Set Up Guidance

zcole · February 2017

Hi everyone! Looking for a little help and knowledge from the solar-wiz peeps as I begin the journey into solar. I have a basic set up sketched out. Looking for some guidance on it regarding if there are any changes that should be made. Products are listed and links provided if needed. Any suggestions are welcome.

Thanks in advance from this solar newbie!

Set Up Diagram: http://imgur.com/ohTVOdf

Products

MPPT Tracer Charge Controller https://www.amazon.com/gp/product/B008KWPH12/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

Go Power! 4 Stage Battery Charger https://www.amazon.com/Go-Power-GPC-45-MAX-4-Stage-Converter/dp/B007GN4VKY

1200 Watt Pure Sine Inverter https://www.amazon.com/Power-PWRIX120012S-Inverter-Transfer-Switch/dp/B00TI1D5JK

Eco Solar Cool Refrigerator https://www.ecosolarcool.com/collections/upright-refrigerators/products/solar-refrigerator-12-5-cuft-escr355ge

Trojan T105-RE Batteries http://www.trojanbattery.com/product/t-105-re/

Solar Panels (Monocrystalline) http://www.ecodirect.com/Canadian-Solar-CS6K-295MS-T4-295-Watt-Mono-PERC-p/canadian-solar-cs6k-295ms-t4.htm

zcole · February 2017

mike95490 · February 2017

Inverter too large, you list no loads needing that much power. 300W (600w surge) sure sine would handle it, with much less standby loss

Wrong charger, you want a dead simple charger solely for BULK charging, maybe a little absorb, Let the solar finish, not the genset,

4 parallel batteries (are those 200ah 12V batteries ?)

600w of solar, and a fridge, you are in 24v battery bank territory, Most DC fridges have 12/24V wiring, You list no other loads needing 12VDC,

MPPT controllers are rated by output, you need 46A output @ 12V (only 25A at 24V)

You left out any circuit protection, it's still needed for only 12V.

Suggestions:
24V system
series the 2 panels and MPPT to 24V battery bank 25A
Since you only have 25A charging capacity, you are limited to 250ah @ 24V to maintain healthy battery charge rate

Battery bank, suggest 4, 6V 200ah golf cart batteries wired in series for 24V

PV derate Assume only 80% of nameplate power for well aimed panels. your 600w just went to 480W 4 hours harvest and you collect only 1.9Kwh a day, maybe 2Kwh adding some am & pm sun Taht 1.9KWh sets your loads, unless you burn generator fuel to make up the difference

The golf cart batteries are good learning batteries, cheap and sturdy.

mcgivor · February 2017

@mike95490 recommendations are spot on, especially going 24V, you won't regret it, only thing I would suggest is a larger charge controller with a good brand name, for future expansion, we all expand, the one you listed is also too small for 12V, 295W*2*0.8÷12V=39A, double the recommended input, perhaps more if it's really cold.

On such a small system the advantages of MPPT over PWM are negligible, PWM would require 72 cell panels however , as apposed to the 60 cell ones you supplied the link for. For almost the same price a more professional 60A PWM controller with a reputable name, Schneider or Morningstar for example, which can perform equalization, needed with flooded batteries, could be had, check the host's store above. Not trying to change your mind just offering alternatives. One other thing, the difference between mono and poly panels today are almost negligible, in terms of peformamce.

littleharbor2 · February 2017

All the above recommendations and...
You show the refer hooked up to the load output of the charge controller. This is only for small loads such as lighting. The load output can be set up to operate lighting for a preset amount of time and is triggered by darkness detected by your solar array. Your refer needs to be connected directly to your battery bank

zcole · February 2017

This is all great guys, thank you! @mike95490 , @mcgivor , @littleharbor2 . Looks like some adjustments need to be made.

A couple of quick notes.

Definitely need a larger charge controller.

Yes the trojan batteries listed are 6 v 225ah I believe. http://www.trojanbattery.com/pdf/datasheets/T105RE_TrojanRE_Data_Sheets.pdf

The solar fridge. Its a new model designed specifically for solar, requires only .55kW/ day supposedly on either 12 or 24V. Crazy. Hence why is hooked directly to the controller as the instructions suggest. See here for specs: https://www.ecosolarcool.com/collections/upright-refrigerators/products/solar-refrigerator-12-5-cuft-escr355ge

That being said, does that change any of the feedback regarding the type of batteries and how they are connected together? Parallel vs. Series. Or going 24v vs 12v?

Again, thanks for all this great feedback! It's very appreciated!

littleharbor2 · February 2017

I don't see anywhere in the link that says to connect the fridge to the controller. It appears to be saying this is the minimum system required. I seriously doubt they want it connected to the load output. Do you have a user manual stating this? Most mid to higher end controllers don't even have these load output terminals.
It does look like a very nice fridge.

zcole · February 2017

@littleharbor2 I'm waiting for the shipment of the fridge so I don't have the hard manual yet, but I was thinking that set up was the case based off of this graphic I saw on the company products. But maybe it doesn't apply to the fridge model. I just thought it would be fine since the fridge is saying it only pulls .55kW/ day for the entire day, that the Tracer MPPT charge controller could handle that on the load output terminals.

zcole · February 2017

littleharbor2 · February 2017

If the peak amperage draw is within the limits of the charge controller I guess that would be fine. Make sure you have it set up for 24 hour operation. One feature of load control on these controllers is low voltage disconnect which will keep your batteries from being over discharged. This needs to be set manually if the default isn't acceptable for your particular batteries. If you are in fact using the Tracer 2210 controller you may need the optional meter to program these values. I have a 3215 model set up for a little off grid project and do have the meter.

westbranch · February 2017

I recommend that you look into how many additional PV panels you can buy for the price difference between that fridge and the cost of an ''off the shelf'', lowest power consumption, Name brand fridge , with the same features and probably a lot more internal space... the idea of a specialized high efficiency DC fridge cam from the days when PV was $20 per watt and not the sub$1 per watt of today. The new fridge efficiencies today , is sub 1KWh and getting lower each year due to Gov. Regulations... Our now 2 yr old 18 cu ft GE fridge was rated at .874KWh per day. Runs off a 1500W inverter, and could probably run on a 1000W inverter but then there would be little power for the vacuum...
good hunting, there are some references to 2017 ratings but not many yet https://www.energystar.gov/productfinder/most-efficient/me-certified-refrigerators

zcole · February 2017

It also sounds like I definitely need to get a larger charge controller. Would the 40 amp Tracer MPPT model be able to handle 2 or maybe 3 of the 295 watt each solar panels?

Controller: https://www.amazon.com/dp/B00E7NI9PE/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=4R4NG9XB4X6A&coliid=I39CX9YYHKWHBO&psc=1

Solar Panel: http://www.ecodirect.com/mobile/Product.aspx?ProductCode=Canadian-Solar-CS6K-295MS-T4

Panel info:

Watts (STC)	295 W
Max Power Voltage (VMPP)	32.3 V
Max Power Current (IMPP)	9.14 A
Open Circuit Voltage (VOC)	39.5 V
Short Circuit Current (ISC)	9.75 A
Max System Voltage (UL)	DC 1000 V

littleharbor2 · February 2017

This controller has a 100 Voc limit. You will only be able to series wire 2 of those panels . You will also need to go with a 24 volt system as the Mfg. states 400 watt max @12 volts, 800 Watts @24 volts.

westbranch · February 2017

Those panels are OK as long as you have an MPPT controller, regardless of 24 or 12 v battery. BUT if you want to use 2 panels you need to go to a 24V system. that Controller will not handle 3 panels in parallel for 12v (amps too hi) or series for 24V system (watts too high).
the MPPT will ensure you can use all the power those panels produce.
You must have at least 2 in series to charge a 24v battery properly, 36V Vmp is not enough to do the Absorb or Equalize phases... It is not good to run electronic devices at their max. , they fail much faster when over ~ 80% of design specs... Suggest looking for a better CC..

All cheaper controllers have a gotcha...just looking at page 22 of the manual,
http://www.renogy.com/template/files/Manuals/20A-30A-40A-MPPT-Solar-Charge-Controller-Manual.pdf
it shows that the unit will disconnect at 16/32V in 12/24v systems.
You will have to confirm the charging specs for the batteries to make sure they do not have a high Absorb or EQ voltage, above the 16/32V limit...
hth

zcole · February 2017

Thanks @westbranch Will definitely be switching everything over to a 24V system. You have any good recommendations for another MPPT controller that would be better?

The batteries I'm considering are four of the 6V Trojan T105re model wired in series to get the 24V setup.

Battery Specs: http://www.trojanbattery.com/pdf/datasheets/T105RE_TrojanRE_Data_Sheets.pdf

littleharbor2 · February 2017

Also, from Page 15 of the owners manual.

NOTE: The load terminal is commonly used for small lights or other low amp drawing devices. The terminal is powered by the battery bank connected to the charge controller. The load will NEVER draw power directly from the solar panels.

You know there is a 30 amp 150 volt version of this controller. You could go with 3 lower powered 60 cell panels in series if you were set on using 3 panels.

zcole · February 2017

@littleharbor2 That is an option... not concerned about the number of panels, doesn't have to be a certain amout. I'm more concerned about the correct panels paired with a charge controller that can handle them, feeding those Trojan t105s.

littleharbor2 · February 2017

Understood. My point being, with a higher Voc capable controller you could use 3 panels in series. The only way to use 3 panels in parallel would be with a 12 volt setup because of lower than 24 volt nominal voltage per panel but then you need a higher amp controller. Another option would be to two of the larger 72 cell (24 volt nominal) panels.

westbranch · February 2017

Well we sort of started off somewhat in the middle...

Let's start with what it is you want to power with those batteries? These will be all the loads needing power..

Also, 225A at C20hr rate so we need ~ 22A from the charger at 24V for a 10% charge rate.

Where are you going to use this system? Location s important to how much sun and other loads there are or are going to be eventually

BB. · February 2017

Note, 72 cell panels are 36 volts Vmp.

-Bill

zcole · February 2017

@westbranch :: We're looking to power just a few necessities as follows...

These would be the max pull at one time (which would rarely happen as all of them would not be used at once) This is for a small setup for a little cabin. West coast. Completely off grid, with a generator as a backup. Sun averages 4 hours as a low and higher.

Overall the fridge is priority.

- Eco Solar Fridge (0.55 kWh / day)
- Info: https://www.ecosolarcool.com/collections/upright-refrigerators/products/solar-refrigerator-12-5-cuft-escr355ge

- 6 LED 10 Watt Bulbs (60 watts)

- Bathroom Fan (60 watts)

- iPhone Charger (5 watts)

- iPad Charger (12 watts)

- Bluetooth Charger (12 watts)

- Toothbrush Charger (1 watt)

westbranch · February 2017

Do you have a spot chosen for the Array?
Have you sat around for a whole day in the winter and watched shadows that cross where the array will go?
How far is it to where the CC, batteries and inverter will be? (in the cabin?)
How far from the batteries to the fridge?

estimates of daily uses you listed...

Please review

Fridge                                                                 = 600 Whrs
Lights 60w x 5 avg hrs (more winter, less summer) = 300Whr
fan 60w x 2 hrs = 120whr
charger 5w x 5 hrs                                             = 25whr
charger 12 w x 5 hrs          = 60w hr
BT charger 12w x 6 hr    = 60 whr
Tbrush 1w x 24 hr                                              = 24 whr

TOTAL 1189Whr or rounded up to 1.2Kwhr

now you can deduct say up to 4 hrs of use for some of these as they will get powered by the sun
so at say 1.0Kwhrs you need 1,000Whr / 4hrs FULL sun = 250w just to replace use , so 2 - 290w panels are needed to cover your use and other losses.

mike95490 · February 2017

I would suggest you consider the Morningstar MPPT 60. It's a bit over power, but it has a very nice web interface for monitoring things.
Over time, loads grow and you will want more panels.

I will repeat the 4 golf cart battery suggestion, cheap and easy to learn with, and you don't break the bank when you kill them, Should last 2 years with the loads you list, maybe longer if you baby them, Unless you set something up wrong and kill them, The price to replace cart batteries vs the larger T105's, or learn on the cart batteries and replace them with T105s
24v x 200ah = 4,800Wh which at 50% DoD, gives you 2.4 usable KWh The T105's are only a little bit larger capacity..

mcgivor · February 2017

mike95490 said:

I would suggest you consider the Morningstar MPPT 60. It's a bit over power, but it has a very nice web interface for monitoring things.
Over time, loads grow and you will want more panels.

I will repeat the 4 golf cart battery suggestion, cheap and easy to learn with, and you don't break the bank when you kill them, Should last 2 years with the loads you list, maybe longer if you baby them, Unless you set something up wrong and kill them, The price to replace cart batteries vs the larger T105's, or learn on the cart batteries and replace them with T105s
24v x 200ah = 4,800Wh which at 50% DoD, gives you 2.4 usable KWh The T105's are only a little bit larger capacity..

The money saved on golf cart batteries could go towards a quality charge controller such as Mike mentioned, personally I'm a little skeptical about those made in China units being up to the task, especially in the higher amp ratings, some are smaller than just the heat sink of the Morningstar, where dose that heat end up....in the electronics? less reliability.

zcole · February 2017

Hi everyone! Thanks so much for the feedback so far. It seriously is amazing!

I've updated my graphic with the new information based off of the feedback I've gotten all around.

One big note that seemed to be a concern was the fridge being connected straight to the charge controller. And sure enough, after talking with a tech from the company that makes the fridge, that is how they recommend the setup... straight to the controller.

Is the wiring of the solar panels and batteries correct to achieve 24V?

What does everyone think now? What other changes need to be made as I'm sure I still am messing something up here, haha.

Thanks again! @mike95490 @mcgivor @littleharbor2 @westbranch

Image: https://us.v-cdn.net/6024911/uploads/editor/ng/vte2avw43af2.jpg

littleharbor2 · February 2017

Any 295 watt Monocrystalline solar panel will be Minimum 60 cell but more likely 72 cell, 24 volt nominal. You still will need to series wire them to get your voltage high enough for the MPPT controller to do it's thing.

mike95490 · February 2017

One big note that seemed to be a concern was the fridge being connected straight to the charge controller. And sure enough, after talking with a tech from the company that makes the fridge, that is how they recommend the setup... straight to the controller.

Well, I'm out of luck. My 3 controllers have no load output.

Cheap controllers have load terminals, makes users think they are getting something, Large professional controllers don't have load control

Baloney ! You have to get the accurate starting surge of the fridge, and make sure it is within the Load limit of the controller. Nothing more fun than waking up to find your charge controller blown from too large of a load.

Corrections to the new drawing:
40A fuse at panels, not needed. Better to have a 15A PV breaker in a box next to the output breaker for the controller battery cable.

Every wire with a 40A fuse or breaker, must be 8ga or heavier, The fuse is to protect the wire.

mcgivor · February 2017

mike95490 said:

One big note that seemed to be a concern was the fridge being connected straight to the charge controller. And sure enough, after talking with a tech from the company that makes the fridge, that is how they recommend the setup... straight to the controller.
Well, I'm out of luck. My 3 controllers have no load output.

Cheap controllers have load terminals, makes users think they are getting something, Large professional controllers don't have load control

Baloney ! You have to get the accurate starting surge of the fridge, and make sure it is within the Load limit of the controller. Nothing more fun than waking up to find your charge controller blown from too large of a load.

Corrections to the new drawing:
40A fuse at panels, not needed. Better to have a 15A PV breaker in a box next to the output breaker for the controller battery cable.

Every wire with a 40A fuse or breaker, must be 8ga or heavier, The fuse is to protect the wire.

Some more professional charge controllers Morningstar for example, can be used as a diversion controller, load controller or charge controller, but only one.To achieve more than one function, a relay driver can be used, see attached pdf. personally I would choose a more professional controller to take care of my equipment, and not use the load contacts of a cheaper unit to run a refrigerator, don't want to go broke saving money, but each to their own.

petertearai · February 2017

again consider a inverter fridge , run off your inverter . simpler and probably cheaper .

Set Up Guidance

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