Mismatched panels, Do I have this right?

[brianjonesphoto]

I’m upgrading the solar capacity on my camper. I found a deal on a couple 320w panels yesterday. I have 2x100w panels now. I’m trying to figure out if I should keep the 100’s or not.

The 320 panels are 36v and the 100 are 20.4. If I’m understanding everything correctly I could parallel the 320’s with the 100’s in series for 3 parallel legs. I would loose about 12% from the 100 string because of the voltage drop to 36v. I would need to fuse all 3 leg.

I’m running a Victron 100-50. There is a single pair of 8awg conductors going though the roof to the electrical bay. Adding another set isn’t practical.

Thanks.

320w specs
Imp 8.85
Vmp 36.2
Voc 44
Isc 9.6

https://www.canadiansolar.com/wp-content/uploads/2019/12/Canadian_Solar-Datasheet-HiDM_CS1H-MS_EN.pdf

100w specs
Imp 4.91
Vmp 20.4
Voc 24.3
Isc 5.21

https://store-fhnch.mybigcommerce.com/content/RNG-100D-SS/RNG-100D-SS-G3%20Datasheet.pdf

 

[sunshine_eggo]

I’m upgrading the solar capacity on my camper. I found a deal on a couple 320w panels yesterday. I have 2x100w panels now. I’m trying to figure out if I should keep the 100’s or not.

The 320 panels are 36v and the 100 are 20.4. If I’m understanding everything correctly I could parallel the 320’s with the 100’s in series for 3 parallel legs. I would loose about 12% from the 100 string because of the voltage drop to 36v. I would need to fuse all 3 leg.

Yes, and I would consider putting blocking diodes on each string to prevent backflow.

I’m running a Victron 100-50. There is a single pair of 8awg conductors going though the roof to the electrical bay. Adding another set isn’t practical.

Thanks.

320w specs
Imp 8.85
Vmp 36.2
Voc 44
Isc 9.6

https://www.canadiansolar.com/wp-content/uploads/2019/12/Canadian_Solar-Datasheet-HiDM_CS1H-MS_EN.pdf

100w specs
Imp 4.91
Vmp 20.4
Voc 24.3
Isc 5.21

https://store-fhnch.mybigcommerce.com/content/RNG-100D-SS/RNG-100D-SS-G3%20Datasheet.pdf

Given the numbers, the 2X 100 in parallel nearly equals the Imp of the 320W, so if you paralleled the two 100W in series with ONE 320W, you would have negligible losses, but no option for a second 320W.

 

[Quattrohead]

KISS just swap em out.

 

[TomC4306]

Three viable options.