Small Cabin

Small Cabin Forum
 - Forums - Register/Sign Up - Reply - Search - Statistics -

Small Cabin Forum / Off-Grid Living / Solar Equipment is Alive... kind of!
Author Message
Nobadays
Member
# Posted: 20 Jun 2019 18:47 - Edited by: Nobadays
Reply 


The cabin solar power system is coming to life! It's been a journey from really trying to figure out what are power consumption is and what it might be then trying to size a system to handle our usage. I think way back there I was one of those people asking how many batteries and how many panels do I need.... before I had even done an energy audit. Heck i didn't know what that was or where to begin. Truth be told I'm still not the guy to go to for answers! I only know enough to get in trouble!

Here is what we have. 1470 watts of panels, 4 x 2kw lithium Chevy Volt modules 48v - so 8kw storage (about 160 amp hrs but with lithium compared to FLA would equate to maybe around 300amp hrs - somebody can correct me here!) Schneider SW4048 charger/Inverter and Schneider 60/150 charge controller. I'm using a Square D QO 100 amp load center with a 35 amp breaker for each module.

As of today we used the generator to bring all the modules up to 48.8v, let it go into absorption for 6 minutes then shut down the generator. All afternoon on the battery pack, pretty sweet! Tomorrow my son in law arrives to help us get the panels mounted on the roof and "Bob's you're uncle!" We will be using sun power instead of gasoline!

BTW, any of you thinking about putting a system together I would strongly suggest buying the pre-wired equipment from your manufacturer of choice...l I don't believe we saved a dime after running all the conduit and wire to connect all the pieces. Not yo mention the hours of labor that went into doing all that work.

Cheers!

Edit... not pre-owned equipment but rather "pre-wired" equipment!!!
Solar equipment
Solar equipment


creeky
Member
# Posted: 21 Jun 2019 09:21
Reply 


Quoting: Nobadays
Not yo mention the hours of labor


Ain't that the truth. That's why I tell folks. Take your time. The labour can double the cost.

Nice looking system. How did you get the SW to stick to 48.8 absorb off the charger? We kept finding it wanted to switch to a 58.6v. Bad news.

Keep an eye on that (of course, once you're on solar you're golden)

Steve_S
Member
# Posted: 21 Jun 2019 09:56
Reply 


Looking Good, I can tell your excited ! Wait till you see the Charge Controller reporting #### Watts, ### Volts and seeing the word "FLOAT" on your controller, THEN get excited !

I second that on PRE-WIRED... sure it costs more up front but when you DIY it, all the $20 here, $30 there, $50 for that & $10 for this … it adds up FAST and you end up spending the same, if not more (time not added but that's $$ too).

I have a Midnite Classic 200 and bought the extras, would have actually been better off just buying one of the "E-Panels" with controller, DC Stuff and everything ready to go and you can pick from a choice of Inverter Chargers pre-mounted or an E-Panel which you can put your own Inverter/Charger on.

Nobadays
Member
# Posted: 21 Jun 2019 10:10
Reply 


Creeky.... luck? Not sure what I have done differently. I spent some time on the phone with my solar engineer at NAZWS and he helped me get the numbers in there.

Maybe one thing that we found will help.... custom battery settings would not let us get the numbers as low as we wanted so he suggested setting it on Lithium batteries and then doing advanced settings for that. This worked and they have held.

Here are my settings... let me know if you see something out of place! To be honest I'm not all that clear about what these numbers mean, esp "bulk term voltage". I just found that in order to get the bulk voltage to match my absorb volts I had to have the bulk term voltage .8 points lower than the bulk voltage.

Battery type - Lithium
Max charge rate - 100%
Bulk voltage - 48.6
Bulk current - 45.0A
Bulk term voltage - 47.8
Absorb - 48.6
Max absorb current - 45.0A
Float - 48.0
Max float current - 45.0A
Absorb time - 6 minutes
Temp comp - 0
Equalization - disabled

Are there other settings I should look at/change?

We ran the generator yesterday evening again just to bring the modules up full before bed.... well we shut the genny off at 7pm but when we went to bed at 9:30 the level was still at 48.6v. When we got up a 6am the level was 48.1v. The only thing running at night is our 3.5cuft freezer.

Pretty sweet this morning not to have to traipse outside to start the generator before grinding coffee!

Would love to hear your thoughts on these settings. I will keep you informed if I see my settings jump. Will put the Redwing BMS on today. I have a crappy volt meter but after checking the cells before I fired everything up I saw there were a couple of unbalanced cells in two of the packs... off about .1 volt...maybe if I can believe my meter. Got to get a better meter!

Nobadays
Member
# Posted: 21 Jun 2019 12:41
Reply 


Steve.... I spent over a week putting all of that conduit in and running wire. Part of the time was "running to town- an hour one way with 45 minutes of that on rough rock roads - just to get a tee or terminal end I was short of. Of course bought way more fittings than I needed because I didn't want to run to town but always missing THE fitting or lug or short on wire something I hadn't foreseen. Yeah... buy the pre-wired!

Pretty jazzed though and my kids are on their way to help get the panels up. We have to roof mount because of our location, lots of Aspens, and it's a 12/12 metal roof.... not a place for a one armed man to be working...heck I would just be holding on! They are bringing ropes and harnesses and are used to high angle work... I'll pass tools up!

Steve_S
Member
# Posted: 21 Jun 2019 13:07
Reply 


Ohh the running to the store part I know Ohhh Soooo Welll…. Considering that in my case, that included 200km trips on occasion to get something not available nearby. Yup, did the Buy Extras to make sure I had what I needed too and still had to get part A or attached B somewhere.... RV, Boating & Auto supply places got to know me too ! LOL.... WHAT A PAIN !

I didn't put my panels on my roof 9/12 pitch as it's reasonably shaded. I built a "rack" @ 45 deg. on the side of my 20' Sea Can and that was a good move as I can clear snow if needed and rinse the panels during pollen season (man they turn yellow fast ! = lots of sneezing too ).

This morning something "cool" happened. A couple of local Lumber / Logging mills have gone solar or hybrid around here in past couple of years. This morning I ran into my Cedar Supplier who runs a mid sized mill operation & a small hobby farm, he asked me to go out and discuss with him how he can switch to Solar Power to run his mill equipment and further to run his farm op as well. He's tired of the diesel costs and how it's hurting his profit potential, so he's looking at the others around and realized that there is a better way. This could get FUN and a decent side project for me to help him out.

Nobadays
Member
# Posted: 21 Jun 2019 13:28
Reply 


Steve.... PITA for sure to live far out but.... also love it! We are summer dwellers here at the cabin, winter visits but not full time. With a 45* angle on the roof snow doesn't stay long on it anyway!

I wouldn't be confident enough to "side job" with solar stuff yet. I bet over the course of time I will become intimate with how all this operates. I do have a neighbor who has already been over to look at what we have so far. He has done some solar stuff for a construction company he worked for. I guess, like your mill owner, the construction company found solar to be cheaper in the long run for their maintenance trailers and portable office, etc. To big of power demands for the rock crusher.

creeky
Member
# Posted: 22 Jun 2019 08:43
Reply 


Hey thanks for the settings. I did the same thing for a customer and his settings disappeared. I always wondered if it he had been fiddling after I left. Guess so!

I build all my SWs with the combiner box. And I've used the epanel from Midnight solar. Man it was great. Really sped up the job.

Btw: for all volt module users. I've reduced the max voltage to 48. The data is showing longer life with 70% middle of the pack use as opposed to 80%. (From 30 years to .... who knows). Some of us have actually gone to 47.5 during the summer. Then back to 48.3 for the fall and that bit extra.

Nobadays
Member
# Posted: 23 Jun 2019 08:46
Reply 


Creeky.... one thing I noticed.... the first time I set up the charger was to see if all the magic smoke stayed in the wires but I still had a bit more wiring to do on the AC side so I shut down the battery feed to the charger to kill all potential power. When I kicked it back on the settings on the charger/inverter had rolled back to defaults. The charge controller maintained its custom settings. YMMV

I haven't turned the units off since I fired up the second time so don't know if that is common or if I had left the SCP in advanced settings and maybe that triggered the roll back.

Keep'in my eye on it!

Cheers

creeky
Member
# Posted: 23 Jun 2019 09:19
Reply 


Ya. Return to default. I hate that. I'm putting my setting on my boards now. So if there's a fubar they can be reset by the owner.

Perhaps the saving grace is how often do you use the charger? I use mine about once every, um, gee its been years.

Nobadays
Member
# Posted: 23 Jun 2019 09:48
Reply 


I'm going to do more research, manual scouring, maybe contact Schneider to see if there is a way to "lock in" custom settings. It stands to reason if you were to do a Firmware update everything would revert but just turning the unit off shouldn't I think.

We should get the solar hooked up today with any luck. We were making good progress yesterday with the rails up, the Rapid Shutdown units mounted and ready to start bolting panels down. Then it started sprinkling, raining then thunder and lightning ... off the roof. Have all of the wire from roof to controller yet to pull and some conduit left to install to bring the PV lines down off the roof. As long as the weather will hold though I think we will get it done.

Going on 48 hours now since the modules were last charged 48.6v) right now still at 45.6v. Probably will fire up the generator later today if we don't get the solar producing early enough today.

Cheers!

Brettny
Member
# Posted: 23 Jun 2019 12:41
Reply 


Are you useing a BMS on the chevy volt batterys? How are they all connected?

Il be useing either chevy volt or nissan leaf batterys on my system.

Nobadays
Member
# Posted: 24 Jun 2019 09:28
Reply 


Brettny.... I will be using one of Creeky's Redwing BMS units. As yet to hook it up. I'm pretty sure there are a couple of unbalanced cells in a couple of the modules but not too bad and nothing the BMS won't clear up. The modules are healthy.

I'm running all of my negative side to a busbar (#2 ga) then off the busbar with 4/0 to the inverter/charger. The #2 ga cable on the positive side come up into a Square D 100amp QO load center. The QO breakers are ac/DC to a point - though they are rated at 48vdc, I'm told they will take 60vdc all day and can spike higher.... which shouldn't happen anyone way. My peak charger output is around 50vdc. Square D 35amp QO single pole breakers will handle up to #2 cable.

That's kind of how the modules are hooked up... hope that helps. I'll attach the solar engineer's schematic. It might help some folks.
DonWelch_WireDiagram.pdfAttached file: DonWelch_WireDiagram.pdf
 


Nobadays
Member
# Posted: 24 Jun 2019 09:57
Reply 


BTW.... the RSD (Rapid Shutdown) Initiator wiring is not correct in the diagram. It shows it's power being drawn from L1 and L2, in fact it should only be from L1 or L2 plus a common. The 24vdc transformer for the rooftop RSD units is powered by 120v.

Wilbour
Member
# Posted: 24 Jun 2019 11:26 - Edited by: Wilbour
Reply 


Nobadays

Interesting. When I wired up my system I put the battery disconnect between the bus bar and the inverter like yours. Then reread my schematics and saw the original drawing had it between the bus bar and the charge controller. I have since relocated it as such and added a 4 way switch directly on the batteries (1. All off, 2. All on, 3. Battery A on, 4. Battery B on)

Not sure if it matters where the disconnect is.

Brettny
Member
# Posted: 25 Jun 2019 12:21
Reply 


Creeky makes his/her own BMS? Where do i find out more info on this?

Wilbour
Member
# Posted: 25 Jun 2019 12:33
Reply 


Brettny
Google: bobolink solar

Steve_S
Member
# Posted: 25 Jun 2019 13:03
Reply 


Geez Louise.

https://bobolinksolar.com/ <-Creeky's main page

https://bobolinksolar.com/product-category/lithium-battery-packs/ the lithium packs and accessories to make it work.

Brettny
Member
# Posted: 25 Jun 2019 16:09
Reply 


Thank you

Scott G
Member
# Posted: 27 Jun 2019 19:56
Reply 


Epanel. Have to look into that. Thanks.

Wilbour
Member
# Posted: 27 Jun 2019 21:20
Reply 


Brettny

Wasn't trying to be a jerk, I just don't want to see a good contributor lose his posting rights by having his own company promoted too heavily here.

Creeky has good information and has a business as well. I've been on forums where a poster gets booted for using the forum as a free advertising service.

But now that it's been mentioned, follow the link provided above. If you want to see my 24v setup in person I'm just a ferry ride from Cape Vincent NY.

Steve_S
Member
# Posted: 28 Jun 2019 08:29
Reply 


I posted Creeky's links because I'm not creeky and figured I wouldn't get into trouble for it, as I am just another Forum Member with no vested interests in any company. My ONLY vested interest is to get people using Clean Renewable Energy as best as they can for their (and ours) benefit.

He has some great products and good prices for his stuff and I'm all for encouraging folks to go RE and he's helping doing that. I don't see Cabin Builder (owner of the site) have an issue with that. No Spamming going on here.

RE E-Panels, here's a great explanation:
MidNite Solar E-Panels Explained (PDF)
http://www.midnitesolar.com/pdfs/E-Panels_Explained.pdf

creeky
Member
# Posted: 28 Jun 2019 09:15
Reply 


thx all. I am working very hard to promote RE. And I get thank yous from all over the world. I know. It way surprises me.

Those e-panels are great. Really makes wiring easier. But you can do the same thing yourself for less. Like everything we DIY off gridders do. You can do it the right way, six ways. Cheapest to most expensive. And the ratio of easy to hard is usually the inverse of the cost.

MondayCreek
Member
# Posted: 28 Jun 2019 12:47 - Edited by: MondayCreek
Reply 


Quoting: creeky
Btw: for all volt module users. I've reduced the max voltage to 48.


Thanks for the update Creeky! What are you recommending for the maximum (lowest) discharge voltage?

creeky
Member
# Posted: 29 Jun 2019 10:14
Reply 


I have kept it at 39.8. Pretty conservative. You could go 41 for longest life. But folks rarely get anywhere close to that number.

I got a customer year long update the other day. 45.3 was the lowest voltage. Put on more loads I said!

creeky
Member
# Posted: 3 Nov 2019 10:10
Reply 


Nobadays.

The SW has a new addendum release:

So for your inverter not storing the settings when turned off

Storing the State of the Inverter Mode
You can enable or disable a feature called StoreInvState which, when enabled
remembers the state of the inverter mode prior to a power down (that is, when AC
and DC power sources are disconnected). When the CSW is powered up again,
the inverter mode reverts back to its prior state.
See “New Advanced Features Setting” on page 12

Nobadays
Member
# Posted: 3 Nov 2019 13:59
Reply 


Creeky.... yep saw that the other day when I was writing down all the settings before shutting the system down. Wasn't sure that was exactly what that setting was for but assumed it was.

Regardless, I shut everything down la se t Saturday, my rig broke down on the way out so went back up to the cabin.... powered up the system and all settings remained the same. Even on the inverter/charger!

I will definitely make sure that setting is enabled when I go back up there.

Thank you!

rachelsdad
Member
# Posted: 3 Nov 2019 15:15 - Edited by: rachelsdad
Reply 


Quoting: Wilbour
But now that it's been mentioned, follow the link provided above. If you want to see my 24v setup in person I'm just a ferry ride from Cape Vincent NY.



Hey Wilbour,

Would you mind posting a few pix of your modules? I just got my 24 volt modules and I'm a bit concerned I am going to wire all correctly. Really nothing on web save for us knuckleheads.

Wilbour
Member
# Posted: 4 Nov 2019 13:19
Reply 


rachelsdad

http://www.small-cabin.com/forum/3_8226_1.html

There is not much of a wiring diagram here but shows you my set up. As it stands now, I have 2kw of lithium 24v. a 500w inverter. I installed a big red 2 input switch to make the assembly easier as I really hate popping out batteries and leaving the leads alive.

Check out Bobolink solar and poke around. There is a free pdf file showing you how to connect all your bits and pieces. My only different addition was to install a switch between the batteries and the busbar as I did not want the batteries connected to the inverter all the time. Also gives me the option to run a single battery if the other needs maintenance (not likely)

Your reply
Bold Style  Italic Style  Underlined Style  Thumbnail Image Link  Large Image Link  URL Link           :) ;) :-( :confused: More smilies...

» Username  » Password 
Only registered users can post here. Please enter your login/password details before posting a message, or register here first.