MPPT Solar Regulator - Duo?

[multihullsailor6]

Due to space restrictions on my cat "Burnout" I have now fitted 2 x 2 flexible solar panels of different sizes port and starboard, i.e 1 x 68Wp and 1 x 34 Wp port and starboard. I have today been informed by a fellow sailor that I cannot wire them in parallel as I had planned as they are of different sizes and thus different electricity. I would thus need four solar panel regulators or two with twin inputs.

I have looked at two catalogues but have not come across a MPPT solar panel regulator with twin input - do they exist?

[noelex 77]

Originally Posted by multihullsailor6

Due to space restrictions on my cat "Burnout" I have now fitted 2 x 2 flexible solar panels of different sizes port and starboard, i.e 1 x 68Wp and 1 x 34 Wp port and starboard. I have today been informed by a fellow sailor that I cannot wire them in parallel as I had planned as they are of different sizes and thus different electricity. I would thus need four solar panel regulators or two with twin inputs.

I have looked at two catalogues but have not come across a MPPT solar panel regulator with twin input - do they exist?

If the Vmpp are similar ( say within 0.5 v ) you can wire them in parallel. A bigger issue is likely to be that often port and starboard often experience different sun and shade altering the MPP.
This will mean the maximimum performance would be with 4 regulators, one for each panel, but in practice a single regulator will work OK
There are no regulators with 2 inputs, but you can use multiple regulators . The gains from having extra regulators will be small however.

[Pete7]

Roger, yep those electrons will be different sizes from different sized panels.

Now back the real world, ignore the person that gave you that advice, wire the panels together and charge the batteries.

Pete

[senormechanico]

You're fine as long as you don't wire different panels in series.
Parallel works fine in my case.
2 Aurinco 100 watt, and one SolarBlvd 120 watt all in parallel with a BlueSky MPPT.

The open circuit parameters are similar, 22 vs 21.6 volts.
Pmax voltages are 18 vs 17.6 volts.

[Wyoming pirate]

Correct me if I'm wrong, but you have a 68w panel and a 34w panel? if so, that is like 6.5 amps max output. if you are using more power than they can input in a day, which you probably are, do you need a charge controller?

[callmecrazy]

You could use a non-mppt charge contoller. The cheap duo I have works great, and I know morningstar also makes one. the morningstar is a high quality pwm controller...

or you could use 2 mppt controllers instead of four. 1 for the 68w panels and one for the 32w panels. Just have to route the wiring appropriately. Their locations make little difference except the wiring will be crossed at some point.

Or, you could consider wiring all them in series to a more substantial controller.

[callmecrazy]

sorry, I misread... You're looking for dual inputs, not dual outputs.... Gotcha.

You could still use 2 controllers instead of 4 if you wire each of the two similar panels in parallel to individual single input controllers.