26
Go to a hobby store (or DX.com) and buy a BEC (battery eliminator circuit) intended for model aircraft. $5 gets you a very efficient switch mode voltage regulator, good for around 3A. I use these with all my Pis.
Here is an example: http://dx.com/p/hobbywing-5v-6v-3a-switch-mode-ultimate-bec-ubec-15149
23
Short answer
Yes, most (but not all!) USB power banks are capable of powering a Raspberry Pi, since they usually have an output voltage of 5 V. And yes, by using a (quite large) 50 Ah power bank, you can definitely expect your Pi to run for at least 24 h. See the long answer below for reasoning and further relevant aspects.
Long answer
According to actual ...
16
The Raspberry Pi Wiki entry on power suggests this is possible (emphasis mine):
Back-Powering; (powering the Raspberry Pi from a USB hub through the uplink/data port, single cable) Back powering is possible on the Raspberry Pi. Revision 1.0 boards have to be modified to back power, this is due to the 140ma "polyfuses" that are installed in the USB port ...
11
It's possible to power your RPi through your USB hub on two conditions:
the hub does not backfeed: this is easy to test; remove the SD card, connect the RPi's USB port (not micro USB port) to the hub. If the RPi's led doesn't come on the hub doesn't backfeed. If the hub does backfeed you can't use this hub with the RPi.
the power supply of the hub is ...
10
The question seems to be inadequately answered. The best alternative would be a switching mode power supply with simple circuitry such as this:
Although 7805s work well, it's not scalable in the long run. Say you want to add a Camera Module or some other module. It'll be able to drive the circuit but cannot withstand high loads for a long time.
The data ...
10
As long as the power bank outputs 5V it will power the Pi.
It claims 50000mAh so it claims 2.5 amps per hour for 24 hours. Assume it will deliver half that so 1.25 amps for 24 hours.
If that is enough or not will depend on what you have connected and what the Pi is doing.
9
Here is my setup: 30 watt solar panel with a 12 volt charger hooked up to a 33 amp hour, 12 volt battery. Off of the battery I have a 12 volt to 5 volt battery eliminator that drops the voltage safely to 5 volts that I spliced into a micro USB cord.
It's been running successfully for two days now. I would like to experiment with a smaller battery and panel ...
9
Yes, should do
Just double checking the datasheet of the MT3608:
if using AA rechargables instead of batteries, mind the lower voltage (cell voltage 1.2 V), but for two cells in series still above the lower lockout voltage (2 V) of the MT3608
at very low input voltages the efficiency could be lower than 80 %, the datasheet (p. 5) lists 80 % at 3 V and a ...
8
The Pi should not be powered from it's own USB ports. It's not a safe way of supplying power. The correct way is to use either the micro USB port or the correct GPIO pins.
The hub you have is at fault here - it shouldn't be supplying power upstream along the data feed cable. You may have to take it apart and cut a wire.
Powering the Pi from two places is ...
8
No you cannot power the Raspberry Pi using its USB ports. The micro usb is the only way to power the RPi, apart from some other hacks I've seen involving solder (read the update).
Although it's not completely impossible, but you'd have to modify the RPi quite a bit to get that right. Please have a look to the Model B Rev 2.0 schematics.
UPDATE: As ...
8
I got this battery powered USB cell phone charger, and a couple of lithium 18650 batteries. It did a pretty good job and ran for 5.5 hours when idle and over 4 hours when running a Quake 3 demo loop. You can read about my testing methodology here. These 18650 lithim batteries work great because they are high enough voltage that just 2 batteries will easily ...
8
You have to be careful with those 7805's. If you remove power from the 6V side while a powered hub is connected for instance - the 7805 will be reversed biased. This is the archilles heal of the 78XX series. You can help it out somewhat by putting a reverse biased diode (anode to the 5V side) from the input to the output.
Additionally, the 7805 are old ...
8
The batteries won't force current through the system. Your bigger problem, though, will be running the Raspberry Pi 2 at all on 4.8 V. It's very close to under-voltage warning (which I saw quoted as 4.65V for the B+). You'll need some kind of DC-DC converter to get the voltage to consistently ≥5V.
8
Based on your picture, it looks like the power switch is flipped off. If you look at the board oriented with RPi PowerPack V1.2 at the top, you'll notice there's a switch at the very bottom of the board. Switch it to On.
I'm not sure if this matters, but in the images provided by your link, they all show the RPi being plugged into the top USB port. If they'...
7
As far as I know, you can't.
But by using some very simple electronics you can. The most simple and straight forward option is to use 2 GPIO pins as input (one for each power supply).
Connect both power supplies (besides to their normal connection to actually supply the power) through some resistors (for safety and voltage level adjustment!!) to these GPIO ...
7
Yes.
You can power it via the ground and 5V pins on the expansion header.
Once it's booted you can also back power it via the USB (although I
doubt that this is sensible).
Both those methods bypass any protection afforded by the 2 amp polyfuse.
6
I have not measured it myself, but this person claims the pi draws about 110 mA after shutdown, i.e., when the OS has halted and just the red PWR led glows.
Figures regarding the number of amp-hours in a car battery seem to vary quite widely; if we assume 50, then that's 50 / .11 ~= 454.5 hours such a battery should last with an inoperative pi attached. Of ...
6
Intro:
Many of my contributions to this forum have centered around innovative ways to power a Pi which is awkwardly out of reach of a mains socket, specifically using POE. But what do you do if there's no mains power source at all, ie: Pi used in off-grid conditions or mobile use where the Pi is not stationary?
As the Pi 4 now had a USB-C Power socket, I ...
5
Long story short -- there are a few waterproofs, you may even make your own using an acrylic sheet and a bit of glue. But there's no real solution for the solar battery power, the reliable solution that survive at least a few rainy days will include the truckload of batteries and dozens of square feet of the solar panels, driving the cost into the thousands.
...
5
Here's a writeup using six aa:
http://www.raspberrypi-spy.co.uk/2013/02/running-a-raspberry-pi-from-6-aa-batteries/
5
Never power any device from two sources. The source with the higher voltage will provide the reverse current to the other one and since power supplies have very low internal resistance (by design), eventually one of them will give you a smoke signal.
The correct mode of supplying power to RasPi is through microUSB connector, it has the short protection fuse ...
5
At a minimum you need: a solar panel, a charge controller, a deep cycle battery, a DC-DC buck converter (to reduce battery voltage to 5V), hardware to mount the panel, something to house all the components.
The trick is in sizing the solar components, and that depends on how much sunlight you get and how much reserve power you want. However, even under the ...
5
Here is what I did and it seems to work well:
You will need a 8xAA battery pack with a 9v battery like power connector.
A 2Amp USB car adapter
Optional - A plug to plug into the car adapter, otherwise just take the adapter apart.
Solder the center pin on the car adapter to the positive from the battery pack, or if you used the cable the appropriate wire. ...
5
One thing to be aware of is that those chargers are not regulated, so any spikes, surges, etc will be passed on to the Pi. I would think that regulator circuit like the one below would be a safer long term solution than a car charger. For prototyping, testing etc, your car charger would be fine.
5
According to Raspberry Pi forums, you can supply 5V with a ±5% uncertainty, meaning you could supply from 4.75 to 5.25 volts. The 7805 voltage regulator should be okay for your project, for it could supply a max of 1A and it stays within that uncertainty. This leaves you with an additional 250mA for connecting a keyboard or something else that doesn't ...
5
The header power is connected directly to the uUSB connector power and therefore you can power up to 2A through that power supply.
But there is still a current limited between 5V and VBUS on the USB so you're limited to pushing 1.2A out of the VBUS
So your total supply would be around 1.32A to the Pi Zero
5
The Pi draws about 300mA at 5V, plus whatever your GPS unit would draw. Ignoring the small losses associated with a (switching) step-down converter. Say a total of 2W. That would be equivalent to drawing 1/6A at 12V. If you have a 60Ah battery, it would last for 360h, or 15 days, give or take. So long as you move your car more than once a week, you should ...
5
The safer is to connect between PP1 (5V) and PP5 (GND).
You don't bypass the power fuse of the RPi.
5
You've not explained or shown how you have your batteries arranged, nor provided any specs on them. But it seems likely they are in series - thereby providing ~ 9V output.
Batteries in series can provide no more current that a single battery, and even a good quality AA cell isn't capable of much more than 1 amp. And so your battery pack will be unable to ...
4
Any external USB battery pack with built in overcharging protection will help your Pi survive power outage. It will simply work as a poor man UPS for your Pi.
http://www.google.com/search?ie=UTF-8&oe=utf-8&q=usb+battery+pack
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