A battery-powered USB Hub?

[SeagullOne]

Hello again everyone. I'm getting ready to finish my custom-built robot, NINA. One technical issue, though. My laptop only has two USB ports and I would need at least five to run the peripherals. I've been looking into getting a USB-4 port hub or two, but found out since I'm using a laptop that might quickly drain power! I then looked into seeing if anyone had any "battery-powered" USB hubs out there, but the only product I came across was Cyberpower 4-port battery powered USB hub. That only runs on four AAA batteries, and I'm rather skeptical that can provide adequate power of my robot's circuitry.

Could I just buy a self-powered USB hub and instead of using an AC adapter, plug a battery into it (at the right voltage of course ). To me, it only seems a matter that at the right voltage, the self-powered USB port will just soak up the proper current and nothing will be damaged. But with only a novice in actual electronics experience, I thought I'd check with some of you experts first.

Cheers!

[Admin]

since I'm using a laptop that might quickly drain power!

Thats only true if you are powering the external devices with USB. What devices are you using?

Without knowledge of what you are doing, here is a thought. USB has four wires, one of them being 5V power. Cut that wire, and attach it to a 5V regulator connected to a 6.5V+ battery. And make sure you keep grounds common!

[dunk]

Could I just buy a self-powered USB hub and instead of using an AC adapter, plug a battery into it (at the right voltage of course Grin)

yes. this works fine.

dunk.

[airman00]

USB ports only give 500mA maximum. 

a regular NiMH battery pack will give you 2300 mAH .  Thats over 2 hours of continuous runtime assuming the device is drawing the full 500mA ( highly unlikely)

[SeagullOne]

Thanks guys.

My laptop will be communicating with:

1) a Sabertooth 2x25 via packet sized serial (using a TTL to USB converter cable)

2) a Lynxmotion 32 Serial Servo controller (using a serial to USB cable)

3) a PIC microcontroller which will handle my robot's sensors (using a a TTL to serial and then a serial to USB...or just another TTL to USB)

4) Two cyber Snipa spotter webcams without the zoom lens (running a basic stereo vision setup in roborealm)

Thanks again, guys! I'll look into self-powered hubs and battery packs and see what'll work. 

Loren

[Admin]

for 1-3, the biggest power drain will be the LEDs (basically nothing)

the webcams however will probably draw ~200mA each (estimated based on my experience with other cams)

[SeagullOne]

Okay, thanks Admin.

So, on estimate, the most power drain I can expect is about 400ma (give or take a few milliamps).

I'll see how they perform on just my laptop via a bus-powered or self-powered USB hub (one with either option. That way, if I need to use an external power supply, I don't have to buy a whole 'nother USB hub.)

Thanks for all the input, guys!

Loren