Raspberry Pi Forums

I have an Edimax EW-7811UN 150Mbps Wireless Nano USB Adapter and have used it with my pi for a long time. It works very well and I am very happy with it. That is when I am using the raspberry pi with it and the raspberry pi is plugged into a blackberry micro usb charger (5V, 700mA) that it plugged into the mains. For my next pi project, the pi must move around a garden, therefore cannot be plugged into the mains. I decided to buy a power pack on amazon. I found JZK 20000mah Power bank External Battery Pack (http://www.amazon.co.uk/gp/product/B00C ... UTF8&psc=1). Apparently Port 1 is perfect for the raspberry pi because it outputs 5V at 1000mA. I have tried multiple micro usb to usb cables in this port connected to my pi. The pi works fine with all of them. But whenever I have my edimax wifi usb dongle plugged in, the pi refuses to work, it starts up and during that process, it comes up with an error. I took a picture of the error and will attached it. Does anyone have a solution?

That kind of suggests that the powerpack can't supply enough power for the Pi and your wifi dongle. I'm not sure what other conclusion could be drawn.

joan wrote:That kind of suggests that the powerpack can't supply enough power for the Pi and your wifi dongle. I'm not sure what other conclusion could be drawn.

But I have increased the power ?!?!?!?

Would it be too risky to try the other port on the power pack (because it has more power)? Should I try fully charging or discharging the power pack? Does anyone have any other ideas?

ZacharyI123 wrote:

joan wrote:That kind of suggests that the powerpack can't supply enough power for the Pi and your wifi dongle. I'm not sure what other conclusion could be drawn.

But I have increased the power ?!?!?!?

Would it be too risky to try the other port on the power pack (because it has more power)? Should I try fully charging or discharging the power pack? Does anyone have any other ideas?

Is there anything I can do? Is anyone else experiencing it? How did you solve it? Is the battery pack dodgy?

Thicker wire, lower impedance batteries. And mAh is not mA.

From what I read here: http://www.raspberrypi.org/phpBB3/viewt ... 2&p=354962
I have decided to reinstall NOOBSon the SD and boot straight from the battery pack (after charging it to full).
I will post what happens...

jackokring wrote:Thicker wire, lower impedance batteries. And mAh is not mA.

I bought everything off amazon. It does not take batteries, you charge it. Sorry about the mAh mA mistake. What needs thicker wire?

I installed a clean copy of raspbian wheezy onto the SD card, plugged the pi into an HDMI cable that is connect to a TV that has previously worked with the pi, connected to the edimax and keyboard via usb. I made it to the configuration screen and nothing happens when I press the keyboard and the edimax shows no lights. What is wrong with the power block?

ZacharyI123 wrote:I installed a clean copy of raspbian wheezy onto the SD card, plugged the pi into an HDMI cable that is connect to a TV that has previously worked with the pi, connected to the edimax and keyboard via usb. I made it to the configuration screen and nothing happens when I press the keyboard and the edimax shows no lights. What is wrong with the power block?

Should I return it?

Did you charge it for 20 hours?

joan wrote:Did you charge it for 20 hours?

Yes. I cannot use an ammeter or volt meter to check if they are what they are supposed to be because it outputs via USB.

ZacharyI123 wrote:

joan wrote:Did you charge it for 20 hours?

Yes. I cannot use an ammeter or volt meter to check if they are what they are supposed to be because it outputs via USB.

The chances are that the output voltage is a bit low. You can measure the supply voltage at test points on the Pi board.

Always measure a new power device before you connect it.
I have a battery pack sold as suitable for charging phones via USB, but it outputs 4.2 V. It will charge my phone but it won't run my Pi.

PiGraham wrote:

ZacharyI123 wrote:

joan wrote:Did you charge it for 20 hours?

Yes. I cannot use an ammeter or volt meter to check if they are what they are supposed to be because it outputs via USB.

The chances are that the output voltage is a bit low. You can measure the supply voltage at test points on the Pi board.

Always measure a new power device before you connect it.
I have a battery pack sold as suitable for charging phones via USB, but it outputs 4.2 V. It will charge my phone but it won't run my Pi.

Where are the test points? Do I just hook my voltmeter up with them?

ZacharyI123 wrote:Where are the test points? Do I just hook my voltmeter up with them?

Have a look here.