Classic 150 "input amps"

[ljane]

Hi there,

I have a question. I have:

    -nine 300W, 48V panels
    -Classic 150 CC -- without Whizbang Jr
    -three SimpliPhi 3.8 batteries (225Ah total)

It's all off grid (though I can plug into shore power to charge the batteries if necessary.)

I acquired this setup when I bought my house, so I don't know whether the CC and inverter settings were ever correct, but I recently realized many of them were off, so I've been working with the battery manufacturer to get things updated. The battery manufacturer says the CC setting for "input amps" should be "based on input charging source." I called Midnite Solar to ask for advice on this (I'm a real novice) and was told that the setting didn't matter. It's currently set to 42, so I asked whether that was an okay setting and was told yes but the rep would not explain why that was okay, or why the setting doesn't matter.

Can anyone explain this to me? Thanks!-Laura

[ClassicCrazy]

Hi there,

I have a question. I have:

    -nine 300W, 48V panels
    -Classic 150 CC -- without Whizbang Jr
    -three SimpliPhi 3.8 batteries (225Ah total)

It's all off grid (though I can plug into shore power to charge the batteries if necessary.)

I acquired this setup when I bought my house, so I don't know whether the CC and inverter settings were ever correct, but I recently realized many of them were off, so I've been working with the battery manufacturer to get things updated. The battery manufacturer says the CC setting for "input amps" should be "based on input charging source." I called Midnite Solar to ask for advice on this (I'm a real novice) and was told that the setting didn't matter. It's currently set to 42, so I asked whether that was an okay setting and was told yes but the rep would not explain why that was okay, or why the setting doesn't matter.

Can anyone explain this to me? Thanks!-Laura

It would help to know which voltage your battery system is at . I am guessing 48v with the three batteries wired in parallel ?
You link shows both a 24v and 48v model . But with what you said above guessing that the three 48v in parallel would be your 225 Ah.
The specs show max charge rate of 37.5 amps but I would think that would triple with three batteries although maybe bms is limiting factor. So go with what your battery manufacturer says.
Do you know how the nine PV panels are wired up ? I may guess 3 in series and 3 of those strings in parallel ?
There is a midnite string sizing calculator that would be helpful for you . You would need the info from the back of one of your PV panels to fill out the calculator.
Fill out this and get a screen shot of the results .
https://www.midnitesolar.com/sizingTool/index.php
I don't know why you would want to limit the input amps. Maybe that was someones attempt to  limit   output amps to the batteries.
But there is another way to limit output amps to the batteries without limiting the available amps to the rest of system ( like inverter).
Do you have a Whizbang installed on the system ?
It would help to know what that string sizing calculator says .
What are the setpoints  that battery manufacturer told  you to use ?

Larry 

[ljane]

Thanks for your response, Larry. Details inserted below.

It would help to know which voltage your battery system is at . I am guessing 48v with the three batteries wired in parallel ?

That is also my assumption. I reached out to the guy who sold me the house and installed the solar to find out for sure.

You link shows both a 24v and 48v model . But with what you said above guessing that the three 48v in parallel would be your 225 Ah. The specs show max charge rate of 37.5 amps but I would think that would triple with three batteries although maybe bms is limiting factor. So go with what your battery manufacturer says.

Yes, 48v. And I agree about the 37.5 amps * 3. That was why I called Midnite Solar. 112.5A is a lot different from the existing setting of 42. However, it looks like my inverter (Schneider Electric SW4048) limits the charge current to 45A, so maybe it's not that big a deal.

It does surprise me that the seller would use an inverter that has such low limits, but that's a different question.

Do you know how the nine PV panels are wired up ? I may guess 3 in series and 3 of those strings in parallel ?

Also my guess, and that's what I used for the sizing calculator. I'll update if the seller says anything different.

There is a midnite string sizing calculator that would be helpful for you . You would need the info from the back of one of your PV panels to fill out the calculator.
Fill out this and get a screen shot of the results .
https://www.midnitesolar.com/sizingTool/index.php

Results attached. There were two sets of specs -- one for test conditions and the second (I assume) for more realistic conditions. Both returned the same; only the test specs are attached.

I don't know why you would want to limit the input amps.

Yup, exactly. Maybe the inverter requirement described above?

Maybe that was someones attempt to  limit output amps to the batteries.
But there is another way to limit output amps to the batteries without limiting the available amps to the rest of system ( like inverter).

As above.

Do you have a Whizbang installed on the system ?

No.

What are the setpoints  that battery manufacturer told  you to use ?

Screenshot attached: "Size based on input charging source." That's why I'm a little unsure of myself. A full list for integrating the batteries with the Classic 150 is at https://simpliphipower.com/wp-content/uploads/documentation/phi-series/simpliphi-power-phi-battery-midnite-solar-integration-guide.pdf (p. 6).

Thank you again for your help. I'm pretty handy (just worked on my gas stove without blowing myself up), but solar is brand new to me, and I can't quite wrap my head around the electrical theory.

Laura

[ClassicCrazy]

Alt E has some good beginner solar videos on their youtube channel that can explain  PV series , parallel , etc .
Also a Will Prowse has some beginner videos about solar.
What voltage , absorb time, ending amps ? , float  setpoints did the battery manufacturer say to use in your Classic ?
The question I would have for the the battery manufacturer is do you limit the current to 37.5 amps for all three batteries or can it go higher ?
From the Classic sizing tool that you posted your system will only put out max of 46.9 amps to batteries .

You have a few things mixed up .
You need to ask the battery manufacturer about limits of charging current to batteries - not midnite.
If they say there is a limit of 37.5 amps then Midnite has a way to limit that current .
You also are mixing up the inverter battery charging amps , with the amount of power that the inverter can supply to power loads in your house.

I recommend you get a Whizbang installed on your system . It is the best way to really know the real amount of available power in the batteries and if what is going into them is the same amount coming out of them.  You would need to install a shunt in the negative cable that goes to the battery and the Whizbang mounts on that. You may want to have an electrician or solar installer put that in since you need to power everything down,  then crimp on appropriate terminals to fit the shunt. And depending on your setup you need to find the proper place to mount the shunt in your DC electrical box - no idea what you have there.

Larry

[ljane]

Alt E has some good beginner solar videos on their youtube channel that can explain  PV series , parallel , etc .
Also a Will Prowse has some beginner videos about solar.

Cool, thanks. I'll check them out.

What voltage , absorb time, ending amps ? , float  setpoints did the battery manufacturer say to use in your Classic ?

voltage - 56V (assuming you mean absorb voltage???)
absorb time - 6 min.
ending amps - 2% of capacity, so 4.5A, but according to the battery folks, "3. End Amps settings only work when the “Midnite Whiz Bang Jr & 500A/50mV shunt” are installed," so this is n/a for me.
float - 54V

The page from the battery manufacturer is attached with additional settings

The question I would have for the the battery manufacturer is do you limit the current to 37.5 amps for all three batteries or can it go higher ?

I believe it can go higher. That was part of my reason for questioning it and why I called MS. I imagine the batteries would allow up to 37.5 * 3 = 112.5, but that is so much higher than the 42A that was already set, that I wanted to make sure I wasn't going to destroy anything by changing it. But I could not get an answer of why it didn't matter.

From the Classic sizing tool that you posted your system will only put out max of 46.9 amps to batteries .

So it probably doesn't matter than I can output 112.5??

You have a few things mixed up .
You need to ask the battery manufacturer about limits of charging current to batteries - not midnite.

See above. But I may ping the battery folks again, since they've been super helpful.

If they say there is a limit of 37.5 amps then Midnite has a way to limit that current .

I'm pretty sure theat is not the limit, but that's good to know.

You also are mixing up the inverter battery charging amps , with the amount of power that the inverter can supply to power loads in your house.

Probably, ha ha! I'm pretty lost in this maze of amps and volts! Still trying to wrap my head around it all.

I recommend you get a Whizbang installed on your system . It is the best way to really know the real amount of available power in the batteries and if what is going into them is the same amount coming out of them.  You would need to install a shunt in the negative cable that goes to the battery and the Whizbang mounts on that. You may want to have an electrician or solar installer put that in since you need to power everything down,  then crimp on appropriate terminals to fit the shunt. And depending on your setup you need to find the proper place to mount the shunt in your DC electrical box - no idea what you have there.

I will consider this. Know an electrician in the Philly/NJ area that knows solar? I've had some trouble finding one. Haven't reached out to solar installers yet, but that's next on my list.

Thank you again for your help! Feel free to let me know what else I've messed up above!
Laura

[ljane]

Missing attachment enclosed

[ClassicCrazy]

Missing attachment enclosed

See note 2 at the bottom of the sheet - and ask battery folks to clarify that.
( I think it means take the 37.5 and multiply by 3  - but ask them ).

Anyway you won't ever get too close to the max battery charging limit out of your pv according to the Classic String calculator that you posted.

It might help you to draw out your system as a pictorial  block diagram and you can draw the wires between best you can follow them.
Then as you understand your system you can fill in some of the specs.
see page 47 to 49 of this manual for example of what I am talking about .
https://www.midnitesolar.com/pdfs/10-268-1_REVT_Kid_Manual.pdf

installing the Whizbang isn't too difficult for someone to do .
Here are the parts you need
https://www.solar-electric.com/midnite-solar-whiz-bang-jr-current-sense-module.html
https://www.solar-electric.com/midnite-solar-shunt.html
and this would help with install too but might not be needed
https://www.solar-electric.com/midnite-solar-shunt-busbar.html
you would also need two crimp terminals to fit the shunt  and which ones to get depends on the gauge size of wire used.
For anyone installing the shunt - the important thing is that on one side of it goes the wire to negative battery terminal . The other side of the shunt has all the other negative connections. Depending on your original installation that is why I recommended the third part in that list.
The Whizbang install is well worth the investment because it can tell you the percent of power left in the batteries, and you can also use the ending amps setting that the battery manufacturer has in their setup sheet.

Larry

[FNG]

Typically input amps is never used, That is for the classic to limit its charging on the amperage on the pv side but as you have an MPPT it steps that down. I would set Input amps to 99 and get a WBjr and shunt installed. If you need to limit the classic below the 84 ish amps it can produce you want to look at OUTPUT AMP LIMIT. Now this all said you also need to make sure the installer didnt put smaller wire or breakers (You have all the proper breakers I hope) and setting this limit higher could trip the breakers or melt some wire. I suggest sharing good pictures of every aspect of the system here and we can then assist further

Ryan

[boB]

FYI:

Classic input amps limit setting (99A default) was added for micro-hydro applications.

[Jwalter]

Has anyone verified with Simpliphi that the charge rate can go up with each subsequent battery added to the system? (i.e. should be capable of 75A charge/discharge with 2x Phi 3.8-48v, or 112.5A w/ 3x?)

So I'm happy with the batteries, but Simpliphi's instructions (including the integration sheets) are not very clear about this.

I have a similar setup using a CL200, WBjr, and 2x Phi 3.8 batteries on 48v system.