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Solar panels + cold = A potential problem

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Re: Solar panels + cold = A potential problem

#51

Post by beefnugs »

xg15 wrote: post #46
teiferer wrote: post #25

Maybe they should just improve their product to make it more resiliant, rather than blaming customers for thinking that 148 V is below 150 V? Not everybody buying these has a Ph.D. in physics and if it says 148 V on the label and 150 V on the other label then it's your product that has a problem, not the customer. And no matter what happens, customer support should help the customer, not blame them.

This feels a bit like the logic behind "do not put hamster in microwave" warning labels. I think if you work with electrical or electronic systems in practice, you learn pretty quickly to respect tolerances and that data sheets are a map, not the territory. Also, electrical installations are usually seen as a field that should be done by trained personnel, not arbitrary laymen home owners. So I think the appropriate…

Actually if "you work with electrical or electronic systems in practice" you get pissed off at everything for how dumb it all is: 12V DC batteries are more like 14 nominal? AC wall plugs dip voltage when printers turn on, random equipment you arent even sure in the building can trigger UPSes based on unknown settings in the device? International standards and communication protocols mean nothing as "a standard" because each company has their own entire list of bugs/implementation mistakes. All the international enforcement certifications care way too much about inconsequential bullshit and miss all the true showstopping problems in most industries?

This world is amazing anything runs at all. The slightest addition of complexity is causing everything to fail now.

Modern computers are less reliable than ever, some companies have decided to REMOVE the pinhole bios reset (that has been around for 30 years) at the same time as things are buggier now and dont boot again until you physically unplug the bios battery deep inside and hard to get to.

Re: Solar panels + cold = A potential problem

#52

Post by xg15 »

beefnugs wrote: post #51
xg15 wrote: post #46

Earlier quoted context omitted.

This feels a bit like the logic behind "do not put hamster in microwave" warning labels. I think if you work with electrical or electronic systems in practice, you learn pretty quickly to respect tolerances and that data sheets are a map, not the territory. Also, electrical installations are usually seen as a field that should be done by trained personnel, not arbitrary laymen home owners. So I think the appropriate…

Actually if "you work with electrical or electronic systems in practice" you get pissed off at everything for how dumb it all is: 12V DC batteries are more like 14 nominal? AC wall plugs dip voltage when printers turn on, random equipment you arent even sure in the building can trigger UPSes based on unknown settings in the device? International standards and communication protocols mean nothing as "a standard" becau…

Spoken like a true professional!

Re: Solar panels + cold = A potential problem

#53

Post by _9ptr »

taneq wrote: post #47
uyzstvqs wrote: post #43

Sounds to me like someone is misrepresenting their products. A solar panel's VoC should be its maximum possible output in ideal conditions (open circuit). If that's under your product's maximum input voltage, it should be no problem. Ever. Is EcoFlow advertising a higher input voltage than their products can actually take, assuming most people won't actually reach it due to temperature inefficiencies? That'd be false…

What does “maximum possible voltage” mean for a solar panel? Do you include things like cloud edge effect (which increases incident light beyond direct sunlight?) What about installs with a nearby window reflecting light onto the panel? Do you include ultra-cold environments (which will reduce the resistance and therefore often increase voltage, although admittedly not, I think, Voc)?

Obviously you include everything, otherwise it wouldn't be a maximum. You can define a minimum temperature for this, of course, but the customer should know about it.

Re: Solar panels + cold = A potential problem

#54

Post by BertoldVdb »

sbierwagen wrote: post #24

I am surprised that open circuit voltage is specified at 25°C and increases dramatically as the temperature goes down. Seems backwards! I'm looking at the Ecoflow spec sheet right now and fair enough, it's got the open circuit voltage and then the Temperature Coefficient of Open Circuit Voltage (-0.35%/°C) right next to it. Great, guys, how about you go ahead and multiply those two numbers for me, since you're the on…

A solar panel is like a normal silicon diode. The voltage over the cell goes up drastically with lower temperatures. In cold climates crowbars are usually added.

Re: Solar panels + cold = A potential problem

#55

Post by numpad0 »

_9ptr wrote: post #53
taneq wrote: post #47

Earlier quoted context omitted.

What does “maximum possible voltage” mean for a solar panel? Do you include things like cloud edge effect (which increases incident light beyond direct sunlight?) What about installs with a nearby window reflecting light onto the panel? Do you include ultra-cold environments (which will reduce the resistance and therefore often increase voltage, although admittedly not, I think, Voc)?

Obviously you include everything, otherwise it wouldn't be a maximum. You can define a minimum temperature for this, of course, but the customer should know about it.

There's no theoretical maximum voltages for solar panels like there kind of is for batteries. They're just giant array of photodiodes and they just generate whatever voltage potentials proportionate to amount of lights received.

You could produce a "max voltage flying low earth orbit over Gobi with no shadows from Starlinks" value, but that's just the value for circumstantial most absurd situation you happened to have come up with, not a guaranteed theoretical maximum.

Re: Solar panels + cold = A potential problem

#56

Post by krisoft »

xg15 wrote: post #50
harvey9 wrote: post #48

Earlier quoted context omitted.

I have the impression these are consumer products so I would them to be designed to be installed by people who do not normally work with electrical systems. If they are only sold to tradesmen that would be different.

Yeah, it would be important to understand who the company is intending to sell to or do the installation. Though the lines are often blurred, because I guess most companies would like to sell directly to end customers, even if their product requires a professional to install. Even IKEA does this. You can go in and buy an electric stove and oven, grab them from the warehouse and take them home with you right there. Bu…

> Yeah, it would be important to understand who the company is intending to sell to or do the installation

You can do that by just reading the product page[1]. The delta pro, the equipment in question, looks like a plug-in appliance. It visually communicates that it is portable (by having a wheel and a handle) and by virtue of having a power lead connect to it it communicates that you can just plug it in. They further reinforce this by writing this: "Plug & Play home backup solution". "Easy installation with completely pre-wired Plug & play home backup solution" "The solution provides a convenient home battery system without rewiring or running dangerous extension cables through your home." "Plug directly into an AC wall outlet and make sure that the wall output current is more than 15A."

And on top of that the manual[2] makes no mention of needing an electrician.

In contrast an IKEA electric oven's product page[3] states this: "No plug is included. Installation to be carried out by a qualified installer." and then the manual[4] states "Installation, including water supply (if any) and electrical connections, and repairs must be carried out by a qualified technician."

But of course nobody reads the manual. The big difference is that one comes with a plug while the other doesn't.

1: https://us.ecoflow.com/products/delta-pro-portable-power-sta...

2: https://websiteoss.ecoflow.com/cms/upload/2022/10/12/1312845...

3: https://www.ikea.com/gb/en/p/mataelskare-forced-air-oven-ike...

4: https://www.ikea.com/in/en/manuals/matalskare-forced-air-ove...

Re: Solar panels + cold = A potential problem

#57

Post by emn13 »

xg15 wrote: post #46
teiferer wrote: post #25

Maybe they should just improve their product to make it more resiliant, rather than blaming customers for thinking that 148 V is below 150 V? Not everybody buying these has a Ph.D. in physics and if it says 148 V on the label and 150 V on the other label then it's your product that has a problem, not the customer. And no matter what happens, customer support should help the customer, not blame them.

This feels a bit like the logic behind "do not put hamster in microwave" warning labels. I think if you work with electrical or electronic systems in practice, you learn pretty quickly to respect tolerances and that data sheets are a map, not the territory. Also, electrical installations are usually seen as a field that should be done by trained personnel, not arbitrary laymen home owners. So I think the appropriate…

So on the one hand we have a product which isn't even remotely designed for the use case (hamsters), and during normal use shows obvious behaviour (cooking) that should imply risk to said hamsters. On the other side, we have a product designed to be installed in an electrical system, and shows no signs during normal use that it's installed unsafely, and where the advertised specs are not actually safe for normal usage.

Whether or not the company in this case shares some or most of the blame with novice users - the analogy is not a great one.

Re: Solar panels + cold = A potential problem

#58

Post by numpad0 »

geocar wrote: post #29
teiferer wrote: post #25

Maybe they should just improve their product to make it more resiliant, rather than blaming customers for thinking that 148 V is below 150 V? Not everybody buying these has a Ph.D. in physics and if it says 148 V on the label and 150 V on the other label then it's your product that has a problem, not the customer. And no matter what happens, customer support should help the customer, not blame them.

> Not everybody buying these has a Ph.D. in physics and if it says 148 V on the label and 150 V on the other label then it's your product that has a problem, not the customer. Idk. I don't have a PHD, but 220V sounds like 240V to me. I wouldn't do this. I feel like getting advice about how to wire up electronics should not be so hard. > Maybe they should just improve their product to make it more resiliant Adding "re…

> Idk. I don't have a PHD, but 220V sounds like 240V to me. I wouldn't do this.

220[Vrms] * 1.414 = 311[Vp-p] btw. HOW!?

Re: Solar panels + cold = A potential problem

#59

Post by amelius »

teiferer wrote: post #25

Maybe they should just improve their product to make it more resiliant, rather than blaming customers for thinking that 148 V is below 150 V? Not everybody buying these has a Ph.D. in physics and if it says 148 V on the label and 150 V on the other label then it's your product that has a problem, not the customer. And no matter what happens, customer support should help the customer, not blame them.

> make it more resiliant, rather than blaming customers

Yeah, this sounds very much like "you're holding it wrong".

Re: Solar panels + cold = A potential problem

#60

Post by abcd_f »

teiferer wrote: post #25

Maybe they should just improve their product to make it more resiliant, rather than blaming customers for thinking that 148 V is below 150 V? Not everybody buying these has a Ph.D. in physics and if it says 148 V on the label and 150 V on the other label then it's your product that has a problem, not the customer. And no matter what happens, customer support should help the customer, not blame them.

I read it as a problem with solar panel voltage going over declared threshold of 37v in certain meteo conditions.

That is the issue is with the wrong labeling of things that are being plugged into this vendor's device, not the vendor's own labeling.

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