". The cycle life is the number of complete charge/discharge cycles that the battery is able to support before that its capacity falls under 80% of it's original capacity. [1] In an other words: In general, ...


5

You should be able to select the direction from the USB menu on the phone, accessible from a persistent notification when the cable is plugged in. Just expand your notification menu and tap the USB one to bring up the menu. Alternatively, the same menu can be found in the phone's Settings app. Screenshot from http://www.deteched.com/2017/05/01/samsung-...


4

Expanding on tapped-out's answer. These chargers work the same way the internal power of a desktop computer would work. When you buy, for example, a gaming computer you will notice PSU (power supply unit) options exist which run way above and beyond the requirements of anything you could ever likely get inside the case. Obviously if the PSU controlled how ...


Only top voted, non community-wiki answers of a minimum length are eligible