Watts law, Power in Watts is equal to the inductive resistance in amps times the voltage. P=I*V.Hi all, new to RPi community and first post here
I am building a RPi 3B based system to be deployed in the middle of nowhere. The Raspberry Pi 3 Model B requires a 5.1V 2.5A power source, and for this system to run for 3 days would need energy 5.1*2.5*24*3 = 918kW.
My first thought was to use a power bank, but many discussions on stackoverflow and this forum suggest it may not be a reliable idea, especially on the long run.
I wanted to know if someone here has implemented a system as such and what they have used in their practical experience.
You know your amps, 2.5, and you know your volts, 5.1 which gives us 12.75w, so watt hours is 12.75 if I am figuring this correctly. We have commonly established fact that 3 days is equal to 72 hours more or less. We can quibble about the time it takes to make the leap year but I honestly don't care... Anyway, so yes your math adds up, 918w/hrs consumed.
Now are you tapping directly off of say a 12 or 24 volt battery, or will you be using an inverter as inverters eat up a bit of power, let's be cautious and say for 3 days your combined power total need is 1100 w/hrs.
Are you planning on having some means of charging the battery or are you going to let it go flat and be done with it?
Okay so a little background. I am setting up a camper for off grid use as well, running Pi5, so I have been looking into this, but with a lot more load than you are talking about... In your application though....
I went with Chins LiFePo4 smart battery, I used the 400 amp hour model which would be overkill for just a Pi3, a 200 amp hour model is rated at 2560w/hr. WAY more than you need, but as batteries go down in charge the voltage drops too....
For that battery, you are going to want some way to charge it, shove about 20 amps at 18V through a charge controller. I.E. you will want a solar panel kit. In my application, I did not want permanently mounted so I can move the panels without moving everything else...
300w is just under 20 amps I used the Dokio 300w kit, but in mine I paired 2 of them up with a parallel cable into a larger charge controller....
https://amzn.to/44so30q
The Dokio panels work great, but have no stands, you are going to need panel stands. https://amzn.to/44ol8pm
Now, this is as simple as it gets, Follow the getting started guide on the panel kit, connect positive to battery positive, and negative to battery negative and THEN connect the panel to the charge controller, you do not want power being produced while you make the connections!
If you have any questions, just ask. I will get you are far as I went with my setup my asking a lot of questions and getting a lot of good answers...
https://amzn.to/4bg8BHv
Statistics: Posted by dbhosttexas — Fri May 03, 2024 3:42 am