rpinewsymphony
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How many Ampere hour of battery needed to power raspberry pi 3 for 24/7 using solar panel?

Thu Oct 31, 2019 9:14 am

We are currently using raspberry pi 3 with fan, 3 infrared sensors, 1 ultrasonic sensor and 1 rain sensor. Our solar panel is rated 50W and we would like to power our rpi 3 24/7, can you recommend us how many Ampere hour of lithium ion battery needed to operate it 24 hours? thank you.

LTolledo
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Re: How many Ampere hour of battery needed to power raspberry pi 3 for 24/7 using solar panel?

Thu Oct 31, 2019 10:43 am

Hint:
convert all power requirements of all devices connected to the power source into watts (as the saying goes.....google it!)
add those up
multiply by the number of hours you would use
add safety factor
recheck your calculation again....
then convert result to ampere-hour (this might serve as your baseline value)
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Gavinmc42
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Re: How many Ampere hour of battery needed to power raspberry pi 3 for 24/7 using solar panel?

Fri Nov 01, 2019 2:21 am

You will note that that was a 100W panel 240W/hr battery for a ZeroW.
What will be needed for a Pi3?

Something to check is the new hibernate feature of the Pi4.
There is a 3pin header position that could be connected to a low power micro to wake up the Pi4.
So what is the current consumption of a Pi4 in hibernate/sleep?

Depending on this figure and the cycle time the Pi4 might be a better solution than a 3 or even a Zero.
This might be a good use for the 1GB Pi4's.
Time to search up the sleep current of the Pi4.
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Gavinmc42
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Re: How many Ampere hour of battery needed to power raspberry pi 3 for 24/7 using solar panel?

Fri Nov 01, 2019 5:46 am

Some more info on low power modes, did not know 3B+ can be as low as 11ma.
https://www.raspberrypi.org/forums/view ... p#p1484986

Getting the sleep current down on Pi's reduces the battery and solar requirements.
A way to wake them up again is need, RTC clock with alarm output, small micro etc.

A 24/7 on Pi is another story, back to 100W solar etc.
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drgeoff
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Re: How many Ampere hour of battery needed to power raspberry pi 3 for 24/7 using solar panel?

Fri Nov 01, 2019 8:00 am

Location?

As an extreme example, if north of the Arctic Circle you will need a huge battery to run 24/7/365.

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Gavinmc42
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Re: How many Ampere hour of battery needed to power raspberry pi 3 for 24/7 using solar panel?

Mon Nov 04, 2019 3:08 am

I spotted an interesting YouTube review of a kickstarter.
A portable generator, that's basically just a big battery.
https://ecoflow.com/

Looks pretty cool for those taking their Pi's off grid.
Very handy for those who's power goes out in storm season too.
Capable of powering a fridge for a few hours etc

It looks like an all in one solution so is probably going to be more expensive.
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Imperf3kt
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Re: How many Ampere hour of battery needed to power raspberry pi 3 for 24/7 using solar panel?

Mon Nov 04, 2019 4:01 am

Gavinmc42 wrote:
Mon Nov 04, 2019 3:08 am
I spotted an interesting YouTube review of a kickstarter.
A portable generator, that's basically just a big battery.
https://ecoflow.com/
Looks like just a (large) compact UPS with built in usb chargers and an inverter that is charged by a solar panel.
I think it a stretch to call it a "generator"

We have a very similar thing where I work, essentially an encased SLA battery with mains charging and built in voltage regulation used for filtering the power that runs the computer systems and sensors due to the very noisy environment (due to dozens of very high power electric motors)
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W. H. Heydt
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Re: How many Ampere hour of battery needed to power raspberry pi 3 for 24/7 using solar panel?

Mon Nov 04, 2019 4:49 am

Imperf3kt wrote:
Mon Nov 04, 2019 4:01 am
Gavinmc42 wrote:
Mon Nov 04, 2019 3:08 am
I spotted an interesting YouTube review of a kickstarter.
A portable generator, that's basically just a big battery.
https://ecoflow.com/
Looks like just a (large) compact UPS with built in usb chargers and an inverter that is charged by a solar panel.
I think it a stretch to call it a "generator"
That was my impression as well. Now if something like that was based around a Hydrogen fuel cell, it would be very useful.
We have a very similar thing where I work, essentially an encased SLA battery with mains charging and built in voltage regulation used for filtering the power that runs the computer systems and sensors due to the very noisy environment (due to dozens of very high power electric motors)
The "traditional" solution for that situation is a line conditioner. I once solved a similar problem for a modem bank with line conditioners. My boss had never heard of them. UPSes were too much for his discretionary budget, but a pair of line conditioners weren't.

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Gavinmc42
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Re: How many Ampere hour of battery needed to power raspberry pi 3 for 24/7 using solar panel?

Mon Nov 04, 2019 6:03 am

SLA UPS's have been around for decades.
A portable 18650 based Lithium Ion powerbank this size is new to me.

"Generator" is a bit of a misnomer, but it takes low voltage and "generates" higher voltage AC.
Normally called inverters but adding a powerbank is interesting.
Next versions will have 21700 Tesla cells?

Solar panel input is handy too.
Is it enough for a Tiny house power unit?

I have an old PC UPS, just stick a LiFePO4 SLA replacement battery in it and add some handles?
Never thought of that before.
Storm proof a house, fridge and LED lights?
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