Classic 150 and Rolls S6 L16-HC settings

[MountianComm]

I am getting ready to install an entire solar plant at an off grid communication site.  The site will be remotely monitored however be for I can configure that I must have power.
I have a Classic 150 and a 48 volt battery plant (8 new Rolls S6 L16-HC) with the big water miser caps, only one string of batteries for now.  Plan is to add a second later in the fall.  Solar array are used Sharp 167W panels.  They are down about 10% from new ratings, 18 panels configured in 6 strings of three panels somewhere around 70 VDC at 6.5 amps.

The building is a 12X12 two story filled Concrete Block building.  Batteries and charger are in lower level.  Batteries are housed in a Plywood insulated box.  The site is on top of a mountain at 7200 feet in the North eastern sierra's.  Temps (outside) vary from 80's in the summer to -30 degrees in the winter.  I am not sure yet how cold the building gets inside.  Taking all sorts of measures now to stave off the cold but concrete block buildings do cold soak. 

Panels are orientated due south and fixed at 60 degrees tilt.  Site gets good early morning sun, however shading becomes and issue after 2-3 pm.

I have the wizbang current sensor for the classic too.  Current draw by site equipment is pretty minimal 1-2 amps at 48VDC.

What would you recommend the charge setting be on the classic?

I am new to off grid communications, all other site I use have commercial power and generators (power surges kill equipment at these sites)

[mike90045]

You will need the battery temp sensor installed and set for your batteries, when that cold, the voltage will crank up a bit above normal charging voltage, make sure your inverter can survive that voltage, could be over 65V

To reduce gassing (water consumption) I'd keep absorb voltage a hair lower, and for longer time.

Your panels, if they accumulate snow, will not charge the batteries, maybe for weeks.

You will not "guess" it right.  It's going to take hands on & monitoring to get it dialed in.   Will you be able to run the Local App from your base station ?  You can dial in the settings from it.

I've found that the pre-dawn voltage reading of the bank is the best indicator of how well it was charged the previous day.

[Vic]

Hi again Jim,

Would guess that strings of three of those Sharp PVs  will probably not have quite high enough string Vmp,  to be able charge/EQ  those Surrette Flooded batteries.

You probably have the Surrette Battery Manual,   but it is here:
https://www.solar-electric.com/lib/wind-sun/surrette-manual.pdf

MidNite has a great String Sizer for the Classic:
http://midnitesolar.com/sizingTool/index.php

Think that this data sheet may be for the candidate PVs:
https://www.abcsolar.com/pdf/sol_dow_167W_SS.pdf

It can create a bit of a problem,   when Lead Acid batteries are added into  battery bank,  that are not the same age as the originals.   The greater the age difference,  the greater the potential problem in how well the batteries play together.

More later,  73,    Vic

[Vic]

AND,  in the interim,  ran arrays of 18, six of three,  and of 20  --  five of four,  using a datasheet for Sharp 167s,  that was on the Web (may not be your PVs,  but prob are).

Attached are the results.   Five strings of four 167 looks fine for your environment,   and meets the advice of having the string voltage be no less than 130% of the highest battery voltage ever needed   ...   You may not have 20 PVs,  and the 167s were found,  are an unusual cell configuration  --  48 cells.   So,  if you do not have some spares,  or a source,  finding more might be a bit iffy.

Of course,  if you can spare the power,  four strings of four 167 would be fine.
And,  IMO  with a 48 V Flooded Lead Acid (FLA)  battery,   around 90 V STC string voltage,  is about the perfect operating point for a Classic 150.
Edited: Typo correction, & clarity.
FWIW.   73   GL   Vic

[MountianComm]

Some follow up...
I took two 18 hours days but the whole system was installed.  and so far things are working well ( on the power side)  The array is 18 panels in 6 strings of 3 panels as I described.  The panels are the sharp NU167U3.  I would have liked to done 20 panels, but I only had 19 and the rack size for the building would only fit 18. 

Not much draw on the batteries maybe 2 amps???  So far everything on the site is DC power.  I have to use DC-DC converters all the radios are 12VDC.  Horrible inefficiency using the DC-DC converters!  80% at best!! also the Wilmore DC-DC converters I use have a max input of 58VDC.

I still have some learning to do with the settings.  max absorb voltage set to 57.5 volts. 

I had my resident solar guru (bill from FRSE) onsite to set up the CC. 

I don't have the remote microwave setup yet. so I cant monitor the CC yet.  I am hoping to have that done before winter.

Batteries had been wired in series/parallel for 12VDC to run small inverters to charge tool batteries, so they were drawn down a little.  however in less than an hours they were all topped off and the CC showed only 20-30 watts of power going into the batteries.

I haven't been back to the site yet, it has been a week.  the one APRS digipeater has been up and running without issue. 

I am wondering is their an interface for the whizbang and a shunt that I can use to meter the loads?  this would be a separate shunt that is inline to measure how much power the communications equipment is using?

TNX Jim 

 

[ClassicCrazy]

I had an Argent Data digipeater and it had some telemetry inputs . You could set up Aprs.fi webpage to display the telemetry so that is one option to monitor some things.
I had the OTM2 but they are already making some newer generation units and I haven't kept up with all the features. One nice thing about the one I had was you could remote into via messaging over the internet to program it and it also had a built in mosfet to turn some loads on or off too.  The Argent products always seem to have a few bugs in them that take awhile to get sorted out or not sorted out - at least from my experience. But it did work pretty good - I had digipeater with weather station input to one little box .

Larry

[mcsarge]

I am wondering is their an interface for the whizbang and a shunt that I can use to meter the loads?  this would be a separate shunt that is inline to measure how much power the communications equipment is using?

You can interface to the Classic 150 using the IP based MODBUS port (or the USB one) and ask it what the load is on the shunt. There is an entire project that I have participated in that you can setup to poll your Classic and publish the data. In your case, maybe you want that data to be available to the digipeater so when you type a code in it will speak the current  - positive for charging, negative for consuming.

Here is the main site for the project, but it is mentioned here in the DIY forums. https://github.com/ClassicDIY

- Matt

[Vic]

Commission the Surrette bank,  per  the Battery manual,   linked previously.   Do this soon,  if you have not done so.   Details of  Commissioning are in the Surrette Battery Manual,  linked above.

Use these charge settings,  and recommendations,  when you get into regular cycling:
http://support.rollsbattery.com/support/solutions/articles/237882-calculating-proper-charge-settings-for-rolls-flooded-lead-acid-batteries

Get a very good Hydrometer to measure SGs,  and log  these into the Battery Logbook. Number  each  battery,  and  letter  each cell, mark them with a Sharpie  pen.

Use  ONLY Distilled Water to  make  up  for electrolyte loss.

The PVs  that  are in  the  Link above,   are Sharp ND 167U3A,    is that the  model  number  of  PVs  that  you are  actually using?

ATTTENTION,   ATTENTION !   ATTENTION   !!!

The following is the recommendation from  MidNite Solar (taken from the Classic String Sizing  Tool output after the system  and environmental data is Submitted:

"NOTE: Generally speaking you'll want to use the Classic 150 or 200 as they are less expensive and will handle more power. With MPPT controllers the higher the input voltage the less efficient they are. This is not a large value but it will add up to a little more heat in the controller and a point or two less in efficiency. BUT you also have to be careful not to have the input voltage to low. Most all MPPT controllers will want to see a minimum of 130% of the actual high battery voltage. So if we have a 48v battery and it has an Equalize voltage if 62.3 volts than we would multiply that by 130% and we would need a minimum of 81 volts on the input on the hottest day of the year in order to have enough headroom for the MPPT to work".

As stated  previously,  your strings of  three PVs with Vmp of 22.8V,    has a too-low  Vmp to reliably charge and EQ  Flooded batteries in a 48 V system.  Unless,   you are using different Sharp 167 PVs.

FWIW.