Rate this 200w panel compared to two renogy 100w panels

[Etzu]

The Recreational Vehicle uses how many
batteries at what Voltage and Amp-hours sizes ?

At the moment I have two 12v 125ah batteries in parallel. Eventually I'll increase the side of the battery tray to either accommodate two more. or swap to two 6v batteries in series.

[Etzu]

With mppt the higher the imp volts it has to down convert the less efficient it will be. With 2 100 panels 38 or so to 12 is less efficient than the 200 watt 21 to 12. The loss would be in heat in the controller. And if your gonna later want 300 watts keep all the panels the same. Different imp vmp panels cost you power also.

Ok I think this is the answer I was looking for. So the single 200w panel I was originally looking at would be more efficient than using two 100w panels. Thank you.

[Mike90250]

Pv? Let's pretend I'm 5.

PV = Photo Voltaic as in PV panel

[SunEagle]

At the moment I have two 12v 125ah batteries in parallel. Eventually I'll increase the side of the battery tray to either accommodate two more. or swap to two 6v batteries in series.

Well here is the bad news. With 2 12v 125Ah batteries wired in parallel you will need about 20 to 25amps of charging. That calculates to about 300 watts (25a x 12V = 300w) for a 12v battery and a 30 amp MPPT CC. So it looks like you will need that 3rd 100watt panel to keep those batteries happy.

[Ho jo]

Fwiw if you use 100 watt renogy panels get the latest slim design. They are lower vmp and higher imp. They gave me a couple more amps vs 18.9 5.29 old style panels on a 300 watt system. But use only on mppt controller. Imo vmp on the slims are to low for parallel with pwm in 90f temps.