The one advantage I can see of doing 2P2S (i.e. you create TWO 12V batteries of 200Ah) is that the two batteries in parallel will be balanced between the two of them. There can still be an imbalance between those two batteries in series. Where if you had a 2S2P, there can be an imbalance...
I did a bit of reading on the subject and it's thick with (protective if burdensome) bureaucracy.
Here is my series of links and notes. This is just a copy of my personal summary notes so it might not be as polished as could be.
But to answer your questions, off the top of my head from what I...
I heard by from MPP (they are REALLY good at responding to email fast!).
I asked them what the short-circuit current limit (ISC) was on the LV2414 and they said:
With my configuration (see above), I currently have an ISC of 50.22A (with 6 strings in parallel).
With the 80Amp headroom, I could...
This is the last part of my post with my notes regarding the ARC Fault Protection
My ARC Fault Protection NOTES:
NEC 2017 / 2020 requires ARC fault protection with PV systems operating at more than 80V
NOTE on Arc Fault Circuit Interruption (AFCI) NEC requirements.
Any PV...
Good point... the higher profile DOES get a lot of attention. No permits. This is totally OFF grid. And when something is not PERMANENTLY attached, they have stupid rules where they don't regulate it LOL.... Mine are not attached AT ALL :)
I DID comment that these were my Gypsy panels :-)...
I head back from the MPP folks who btw have been SUPER helpful and fast to respond.... We are talking 3 email responses from them in 1.5 hours, the first withing 15 min of my initial inquiry!
They essentially say the same thing as Sunshine_Ego: If you respect the VOC and lsc, then you're...
Really!?!?!?
$50/panel? That is ... well, ridiculous, insane... I'd have to think of other negative attribute to describe my feelings toward such requirements LOL
BTW: Do you (or anyone reading this) have a link to an online version (or PDF) of the NEC 2017 and/or 2020 ...
No worries.
That thing doesn't look like it's running anywhere.
I sell one other item (that's also not moving fast) that is in my experience invaluable... I have one extra thermal camera. When you build your DIY solar system and you want to test periodically for any hot spot in your system (any...
I also emailed Victron, Eg4, Signature Solar (asked about EG4 3K and 6000XP) and Current Connected (asked about EG4 6000XP and Victron).
I heard back. from
Victron: Please talk to a reseller (not impressed!)
EG4: Haven't heard back yet
CurrentConnected: Haven't heard back yet
Signature Solar...
Yes, I effectively have 6 parallel strings of 2 panels (62V per string), coming into a PV bus bar. Each string is 15A fused.
I also sent an email to MPP (as well as Victron and Eg4 to how their systems respond to over paneling).
I took advantage of SanTan Solar's holiday sales onused panels...
Partimewages,
I do appreciate the NEC specifications to help keep us safe.
But not so much the bureaucracy that comes with it.
Basic things like the NEC not being readily available for download in PDF (laws and regulations imposed on the citizenry should always be available for free (and I don't...
The input voltage is 12V
Sorry for the late response.. I realize that the forum was not sending me notifications :-(
I include below photos of the user manual.
It's not super useful.
But I did test the inverter with a Lifepo4 battery (pretty standard stuff) so I expect it works from 10 to...
I have a MPP 2424-LV-MSD all in one inverter.
When all is connected (solar PV, input AC and output AC), all is good and works as expected.
BUT when I disconnect AC (load and neutral are disconnected by a breaker/switch but the ground is permanently connected... as should be), then using a 3 LED...
I recently purchased a MPP 2424LV-MSD
Lovely starter unit... Now I wish I had gotten a more capable EG4 3K LOL. Live and learn!
The unit has a restricted VOC of 150V. and operating voltage of 30-80V... limiting me to setting my (used) 240W Trina panels
in strings of 2 panels (about 60V...
Thanks for putting the Victron and MPP information linked in one post.
In short: Rexpect max VOC and max Isc on your Solar Controller. Victron publishes their max lsc. For MPP I had to ask.
I just heard back from Signature Signature solar and they clarified that EG4 already publishes specs...
Ahhh yes, good point.
The module you listed below (which also takes care of shading) seems interesting and the cost is more affordable ($26).
Adding $26/panel is not that big a deal when you install new 400w+ panels.
But when you create a setup with smaller used panels, it makes a big...
Thanks, I appreciate the feedback and agree with you.
I am using #6 AWG for grounding all my panels so I will simply tie in to that. No amount of sun wind and rain will rip a #6 AWG copper wire :-)
I'm delighted to hear it!
I would *assume* the more remote/rural, the higher the chances that bureaucracy might be a tad lighter.
Unfortunately it doesn't appear to be that easy in San Diego County :-(
BACKGROUND:
I have 4x LiTime 12V 100AH batteries and my MPP inserter runs at 24V.
It looks like most setups configure things in 2S2P (two strings of 2x12v inseries) and the two strings connected in parallel.
Recently I have been learning about the problems that unbalanced 12v batteries in...
Using 4x 12V 100Ah LiTime LifePo4 batteries to build a 2S2P 24v batteries I am now looking for something to monitor
that the batteries are string nicely balanced.
I got a pack of cheap volt meters:
https://www.amazon.com/Battery-Indicator-Voltage-Capacity-Lithium/dp/B09JSJDY8N/
But it turns...
You can also look directly at the LiTime website and purchase a "Like New" battery for $226.
I mean if the battery exterior is mint and you do a full charge / discharge test on it, then a battery that is supposed to last 10 years in that condition is fine by me.
I actually have 4 of those...
So If I get your right, once I think my 12V battery is already charged (say by connecting two batteries in series and charging them with a 24V LifePo4 charger), THEN I would connect each individual battery on a bench power supply and leave it at 14.4 for at least 2 hours??? Can I leave them on...
Presumably the "Module level disconnect" is either the built-in MC4 connectors (which can be disconnected at the panel level) and/or a PV disconnect box outside the house before the PV wires get inside the house??? or a PV disconnect box next to the array on the roof???
I hope this little bit of sarcasm helped you feel better somehow. But I'm afraid it did not provide any value to this conversation. Perhaps you would have some valuable insight to share that would help us understand the folly of our tentative plans and save us from some unforeseen catastrophe?
Honestly, I don't know if a DIY *CAN* be compliant in certain states. I live in CA and it's the land of government oversight :-(. They don't make it easy or clear WHAT the requirements are. Even the permitting requires a solar contractor to do the actual job (or at least to sing on it)...
I have a new MPP LV2424 and a pair of LiTime 12V 100AH batteries that I bought in their "Like New" section (for $203).
Setting up my MPP with 4 solar panels and my two batteries in series for the prescribed 24V battery bank.
All was working OK but my 2 batteries were barely enough to last...
Yes. I have each string fused (15Amp), going into a "Y" connector so only 2 strings go along a 10AWG solar cable... so 3 sets of solar cables come into an aggregator box and comes out in 8AWG cable. It's all well and meeting the correct power rating / AWG.
Actually you would not loose power.
In 2S2P and you loose a battery, you loose a whole string.... so I Would end up with 24V 100AH.
In 2P2S, if you loose a battery, it means that one of. your two batteries unit is now is only 100Ah ..... Unless my understanding is not correct and the faulty...
And after *6* weeks, I finally heard back from EG4 directly. Essentially what they say "don't overpanel your system".
However, if you read the specs for their inverters, they give you a Max Utilized PV input power AND a Max Recommended PV input Power.
For instance, for the 6000xp:
Max...