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Rpi 3B+: how cold can it still opperate?

Posted: Sun Mar 29, 2020 10:46 am
by travisfarmer
i have a 15KW Generac generator, and i will be attaching a Rpi 3B+ to it, running this project on it: https://github.com/jgyates/genmon
but as i live in Maine, USA, temps have been known to get down to -40*, and colder. will the Rpi still function?

if not, my next thought would be to use an XBEE S1, to bring the Rpi into the house.

Thanks in advance for any help. :D

~Travis

Re: Rpi 3B+: how cold can it still opperate?

Posted: Sun Mar 29, 2020 10:57 am
by DougieLawson
I think someone has had an original RPi1B down to temps lower than -40°F (which is, curiously, -40°C). I think there's a blog item or Magpi article about it.

https://copperhilltech.com/blog/raspber ... ure-range/

Re: Rpi 3B+: how cold can it still opperate?

Posted: Sun Mar 29, 2020 11:06 am
by travisfarmer
ok, thank you. i will proceed with the project, and see what happens.
if worst comes to worst, i could try the XBEE option.

~Travis

Re: Rpi 3B+: how cold can it still opperate?

Posted: Sun Mar 29, 2020 1:20 pm
by JohnsUPS
travisfarmer wrote:
Sun Mar 29, 2020 11:06 am
ok, thank you. i will proceed with the project, and see what happens.
if worst comes to worst, i could try the XBEE option.

~Travis
Keep in mind that the Xbee would have to function down to that temperature also.
If the generator is near the house, then just run the appropriate wiring into the house for the Pi. You wouldn't have to worry about the wireless link dropping out (even if the Xbee temp specs were suitable) either.

Re: Rpi 3B+: how cold can it still opperate?

Posted: Sun Mar 29, 2020 1:38 pm
by travisfarmer
could be possible... i looked up the RS-232 specs, and if i use CAT-5 cable, i should be able to reach the house. the advantage being that i don't have to know the Baud rate of the generator Aux port, as the software auto-detects, where the XBEE does not.
the Rpi will still have to be powered by the generator battery though, or i will have to plug it into a UPS. easy enough. with the current usage of the Rpi being low, i could use 2 pair for Tx and Rx (white pair tied to ground), and the other two pair for an additional ground, and the power supply (+12V from the battery, feeding a LM7805).

~Travis

Re: Rpi 3B+: how cold can it still opperate?

Posted: Sun Mar 29, 2020 1:43 pm
by DougieLawson
Could you not route some of the hot generator exhaust as a heat source to keep the microcontrollers and microcomputer warm.

Re: Rpi 3B+: how cold can it still opperate?

Posted: Sun Mar 29, 2020 2:19 pm
by travisfarmer
that would work fine, if the generator ran constantly. ;) it is a standby generator.
though it may be possible to put the Rpi in an insulated box, and install a small low wattage light bulb for heat.

~Travis

Re: Rpi 3B+: how cold can it still opperate?

Posted: Sun Mar 29, 2020 2:58 pm
by DougieLawson
Better than a lamp may be a peltier heater.

Re: Rpi 3B+: how cold can it still opperate?

Posted: Sun Mar 29, 2020 3:15 pm
by travisfarmer
just happened to think... this generator is supplied with a cold weather kit. it has a thermostatically controlled heat mat for the battery, and another wrapped around the oil filter to warm the oil. both are set to turn on at less than 40*F. the oil filter heater i like. as for the battery heater, the battery is charged by a maintainer/charger built into the generator controller, and everybody knows a charged battery is very unlikely to freeze. the cold weather kit is not required for winter starting, so i could possibly use the battery mat inside a insulated box to keep the Rpi warm. i just have to route 240Vac (low current, 20AWG feed wires) into the box. though in doing this, i may want to fashion a Faraday cage around the heater mat, just to cut interference...

~Travis

Re: Rpi 3B+: how cold can it still opperate?

Posted: Sun Mar 29, 2020 8:32 pm
by Imperf3kt
DougieLawson wrote:
Sun Mar 29, 2020 10:57 am
I think someone has had an original RPi1B down to temps lower than -40°F (which is, curiously, -40°C).
Unless things are different 15,000km away, -40°F is 4.4^°C in Australia.


I recall slmebody using a Pi in Antarctica just fine. Also there was some project at CERN where the Pi was used in up to -200°C environments.

The specs for the Pi say the LAN chip is only rated for 0°C to 70°C, but the rest of the Pi is rated for - 40°C to 80°C

Re: Rpi 3B+: how cold can it still opperate?

Posted: Sun Mar 29, 2020 8:48 pm
by davidcoton
Imperf3kt wrote:
Sun Mar 29, 2020 8:32 pm
Unless things are different 15,000km away, - 40°F is 4.4^°C in Australia.
Unless things are different in Australia to the rest of the world, it isn't.
Observe the minus sign.

Re: Rpi 3B+: how cold can it still opperate?

Posted: Sun Mar 29, 2020 9:24 pm
by Imperf3kt
-40F is not -40C
I did observe the minus sign, hence why I wrote that -40F is +4°C and within the Pi's rated operational range.

Re: Rpi 3B+: how cold can it still opperate?

Posted: Sun Mar 29, 2020 9:27 pm
by travisfarmer
google says differently.
https://www.google.com/search?q=-40F+to+c

-40 is the crossover point with F and C.

~Travis

Re: Rpi 3B+: how cold can it still opperate?

Posted: Sun Mar 29, 2020 9:34 pm
by Imperf3kt
I see what's happened here, while googling the oddity, I mistyped and left out the minus on the F scale somehow.

That's the first I've heard of the crossover, sorry about the mistake.

Re: Rpi 3B+: how cold can it still opperate?

Posted: Sun Mar 29, 2020 9:35 pm
by travisfarmer
not a problem. i admire one to admit when they are wrong. :)

~Travis

Re: Rpi 3B+: how cold can it still opperate?

Posted: Sun Mar 29, 2020 9:43 pm
by W. H. Heydt
Imperf3kt wrote:
Sun Mar 29, 2020 8:32 pm
DougieLawson wrote:
Sun Mar 29, 2020 10:57 am
I think someone has had an original RPi1B down to temps lower than -40°F (which is, curiously, -40°C).
Unless things are different 15,000km away, -40°F is 4.4^°C in Australia.


I recall slmebody using a Pi in Antarctica just fine. Also there was some project at CERN where the Pi was used in up to -200°C environments.

The specs for the Pi say the LAN chip is only rated for 0°C to 70°C, but the rest of the Pi is rated for - 40°C to 80°C
In the test at Cern, the Pi failed around -100'C. They *wanted* to see if it would run at -200'C (basically, liquid Nitorgen temperature). However, the capacitors on the board went so far out of spec at -100'C that the Pi quit working at that point.

For those that didn't follow the link to the blog post about using a Pi to count penguins in Antarctica. the Pi worked just fine down to -42'C...when the batteries froze.

For the OP...doubt you're going to have a thermal problem with the Pi. You'll be out of spec, so not relying on a given board until you've tested it would be a really good idea. If you can position the Pi so it's on the house-facing side of the generator, it'll probably be a bit warmer than on the other side due to IR leakage from your house.

Re: Rpi 3B+: how cold can it still opperate?

Posted: Sun Mar 29, 2020 9:57 pm
by travisfarmer
W. H. Heydt wrote:
Sun Mar 29, 2020 9:43 pm
For the OP...doubt you're going to have a thermal problem with the Pi. You'll be out of spec, so not relying on a given board until you've tested it would be a really good idea. If you can position the Pi so it's on the house-facing side of the generator, it'll probably be a bit warmer than on the other side due to IR leakage from your house.
ok, thank you. i may still heat the Rpi enclosure, just to maintain reliability, in case i get a super cold spell. in the least, it won't cost me anything extra to use the battery heater mat, or i can even buy an extra. i don't think they cost a huge amount, on eBay (used). the Rpi needs an enclosure anyway, so i may as well insulate it.

currently i am waiting for an adapter plug to arrive so i can interface with the generator controller. well, that and propane for the generator...

~Travis

Re: Rpi 3B+: how cold can it still opperate?

Posted: Thu Apr 02, 2020 1:07 am
by pfletch101
travisfarmer wrote:
Sun Mar 29, 2020 9:57 pm
W. H. Heydt wrote:
Sun Mar 29, 2020 9:43 pm
For the OP...doubt you're going to have a thermal problem with the Pi. You'll be out of spec, so not relying on a given board until you've tested it would be a really good idea. If you can position the Pi so it's on the house-facing side of the generator, it'll probably be a bit warmer than on the other side due to IR leakage from your house.
ok, thank you. i may still heat the Rpi enclosure, just to maintain reliability, in case i get a super cold spell. in the least, it won't cost me anything extra to use the battery heater mat, or i can even buy an extra. i don't think they cost a huge amount, on eBay (used). the Rpi needs an enclosure anyway, so i may as well insulate it.

currently i am waiting for an adapter plug to arrive so i can interface with the generator controller. well, that and propane for the generator...

~Travis
Just a thought - if you put the Pi in a really well-insulated enclosure, it should stay considerably warmer than ambient as a result of its own heat dissipation. You might have to open the enclosure during the summer, though.

Re: Rpi 3B+: how cold can it still opperate?

Posted: Thu Apr 02, 2020 7:23 am
by lpsw
I live in central Maine and have had 6 Pis deployed outside 365 (sometimes 366) days a year, for approx 3 winter seasons. All but one are Pi0Ws, in small Styrofoam boxes with a rectangular hole cut in the bottom, covered by a screen to keep out little heat seeking critters. The other Pi is a 4B4G that is on my deck, not as exposed to the elements as the Pi0s. They all connect to an outdoor long range WiFi access point. None have had any issues whatsoever in the winter. No 3B+ but I would expect a 3B+ to be OK.
You must live in the County? -40F country for sure . I'm from up there. Love it.

Re: Rpi 3B+: how cold can it still opperate?

Posted: Thu Apr 02, 2020 7:37 am
by travisfarmer
lpsw wrote: I live in central Maine and have had 6 Pis deployed outside 365 (sometimes 366) days a year, for approx 3 winter seasons. All but one are Pi0Ws, in small Styrofoam boxes with a rectangular hole cut in the bottom, covered by a screen to keep out little heat seeking critters. The other Pi is a 4B4G that is on my deck, not as exposed to the elements as the Pi0s. They all connect to an outdoor long range WiFi access point. None have had any issues whatsoever in the winter. No 3B+ but I would expect a 3B+ to be OK.
You must live in the County? -40F country for sure . I'm from up there. Love it.
Hmm, i do tend to overthink my projects quite often...
as for living in "The County", nope. Franklin county. no -40F this year, but plenty in previous years. i love this area, but the mountains do make for some fairly extreme weather at times.

~Travis

Re: Rpi 3B+: how cold can it still opperate?

Posted: Thu Apr 02, 2020 7:45 am
by lpsw
This summer I'm planning to install a solar powered Pi as a game camera at my camp in Eustis. Next winter should be interesting.
Love it there too.

Re: Rpi 3B+: how cold can it still opperate?

Posted: Thu Apr 02, 2020 7:56 am
by travisfarmer
lpsw wrote: This summer I'm planning to install a solar powered Pi as a game camera at my camp in Eustis. Next winter should be interesting.
Love it there too.
let me know how it works out. i get deer feeding in my yard from time to time. a Pi game camera would be neat, if my WiFi reaches that far, that is. ( i can check with my tablet)

~Travis