Victron 100/50 question...adjustable battery charging current?

[Flunkyboi]

The best I understand an MPPT charge contoller, the input voltage/amps from the PV is efficiently reproportiined to the lower voltage of the battery system. The max current the 100/50 is 50 amps.

I checked each of my six array panels on a cold day a couple of weeks back. Voltage check was open circuit and the voltmeter read 45-46vdc. This was higher than the panels listed "max power voltage" (41.1v) and lower than "open circuit voltage" (49.1v)

"max power current" is 9.86a. "Short circuit current" is 10.37a. The wattage listed is 405.

I assume if these will make a loaded current of say an even 10amps-ish, two panels in series 45+45=90v will be OK for the 100v max, but proportioning that 90 volts to 13 volts at the battery gives a ratio (90 panel volts ÷13 battery volts =) a 6.92 multiplier for amps. 6.92 × 10= 69.2 amps. That will smoke that new Victron 100/50, correct?

Is my math right?

 

[ricardocello]

I assume if these will make a loaded current of say an even 10amps-ish, two panels in series 45+45=90v will be OK for the 100v max, but proportioning that 90 volts to 13 volts at the battery gives a ratio (90 panel volts ÷13 battery volts =) a 6.92 multiplier for amps. 6.92 × 10= 69.2 amps. That will smoke that new Victron 100/50, correct?

The 100/50 will safely limit its output current to 50A, no smoking involved.

Also, 90V is pushing the 100V limit pretty close, and in cold weather you might have a problem with smoke.

 

[Flunkyboi]

The 100/50 will limit its output current to 50A, no smoking involved.

Also, 90V is pushing the 100V limit pretty close, and in cold weather you might have a problem with smoke.

So it will self limit current output to protect itself, but 101v on a bright, cold day can kill it?

 

[ricardocello]

So it will self limit current output to protect itself, but 101v on a bright, cold day can kill it?

You’ve summarized that beautifully and correctly.

Obviously, they get a little margin above 100v, but there is no quicker way to kill an MPPT than by going over on volts.
This is a common topic on the forum, there is no good way to add protection to handle it.
Midnite has HyperVOC which shuts down if you overvolt. That’s the only one with protection I am aware of.

 

[ricardocello]

I checked each of my six array panels on a cold day a couple of weeks back. Voltage check was open circuit and the voltmeter read 45-46vdc. This was higher than the panels listed "max power voltage" (41.1v) and lower than "open circuit voltage" (49.1v)

"max power current" is 9.86a. "Short circuit current" is 10.37a. The wattage listed is 405.

A few important points:

You have a total of 6 x 405W = 2430W of panels (at STC)
Your MPPT can only deliver 700W charging at 12V nominal. so you are way over paneled.

The Voc is 49.1V. You really shouldn’t put two of those in series with the 100/50, it will blow up during a cloud edge in cold weather.

You could safely do a 1s5p configuration with the 100/50, keeping total Voc and Isc under the limits.
It will still be way overpaneled, but will deliver power for longer periods during the day.

 

[ricardocello]

Also, try this:

MPPT Calculator - Victron Energy

MPPT Calculator - Victron Energy

www.victronenergy.com

 

[740GLE]

For a 100v SCC, ideally look for a panel VOC under 40v if you want to run 2s configurations.

I believe there are quite a few 108 half cell panels around 390-430w have have VOC in the 35-40v range.

 

[Flunkyboi]

A few important points:

You have a total of 6 x 405W = 2430W of panels (at STC)
Your MPPT can only deliver 700W charging at 12V nominal. so you are way over paneled.

The Voc is 49.1V. You really shouldn’t put two of those in series with the 100/50, it will blow up during a cloud edge in cold weather.

You could safely do a 1s5p configuration with the 100/50, keeping total Voc and Isc under the limits.
It will still be way overpaneled, but will deliver power for longer periods during the day.

The six on my array are not going to feed this little Victron 100/50. Right now, I just want to use the little Victron (and a panel or two) to bring four brand new 12v 100ah batteries up to full state of charge, one at a time.

Once they are all up, they will be seriesed to make a 48v bank. I will then series all six of the panels and install a new EG4 3000w All in One.

I do not own one of those fancy Lifepo4 fast chargers.

I'll just tie a single panel to feed the Victron for this first job for right now. Once the 48v bank is being fed by the EG4 3k, the Victron will go to a camper project. It will be 12v.

 

[Flunkyboi]

A few important points:

You have a total of 6 x 405W = 2430W of panels (at STC)
Your MPPT can only deliver 700W charging at 12V nominal. so you are way over paneled.

The Voc is 49.1V. You really shouldn’t put two of those in series with the 100/50, it will blow up during a cloud edge in cold weather.

You could safely do a 1s5p configuration with the 100/50, keeping total Voc and Isc under the limits.
It will still be way overpaneled, but will deliver power for longer periods during the day.

I assume "1s5p" means "one string of 5 in parellel". If the max wattage the 100/50 can put out is 700w I guess just two 400 panels in a parallel string will be OK?

 

[ricardocello]

I assume "1s5p" means "one string of 5 in parellel". If the max wattage the 100/50 can put out is 700w I guess just two 400 panels in a parallel string will be OK?

Yes, two in parallel should work very well.

 

[Brucey]

For a 100v SCC, ideally look for a panel VOC under 40v if you want to run 2s configurations.

I believe there are quite a few 108 half cell panels around 390-430w have have VOC in the 35-40v range.

The Hyperion 395/400W bifacials are perfect for this with voc at 37V.

 

[Q-Dog]

Even though the Victron can output 50 amps, you can limit it in settings to output less than that.

 

[Flunkyboi]

Even though the Victron can output 50 amps, you can limit it in settings to output less than that.

That is good to know. I'd not discerned that from from YouTube how tos or from the nonexistent manual that did not come with the unit.

I made headway today. Got two wired in to feed the Victron in prep for charging the 12v batteries, each one, one at a time. I may have it all ready by tomorrow's sun. I check the weather report....cloud and storms coming...lol!

 

[Flunkyboi]

OK, I might actually be able to start using this 100/50 unit this weekend. Goal is to full charge all four 12 v 100ah batteries, one at a time using two of my six panels.

They already came partially charged. This first one has 13.6v on my voltmeter. Do I need to just start charging or do I need to fully discharge each before and then let the Victron charge it fully?

These will be strung in series (48v) after a full charge.

 

[740GLE]

How are you planning on wiring the panels to the SCC? Parallel?

With a published VOC of 49v I’d stick to parallel.

 

[Flunkyboi]

Two 400w in parellel

 

[Q-Dog]

from the nonexistent manual that did not come with the unit.

This puzzles me as I have a stack of Victron manuals from all the blue stuff I have bought.

All Victron product manuals are available on the www.victronenergy.com web site. This should be the link to yours:

https://www.victronenergy.com/upload/documents/Manual_SmartSolar_MPPT_100-30__100-50/29694-MPPT_solar_charger_manual-pdf-en.pdf

 

[chrisski]

This puzzles me as I have a stack of Victron manuals from all the blue stuff I have bought.

That is my experience also, and I have a 100/50 in addition to five other Victron devices.

I wonder if the no manual meant a resale by the vendor of a returned item or perhaps Victron is doing what other manufacturers do and have a user download a manual if interested.

 

[740GLE]

I don’t think my 100/50 came much more that a quick set up guide not much bigger than a business card.

Not that I read or hold onto manuals.