Convert USB power to DC power

[Super]

Hello,

I bought a USB power bank that packs 7800 mAh, but only includes 2 USB ports as output, here are the specs:

Specifications:

- Capacity; 7800 mAh
- Input: DC 5V / 1A
- Output 1: DC 5V / 1A
- Output 2: DC 5V / 2A
- Size: 3.74” x 2.28” x 0.75”
- Weight: 6.05 oz
- Overcurrent Protection Delay: 1S
- Short Circuit Protection Delay: 1S
- Working Temperature: 0-40°C
- Storage Temperature: -20-60°C

I want to either use one, or combine both of the USB ports to get a DC-out power plug, to charge something more substantial, like a laptop for a short amount of time.

Is this possible, and if so, how would it be done?

 

[4pyros]

You can only put half an amp thru a USB connector.
What is the modle of your power bank?

 

[Super]

RAVPower RP-PB09

 

[Externet]

Crack it open, tap the 5V supply before the current limiting for USB circuits, and wire it to a connector for the outside world.

If its guts is a near 5V battery, you will not be able to power a laptop with that. Get a car/motorcycle battery -or two- to feed a laptop.

 

[4pyros]

Thats ment for charging phones it will never charge a laptop. It would run out before it booted. Sorry

 

[Mike odom]

You can only put half an amp thru a USB connector.
What is the modle of your power bank?

USB connectors are rated for 1 amp (1.8 for the power pins).

View attachment USB-A1HSXX.pdf

 

[4pyros]

USB connectors are rated for 1 amp (1.8 for the power pins).

View attachment 69373 View attachment 69374

Maybe the connector its self.
USB standered is 500ma max.
Still will not charge a laptop.

 

[Mike odom]

Maybe the connector its self.
USB standered is 500ma max.
Still will not charge a laptop.

the attachment on the right IS the USB standard, which states 1 amp on signal pins, and 1.8A on power pins.

 

[4pyros]

the attachment on the right IS the USB standard, which states 1 amp on signal pins, and 1.8A on power pins.

View attachment 69384

Mike that is the spec of the connector made by that manufacter.
The USB standerds are a lot more complicated than that.
IE you can draw more power from a USB3 port than a USB2 port as long as comunicashoins has stopped.

The 500ma limit does have some exceptions, it's just a rule of thumb.

If you want to read up on it Wikipedia has a good condensed version of the standards.

Ether case that little box will never charge a laptop, it just does not have enough capacity.

 

[Mike odom]

Mike that is the spec of the connector made by that manufacter.
The USB standerds are a lot more complicated than that.
IE you can draw more power from a USB3 port than a USB2 port as long as comunicashoins has stopped.

The 500ma limit does have some exceptions, it's just a rule of thumb.

If you want to read up on it Wikipedia has a good condensed version of the standards.

Ether case that little box will never charge a laptop, it just does not have enough capacity.

no, the attachment on the left is the connector spec... the attachment on the right, and in my last post, IS THE USB STANDARD. Now, it does give a 1.8A when power applied with 500mA on the signal pins, and thermal rise not to exceed 30°C.
And I am not arguing that it will ever come close to charging a laptop, just that this is the USB standard... every phone charger I or my kids own rate the output at 5V and 1A.

I don't read wikipedia... I go straight for the KNOWN standard (I left the file name in the clip so you can see that it is the USB standard, not someone's interpretation of the standard).

Here is the entire standard if you want to peruse it... my clip came from page 33

View attachment Micro-USB_1_01.pdf

 

[4pyros]

Here is the entire standard if you want to peruse it... my clip came from page 33

Thats just part of it.

"MicroUSB Specification to the USB 2.0 Specification, Revision 1.01" The power box has full size ports.

and page 33 is the "Compliance Requirements" How hot thay can get under a certan load. Not the max current spec. or even the recomended max current.

None of witch have anything to do with what we are taking about.

 

[Mike odom]

Thats just part of it.

"MicroUSB Specification to the USB 2.0 Specification, Revision 1.01" The power box has full size ports.

and page 33 is the "Compliance Requirements" How hot thay can get under a certan load. Not the max current spec. or even the recomended max current.

None of witch have anything to do with what we are taking about.

max current ratings you mean, and it has everything to do with what we are talking about... you said max current rating was 500mA, but why would they rate the temp rise at 1.8A if the MAX is 500mA. The section is titled: Electrical Compliance Requirements, and the subsection is titled: Contact Current Rating... current rating... max contact current rating... and every max current rating is given with a thermal rise, pcb board trace width has 3 maximums, one for a 10°C rise, one for a 20°C rise, and one for a 30°C rise (for a given copper thickness). The NEC specifies wire sizes for a given current rating based on thermal rise. You can run more amps through the wire than is specified, right up to the copper melting point, but you're gonna inflame the insulation and surrounding building materials before you reach that point.

and I assume you mean which, and not witch, as I would be considered a warlock, not a witch...