Victron 100/20 smart solar

[MrNatural22]

As an experiment and had nothing else to do today
I Just connected three ecoworthy 200w bifacial panels in parallel to a Victron 100/20 smart solar mppt for two Valence 40ah 12v lifepo batteries connected in parallel for 80ah 12v
Looking at the app I was getting 8.6a from the panels and 20.2a from the mppt.
The Victron I know will limit output to 20a.
Does it cause harm if the amps are .2a over? I’m way under voltage limit at
As reported by the app or the Victron will just limit the charge.
Pretty sure I’m ok
I have panels in parallel for occasional partial shade on a rolling rack I can roll where needed works and rolls around the yard thru dirt and grass

easily.
Thanks

 

[sunshine_eggo]

Does it cause harm if the amps are .2a over? I’m way under voltage limit at

Not at all. 0.2A is 1% of 20A. I would assume it's an error, or just limits of the hardware, i.e., if you told me you were only getting 19.8A, I would still just assume either that's as accurate as the unit can be, or that particular arrangement of circuits peaks at 19.8A.

 

[pollenface]

I get 15.2a sometimes from a 75/15

 

[Chris O]

I just bought the same Victron SmartSolar Charge Controller MPPT 100/20 I am curious about the specifications on your Solar Panels.
=Rated Maximum Power
=Current at Pmax (Imp)
=Voltage at Pmax (Vmp)
=Short-Circuit Current (Iac)
=Open-Circuit Voltage (Voc)
=Maximum System Voltage
=Maximum Series Fuse Rating

I need to use the MPPT for both 12v and then disconnecting from that battery and connecting to 48v (Golf cart) occasionally
I was considering some old SUNTECH panels I can get for $35
(3 panels in series) and perhaps an additional 3 in series to boost Amps to (7.63+7.63)
Maximum Power Pmax=200W
Current at Pmax=7.63A
Voltage at Pmax=26.2V
Short Circuit Current = 8.12A
Open Circuit Voltage = 33.4
Maximum System Voltage = 600A
Maximum Series Fuse Rating = 20A

 

[Q-Dog]

I just bought the same Victron SmartSolar Charge Controller MPPT 100/20 I am curious about the specifications on your Solar Panels.
=Rated Maximum Power
=Current at Pmax (Imp)
=Voltage at Pmax (Vmp)
=Short-Circuit Current (Iac)
=Open-Circuit Voltage (Voc)
=Maximum System Voltage
=Maximum Series Fuse Rating

I need to use the MPPT for both 12v and then disconnecting from that battery and connecting to 48v (Golf cart) occasionally
I was considering some old SUNTECH panels I can get for $35
(3 panels in series) and perhaps an additional 3 in series to boost Amps to (7.63+7.63)
Maximum Power Pmax=200W
Current at Pmax=7.63A
Voltage at Pmax=26.2V
Short Circuit Current = 8.12A
Open Circuit Voltage = 33.4
Maximum System Voltage = 600A
Maximum Series Fuse Rating = 20A

Open Circuit Voltage (VOC) CANNOT exceed 100 for that controller. 33.4 X 3 = 100.2

You can do 2 in a string and 2 strings in parallel.

 

[sunshine_eggo]

I just bought the same Victron SmartSolar Charge Controller MPPT 100/20 I am curious about the specifications on your Solar Panels.
=Rated Maximum Power
=Current at Pmax (Imp)
=Voltage at Pmax (Vmp)
=Short-Circuit Current (Iac)
=Open-Circuit Voltage (Voc)
=Maximum System Voltage
=Maximum Series Fuse Rating

I need to use the MPPT for both 12v and then disconnecting from that battery and connecting to 48v (Golf cart) occasionally
I was considering some old SUNTECH panels I can get for $35
(3 panels in series) and perhaps an additional 3 in series to boost Amps to (7.63+7.63)
Maximum Power Pmax=200W
Current at Pmax=7.63A
Voltage at Pmax=26.2V
Short Circuit Current = 8.12A
Open Circuit Voltage = 33.4
Maximum System Voltage = 600A
Maximum Series Fuse Rating = 20A

Those are odd panels and not a good option for 48V. 3S is too close to 100V for safety. In warm conditions, you'd be okay, but below 25°C, you run the risk of blowing the 100V limit and killing the controller.

1 or 2S2P is fine for 12V. You need different panels for 48V, and you don't have a lot of options due to the 100V limit.

 

[pollenface]

I have a pair of 100/20 for running 2s 72cell arrays but i needed a 150/35 for my new 2s 96cell array.

Glad Victron prices have recently dropped

 

[sunshine_eggo]

I have a pair of 100/20 for running 2s 72cell arrays but i needed a 150/35 for my new 2s 96cell array.

Glad Victron prices have recently dropped

2S 72c is riding that line! I had 3S 72c on my 150V MPPT, and I swapped it out for a 250.

 

[pollenface]

2S 72c is riding that line! I had 3S 72c on my 150V MPPT, and I swapped it out for a 250.

I live in Perth, Australia, it rarely gets below 1c

Highest recorded voltages are 90.25v & 90.14v

 

[Chris O]

I used Victron's Spreadsheet (There web version had ZERO luck doing a 48v Panel solution) and found I could do either 12v or 48v with Rich Solar 200W RSM200 from Current Connected in a [3 in Series] [2 Parallel] configuration It does report the over 30% over sized for 12V but that's ok [Shows "Accepted] as I will potentially be changing back and forth between 12V RV system and 48V Golf Cart charging

Thoughts - do you trust the Victron tools? https://www.victronenergy.com/support-and-downloads/software (Excel at bottom of page)
web version that can't solve for 48v on MPPT 100/20 https://www.victronenergy.com/mppt-calculator


Rich Solar - https://www.currentconnected.com/product/rich-solar-200w-solar-panel/
Max Power 200W
Max Power Voltat 20.4V
Max Power current 9.80A
Open Circuit Voltage 24.3V
Short Circuit Current 10.2A

Below from the VICTRON EXCEL Spreadsheet tool, manually entered Rich Solar configuration into [Modules] tab.

 

[JoeHam]

My best guess on the 48V problem is this :

Your 48V nominal battery will be over 56V while charging.

At max temp your 3s panels will put out a minimum PV voltage of 51.8V if I’m reading your results correctly.

I believe the Victron needs to see 5V over charging voltage to function correctly.

Perhaps it will work at lower temperatures but certainly not at the max temperature calculation.

That would be the problem, right ?

 

[sunshine_eggo]

I used Victron's Spreadsheet (There web version had ZERO luck doing a 48v Panel solution) and found I could do either 12v or 48v with Rich Solar 200W RSM200 from Current Connected in a [3 in Series] [2 Parallel] configuration It does report the over 30% over sized for 12V but that's ok [Shows "Accepted] as I will potentially be changing back and forth between 12V RV system and 48V Golf Cart charging

For 12V this is easy.

The issue is that 51.8V min voltage at max temperature is well below the voltage needed to charge a 48V battery. Victron MPPT require +5Voc above battery voltage to start charging and +1-2V to continue charging once started.

Golf cart batteries likely need to be charged above 58V.

 

[Chris O]

I used Victron's Spreadsheet (There web version had ZERO luck doing a 48v Panel solution) and found I could do either 12v or 48v with Rich Solar 200W RSM200 from Current Connected in a [3 in Series] [2 Parallel] configuration It does report the over 30% over sized for 12V but that's ok [Shows "Accepted] as I will potentially be changing back and forth between 12V RV system and 48V Golf Cart charging

Thoughts - do you trust the Victron tools? https://www.victronenergy.com/support-and-downloads/software (Excel at bottom of page)
web version that can't solve for 48v on MPPT 100/20 https://www.victronenergy.com/mppt-calculator


Rich Solar - https://www.currentconnected.com/product/rich-solar-200w-solar-panel/
Max Power 200W
Max Power Voltat 20.4V
Max Power current 9.80A
Open Circuit Voltage 24.3V
Short Circuit Current 10.2A

Below from the VICTRON EXCEL Spreadsheet tool, manually entered Rich Solar configuration into [Modules] tab.

View attachment 206830

View attachment 206829

When I do this same calculation on the Victron WEBSITE, with "Custom Module" setting so I can manually input Voc, Isc, Vmpp, Impp, there is no MPPT 100/20 configuration that works.

 

[Chris O]

Thanks for the insights Sunshine_Eggo and JoeHam. I see the temperature issue for the 48V. If I use Victron's spreadsheet I can play with Max and Min Temperature If I bring the Max Temperature down to 97F, then the Min PV voltage goes up to 58.0V. The restrictions of this Victron MPPT 100/20 are really much more constraining than I realized since I am so new. Just in the past 24 hours with what I have learned I never would have bought it.... on sale for $89 wasn't a bargain. I may still get panels and use just for my 12V RV, but looks like there is no solution to really use this MPPT with a 48V battery charging at 58V.

 

[LakeHouse]

When I do this same calculation on the Victron WEBSITE, with "Custom Module" setting so I can manually input Voc, Isc, Vmpp, Impp, there is no MPPT 100/20 configuration that works.

Yeah, the panels are just all wrong for it. You need to have higher Vmp and run two in series, or lower Voc and run three in series. That particular Voc and Vmp combination doesn't work with a 100/20. You could use a 150/35 with three in series, or even four if you don't go below about -20C.

 

[sunshine_eggo]

When I do this same calculation on the Victron WEBSITE, with "Custom Module" setting so I can manually input Voc, Isc, Vmpp, Impp, there is no MPPT 100/20 configuration that works.

The 100/20 @ 48V is not a great general solution. 48V on ANY 100V controller is a major challenge (most don't support 48V).

Your only real option is to get 2X "24V" ~45Voc panels in series, and disconnect the array if it drops below freezing.

 

[Chris O]

I have a pair of 100/20 for running 2s 72cell arrays but i needed a 150/35 for my new 2s 96cell array.

Glad Victron prices have recently dropped

Can you tell me the brand and model of your 2 in series 72 Cell arrays? I am struggling to get the tools to give me options even for decent 12V performance, and the webtool won't give back anything for 48V battery using MPPT 100/20

 

[Chris O]

The 100/20 @ 48V is not a great general solution. 48V on ANY 100V controller is a major challenge (most don't support 48V).

Your only real option is to get 2X "24V" ~45Voc panels in series, and disconnect the array if it drops below freezing.

I may do that. I don't need to have it running 7x24x365 it's going to be used on 12V on the RV when we use it on property but don't start the generator, and would be used Fall, Spring, Summer (east Tennessee) to charge our LANDMASTER EV UTV (48V) Eventually we will have whole house solar with EG4 18k(2-3) or EG4 XP6000s (4-6 of them) .... but until we build and until we have larger solar I just needed a "easy simple solution" which of course is turning out to not be simple, and not be cheap, and not quick either

 

[Chris O]

For 12V this is easy.

The issue is that 51.8V min voltage at max temperature is well below the voltage needed to charge a 48V battery. Victron MPPT require +5Voc above battery voltage to start charging and +1-2V to continue charging once started.

Golf cart batteries likely need to be charged above 58V.

and the Battery Manufacture did state to charge at 58V for the 48V battery

 

[sunshine_eggo]

I may do that. I don't need to have it running 7x24x365 it's going to be used on 12V on the RV when we use it on property but don't start the generator, and would be used Fall, Spring, Summer (east Tennessee) to charge our LANDMASTER EV UTV (48V) Eventually we will have whole house solar with EG4 18k(2-3) or EG4 XP6000s (4-6 of them) .... but until we build and until we have larger solar I just needed a "easy simple solution" which of course is turning out to not be simple, and not be cheap, and not quick either

Even in freezing conditions, once the panels have been warmed by the sun, there's a good chance they'll be well above freezing, and they can be used on clear cold days.

and the Battery Manufacture did state to charge at 58V for the 48V battery

I was going off 14.5V/12V as a typical FLA charge voltage.