Connecting different sized solar blankets to solar controller

Silveredition

Active Member
G'day all
I have just purchased a Victron 75/15 MPPT Solar controller.
I have a Kings 120W solar blanket that I am intending on connecting to the Victron, but was wondering if I purchased another solar blanket of a different size if I could connect both solar blankets to the Victron at the same time?

As a separate question - if the above is okay, would the Victron be able to have the 120W and a 200W conntected to it at the same time??

Thanks

Drew
 

Petunia

Well-Known Member
if I purchased another solar blanket of a different size if I could connect both solar blankets to the Victron at the same time?

Simple answer -: Yes, you could depending on size?

Complicated answer -: Depends on your second question?

As a separate question - if the above is okay, would the Victron be able to have the 120W and a 200W conntected to it at the same time??

Simple answer -: No for parallel wiring, Yes for series, with no gain in amperage, but a gain in voltage for a long run of cable.

Complicated answer -:

A 75/15 Victron ...... I take to be 75volts and 15amps, therefore-: 120W divide by 18.5V = 6.49A ..... plus [in parallel] a 200W divide by 18.5V = 10.8A ........ totaling 17.29A, thus: exceeding the 15A rating of the Victron.

120W + 200W in series = 37V ......... 240W divide by 37V = 6.49Amp [series wiring will always be the lower value in watts times the number of panels]

Conclusion -: A second panel wired parallel should not exceed [15A - 6.49]........ 8.5A, or [18.5V x 8.5A]........ 157.25Watts....... given the closest value may be 120W, my opinion is, [based on theory] 2 x 120W panels would work in parallel.

:cool:
 
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Silveredition

Active Member
Simple answer -: Yes, you could depending on size?

Complicated answer -: Depends on your second question?



Simple answer -: No for parallel wiring, Yes for series, with no gain in amperage, but a gain in voltage for a long run of cable.

Complicated answer -:

A 75/15 Victron ...... I take to be 75volts and 15amps, therefore-: 120W divide by 18.5V = 6.49A ..... plus [in parallel] a 200W divide by 18.5V = 10.8A ........ totaling 17.29A, thus: exceeding the 15A rating of the Victron.

120W + 200W in series = 37V ......... 240W divide by 37V = 6.49Amp [series wiring will always be the lower value in watts times the number of panels]

Conclusion -: A second panel wired parallel should not exceed [15A - 6.49]........ 8.5A, or [18.5V x 8.5A]........ 157.25Watts....... given the closest value may be 120W, my opinion is, [based on theory] 2 x 120W panels would work in parallel.

:cool:
Thanks Petunia for both the simple and complicated answers! I have done a bit of research today and learnt a lot because of the time you took to reply!
Drew
 

Buxter

Well-Known Member
I run 2 x 125 watt blankets into a Y connector and Anderson plugs, then single feed it into my MPPT controller
Works well but I do no exceed 10 amps into my 30amp controller
No Issues at all.

Gotta look at the output in amps for both panels.
Maybe go up a bit higher for the Controller.
Vitron do a 20 amp controller, therefore you will not be flogging the controller
Hope this makes sense ?
 

Silveredition

Active Member
I run 2 x 125 watt blankets into a Y connector and Anderson plugs, then single feed it into my MPPT controller
Works well but I do no exceed 10 amps into my 30amp controller
No Issues at all.

Gotta look at the output in amps for both panels.
Maybe go up a bit higher for the Controller.
Vitron do a 20 amp controller, therefore you will not be flogging the controller
Hope this makes sense ?
Thanks Buxter,
Maybe I should have ordered the 20! Too late now, but I will do what I need to end up with a set up that has a max of 15 amps and 75v...
 

Triton14

Well-Known Member
Hi guys, tagging in here.

Looking for input here on circuit breaker size.

If I was installing a Victron 100/30 with say a 250W solar panel what size breaker would I put between the controller & a 140AH AMG battery?
 
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