Parallel panels different Pv

[PancakeBill]

I have two 250 watt panels mounted on the roof. 33v each. In par the panels capable of providing 500 watts at the 33 volts. But, I have a 200 watt folding panel that is at 23 volts. If the folding and the roof are all connected in parallel, I see that as 700 watts. These feed into a Bluetti Power Station. However what will the voltage show me? Resistors in par will give average resistance, but voltage? fuzzy on that one, and will it make a difference to the charging system?

current is on 250 8.27. on 200 9.92

 

[PancakeBill]

Finally found a good source.

Voltage is limited by lowest in circuit. So my 2 at 33v and 1 at 23 volts will be 23 volts.

The amps will add so 9.92 + 8.27 + 8.27 = 26.46 amps total

amps 26.46 * volts 23 = 608 .58 watts

Now all these numbers are on the optimal side YMMV

Is my logic correct?

 

[Primerump]

yes, basically in a nutshell..
when paralleling dissimilar panels, the voltage will be of the lowest panel and the currents will sum, generally the max wattage will be the combined current times the lowest voltage.
when you series them, the voltages add but the current will be of the lowest panel.
your good source was already here.. lol. just pm me.

 

[PancakeBill]

Here is a question, looking around I see solar disconnect switches, at what point are these needed, or just disconnecting sufficient?

I am curious what panels are producing when the controller is no longer accepting power. Just a curiosity thing. Seeing a number of inline indicators, but not sure if that does what I want, labelled source and load, if there is no load will it still show, or is it more like a shunt?

 

[Primerump]

Here is a question, looking around I see solar disconnect switches, at what point are these needed, or just disconnecting sufficient?

a solar disconnect is usually required by NEC code for residential systems to disconnect the array for safety reasons ( ie: a 500V array not electrocuting fire fighters etc.. ). for an RV where there are no codes to speak of, it's a good addition to isolate the array when working on the system. the lower voltage is usually not considered an issue unless you have series panels that exceed 50V. I always mandate one, it's so much more convinient and a simple way to isolate the array. disconnects MUST be rated for 1.25 times the working voltage and be DC rated. an AC residential breaker will not do, period..

I am curious what panels are producing when the controller is no longer accepting power. Just a curiosity thing. Seeing a number of inline indicators, but not sure if that does what I want, labelled source and load, if there is no load will it still show, or is it more like a shunt?

Panels are a current source, power only flows when there is a current sink, ie: a controller/battery load.
when your batteries approach 100%, the panel current will decrease and the voltage will increase. when no current is drawn the voltage will reach the Voc ( open circuit voltage ).

 

[Lou Schneider]

I'd get a separate MPPT controller for the folding panel and combine it's output with the main system. This will give you full output from all of the panels.

 

[PancakeBill]

I'd get a separate MPPT controller for the folding panel and combine it's output with the main system. This will give you full output from all of the panels.

Not sure what that would do? Right now it is feeding into the power station. Not into batteries.

 

[Lou Schneider]

Not sure what that would do? Right now it is feeding into the power station. Not into batteries.

You didn't say that - just that you wanted to put it in parallel with the roof panels.