If you mean you might need a battery capable of acting as the only supply or as a backup to mains for a period of three weeks, then that will be a large battery.tmcglasgow wrote:Six Raspberry pi's on one wall. Prefer one power supply.
I need mains power running 24/7 for three weeks?
Any guidance or recommendations?
Yes you can. The reason is that it is actually NOT a charger, but a power supply.hIrVaRi wrote:can i use charger with 2 usb slots and 5V, 2.1A?
No.hIrVaRi wrote:Will it harm raspberry?
Tarcas wrote:Three ways to apply power:
Responding in particular to hIrVaRi, but for other people with similar questions, this might help:
If you think of electricity like flowing water, this might make more sense and help you remember...
Voltage is like pressure. If you have too little, your equipment won't work, but if you have too much it may be damaged, or even explode. Voltage of the supply must MATCH the input requirements. The Pi takes 5v (actually 4.8 to 5.2, IIRC, but get as close to 5v as you can.) Too much voltage to your equipment is like too much pressure to the toilet. A little more (~9v) and things may break. A lot more (24+v) and you're going to have water on the ceiling. Don't do that.
Current, AKA Amperage is like water flow. Your power supply will supply up to 2.1A of current, but the Pi will only draw about 0.7A. Since the pressure matches, this is safe. When selecting a power supply, the rating must MATCH OR EXCEED the sum of the amperage ratings of all equipment being supplied by it. Going too high is actually good, since you're placing less demand on the equipment than it is designed for, causing less wear and tear. It's like having a bigger supply line to your house... You might not need or use all that capacity, but it won't cause any problems, and you can easily handle certain problems with that supply line.
Basic stuff this, therefore moved to beginners forum!TheDoctor1212 wrote:Hello,
I am kinda confused as to what I need for a power supply, can someone help me out? Will a standard android phone charger plugged into an adapter work? Is it the right sized plug? I also have a NDS Light charger which is 5.2V and 450Ma will that charge it, or does it have the wrong plug? If yuo cannot answer my questions a link to a charger for the raspberry pi that can just plug one end in to a power socket and the other into the rpi would be great.
the PI doesn't need "charging", it needs to be fed a nice stable 5 Volt, regulated within a quarter of a volt, from a supply that can deliver at least one Ampere, (bare minimum is 0.7A, (700 mA) but only if you use frugal USB devices) through a micro_USB input.I also have a NDS Light charger which is 5.2V and 450Ma will that charge it
Explanation which you'll remember for the rest of life:G00sfraba wrote:Is it harmful to connect the Pi to 3A power supply?
That supply looks OK. Your assumption is correct. The RPi will only take what current (which is measured in Amperes) it needs. As long as the supply is capable of giving at least that. Extra current supplying capability (which is unused) is not not a problem.G00sfraba wrote:Hello from me too
I want to create one Car automation project which involves both Rasppi and Arduino.
My drama is that I am not quite familiar with how the amperage works. Let me explain in detail:
There will be several components, which will be powered separately
1) Rasppi board
2) Arduino board
3) External USB hub
4) Various things controlled by the arduino and the Pi GPIO.
Ok now I have read the specifications for the Rasppi and I am aware that I need 700~1500 mAh which is 0.7 ~ 1.5 Amps
As I am going to build custom power supply which will power all my components there will be several different components in this supply. The component I am planing to use for the Rasppi power supply is this: http://www.ebay.com/itm/gib-Car-Charger ... 1202073503
Now the question is: Is it harmful to connect the Pi to 3A power supply? If yes, what car power supply will I need? Model? AC? DC?
And if somebody can explains to me what is the difference between 1,5 A and 3 A it will be great. I assume it is not important how much the supply gives, but how much the consumer takes out of the supply? The supply is not giving all the 3 Amps 100% of the time, only the amount which the consumer requires?