[sbierwagen]

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 ones writing the fucking spec sheet? It's like if car battery manufacturers only specified a cranking amps number, and told you to figure out cold cranking amps yourself.

[crote]

> how about you go ahead and multiply those two numbers for me

What are you going to fill in for the third number, though? With an open-circuit voltage of 37.10V at 25°C and a coefficient of -0.35%/°C it can theoretically go up to 75V at absolute zero. And that open-circuit voltage is with an irradiance of 1000 W/m2, should we also account for the possibility of someone building a heliostat around it?

There's no one-size-fits-all number they could possibly quote. It'll always depend on the environment, because that's just how the physics work. The best you can do is provide a figure for the standardized testing environment and the relevant coefficients - which is exactly what they are doing.

[Dylan16807]

At merely freezing, that solar panel would hit 40 volts. In the coldest point of the US in a typical winter, it would get up to about 42 volts. At the record minimum temperature, in either montana or alaska since they have similar records, you'd get up to about 48 volts.

42-48 is not a big enough range to give up over. My impulse is to arbitrarily pick -40 and say the normal max voltage is 45.5 degrees. Now it's nice and obvious that you can only hook up 3 to a 150 volt input, and you'll have a 9% margin of error left over. On that "first cold and sunny day" you'll output 120 volts instead of 160.

And no don't worry about a heliostat.

[teiferer]

> Great, guys, how about you go ahead and multiply those two numbers for me, since you're the ones writing the fucking spec sheet?

No time. Busy writing blog posts blaming customers.

[Dylan16807]

You think ecoflow is responsible for this website and is pretending not to be?

[BertoldVdb]

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.