USB charging from PC USB ports?

Getting a new Olight S1R today(actually waiting for it to be delivered as I type this...),

and I'm wondering,how well does this light charge when plugged into a computer's USB port?

AMD64Blondie said:

Getting a new Olight S1R today(actually waiting for it to be delivered as I type this...),

and I'm wondering,how well does this light charge when plugged into a computer's USB port?

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I have several lights that I regularly charge from 2 computers. I don't have an S1R, but you should have no problems. I have, on occasion had the computer message me that too many amps are drawn from the USB port with some devices. That is rare, but it can happen.

AMD64Blondie said:

Getting a new Olight S1R today(actually waiting for it to be delivered as I type this...),

and I'm wondering,how well does this light charge when plugged into a computer's USB port?

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A computer port is usual very stable in voltage, but may complain if the device draws more than 0.5A

I would use a usb meter with a usb charger and check the current consumption, if it is 0.5A or below, it is safe to use with a computer. If it is more it may work or it may damage the computer (Not very likely, but I would not use it on a new expensive computer).

Try using an old wall phone charger android or apple both work great for my MH23. Very compact most people have spares.

The USB 2.0 spec limited current available to 0.5A. The USB 3.0 spec upped that to 1.5A. The thing is, unless you have a power only charging cable, the PC is going to see the data lines on the device and drop you back to 0.5A. Now, for many lights that would still be an adequate charging rate, but larger capacity cells will take a l o n g time.

I would advice against charging anything at PC's USB ports. I have damaged two USB ports in the past due to charging and obviously stopped doing that. After they got damaged, they can't recognize anything, all devices plugged at these USB ports reported as malfunctioning (they of course work just fine when plugged in other ports which haven't been used for charging). Your best solution is to get a phone charger or a wall plug that also provide USB outputs. For the few bucks these solutions cost, I wouldn't risk my PC.
I suspect the reason is, although these ports can provide the specified amount of current, they aren't designed to sustain that for a long time the same way a dedicated charger can. YMMV of course.

I've burned out motherboards charging drone batteries in a USB port. : (

apagogeas said:

I have damaged two USB ports in the past due to charging and obviously stopped doing that.

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Bigburly912 said:

I've burned out motherboards charging drone batteries in a USB port. : (

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Huh? Why would that damage your computer? USB ports are used for all kinds of charging and power requirements necessary for computing. Things like powering portable hard drives, charging bluetooth speakers, transferring data from smart phones and tablets (and obviously charging them while you're doing it).

What is your device doing that is damaging the USB port or motherboard? Is it demanding more current from the USB port than it's designed for? I thought the computer would limit that even if a dumb device didn't.

It sounds like the computer is designed with crappy components, if it's being fried from charging something via USB.

PC's are not designed for high charger current, in some USB ports it is possible to negotiate more current, but chargers usual ignores this and just draw a high current . This may be fatal for a port not designed for it.

HKJ said:

PC's are not designed for high charger current, in some USB ports it is possible to negotiate more current, but chargers usual ignores this and just draw a high current . This may be fatal for a port not designed for it.

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Are you saying that a charger can draw more than 0.5A from a USB port? (Or 1.5A from more recent implementations.)

Or are you saying that the ports are only designed to handle 0.5A for short periods of time, and not hours like a charger would drain? I'm not sure I believe that is the case, because portable external hard drives use close to 0.5A when active, and backups can take hours.

WalkIntoTheLight said:

Are you saying that a charger can draw more than 0.5A from a USB port? (Or 1.5A from more recent implementations.)

Or are you saying that the ports are only designed to handle 0.5A for short periods of time, and not hours like a charger would drain? I'm not sure I believe that is the case, because portable external hard drives use close to 0.5A when active, and backups can take hours.

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I doubt (although I haven't measured yet) a typical HDD will only peak at 0.5A (i.e. spin up the motor) for a short time and it actually draws quite less than that at its typical use. Same for other typical devices that are meant to be plugged in PC's USB ports. I have already burnt 2 USB ports on my motherboard - and by no means it was a cheap one) by charging a vape device, the first time I thought it just happened, the second time I did blame the charge, vape devices will charge at the maximum the port can provide all the time till they are almost fully charged. I had the same impression, I can charge everything there but it seems motherboards may lack the ability to protect the USB component from excessive use/heat or whatever causes the USB port to fail as they are not really meant for this task.
Both ports where burnt in about 4 months time period. Its been 3 years now, both these ports never got operational after the vaping device charges - were just fine before the first ever charge. So, the best bet is to skip USB charging from motherboards and use dedicated chargers. They are really cheap why risk your motherboard anyway?

I agree with not using PC usb ports for charging devices these days as too often things want to draw more than 500ma and some USB ports don't handle it well. You are better to invest in a separate AC usb charger instead they are cheap these days and plentiful.
There are some computers that usb built in wifi powered and connected directly to a usb controller and if you damage that controller you can pretty much toast the wifi adapter.

WalkIntoTheLight said:

Are you saying that a charger can draw more than 0.5A from a USB port? (Or 1.5A from more recent implementations.)

Or are you saying that the ports are only designed to handle 0.5A for short periods of time, and not hours like a charger would drain? I'm not sure I believe that is the case, because portable external hard drives use close to 0.5A when active, and backups can take hours.

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It is very common for a charger to draw 2A from a USB port (You can see that in my curves) without getting permission.

HKJ said:

It is very common for a charger to draw 2A from a USB port (You can see that in my curves) without getting permission.

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Interesting, I thought if a USB port was 0.5A, that's all it would provide.

I presume that smart phones and stuff like that must do proper negotiation? That is, smart devices are okay to charge via USB, but cheap/bad chargers are not?

WalkIntoTheLight said:

Interesting, I thought if a USB port was 0.5A, that's all it would provide.

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The PC power supply can supply lots of amps and the ports are not always well protected.

WalkIntoTheLight said:

I presume that smart phones and stuff like that must do proper negotiation? That is, smart devices are okay to charge via USB, but cheap/bad chargers are not?

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Phones and tablets follows protocol, but most stuff that do not talk on usb, only takes power, do not.

HKJ said:

It is very common for a charger to draw 2A from a USB port (You can see that in my curves) without getting permission.

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That's interesting. I am working through some issues with the charge rate on my Asus tablet. I usually have it plugged into a wall wart (Anker) that is capable of providing 20W. Yet when I check what my tablet is drawing with my USB Meter, it is only drawing 0.5A. I get the same draw when I use a USB 3 port on my PC as well. Yet when I plug it into my powerbank, it draws a full one amp. Any light you can shed on this would be appreciated.

Timothybil said:

That's interesting. I am working through some issues with the charge rate on my Asus tablet. I usually have it plugged into a wall wart (Anker) that is capable of providing 20W. Yet when I check what my tablet is drawing with my USB Meter, it is only drawing 0.5A. I get the same draw when I use a USB 3 port on my PC as well. Yet when I plug it into my powerbank, it draws a full one amp. Any light you can shed on this would be appreciated.

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This has to do with coding of the usb connector, I wrote about it here: https://lygte-info.dk/info/USBinfo UK.html

Timothybil said:

That's interesting. I am working through some issues with the charge rate on my Asus tablet. I usually have it plugged into a wall wart (Anker) that is capable of providing 20W. Yet when I check what my tablet is drawing with my USB Meter, it is only drawing 0.5A. I get the same draw when I use a USB 3 port on my PC as well. Yet when I plug it into my powerbank, it draws a full one amp. Any light you can shed on this would be appreciated.

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My Amazon Fire HDX 8.9" 2014 4th Gen tablet does this on occasion too, I think it's due to me pluging the charger cable into the tablet too aggressively and might have done a bit of damage to the tablet's USB port. It usually takes a few plug and unplug attempts to get the tablet to take the full 1.7A charge from the 2.0A Samsung USB charger. You can try pluging in the charger cable a few times to see if the AMPs increases, if it does you're in the same position as me and will have to buy and replace the USB header on the charging ribbon.

edit:

So HKJ, the erratic charging have nothing to do with a dodgy USB head? if so I won't be opening my tablet to replace the head as it's a major PITA to do.

john1230 said:

So HKJ, the erratic charging have nothing to do with a dodgy USB head? if so I won't be opening my tablet to replace the head as it's a major PITA to do.

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Because charge communication is on the data lines, any fault in them (Connector or cable) will affect fast charging. I recently had to replace a USB cable due to that (Broken data line).

HKJ said:

Because charge communication is on the data lines, any fault in them (Connector or cable) will affect fast charging. I recently had to replace a USB cable due to that (Broken data line).

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I suspected something like that, so I am waiting on the delivery of a power only (only two wires) USB cable to test with. You give me hope that that will help my situation.