A Forum run by Enthusiasts of MidNite Solar

Gallery of Installation pictures => Owner Installed system pictures => Topic started by: BAndrews on December 23, 2016, 10:48:18 PM

Title: SE Atlantic
Post by: BAndrews on December 23, 2016, 10:48:18 PM
Just winding it up for this round of changes.  Feel like a new parent.   :-)



Title: Re: SE Atlantic
Post by: ClassicCrazy on December 24, 2016, 11:48:35 AM
Wow that is a neat installation.
Though I believe there may be a  better way to wire up those parallel strings of batteries to ensure they are better balanced .
http://www.smartgauge.co.uk/batt_con.html

Larry
Title: Re: SE Atlantic
Post by: ClassicCrazy on December 24, 2016, 01:34:33 PM
I am curious why are there so many Midnite surge protectors ? One for PV , one for AC  - what are all the others for ?
Title: Re: SE Atlantic
Post by: russ_drinkwater on December 24, 2016, 04:33:26 PM
Wow, sniff snuffle makes mine looks like a dogs dinner! :o :(
Nice job to whoever did it!
As long as it works and is reliable as well.
Title: Re: SE Atlantic
Post by: BAndrews on December 24, 2016, 05:49:47 PM
Quote from: ClassicCrazy on December 24, 2016, 11:48:35 AM
Wow that is a neat installation.
Though I believe there may be a  better way to wire up those parallel strings of batteries to ensure they are better balanced .
http://www.smartgauge.co.uk/batt_con.html

Larry


My series strings run more-or-less horizontal.  My parallel strings run more-or-less vertical.  I think my parallel junctions match theirs ..... I think....... 

I'm pulling load from the lower left (+) and from the upper right (-).  Am I missing something here?  I sure very much appreciate any pointers.



Quote from: ClassicCrazy on December 24, 2016, 11:48:35 AM
I am curious why are there so many Midnite surge protectors ? One for PV , one for AC  - what are all the others for ?


The Four Star Power Center came with 3 SPD's installed.  I believe the top SPD protects the inverter or controller.   The middle SPD protects the generator AC input (no gen currently installed).  The lower SPD protected the PV input.  When I relocated the PV input, I moved the lower SPD to the battery pack input.  I don't know if this is effective or efficient.  Thoughts?  Also included in the Four Star package was the lower combiner box.  It also came with an SPD so it looks like one of these PV input SPD's was redundant.

Currently, the lower combiner handles the PV input of tower 1 and tower 2 (T1 & T2).  The  top combiner handles the PV input from tower 3 (T3) with expansion room for 4 more 345 watt panels.



Title: Re: SE Atlantic
Post by: BAndrews on December 24, 2016, 05:56:21 PM
Quote from: russ_drinkwater on December 24, 2016, 04:33:26 PM
Wow, sniff snuffle makes mine looks like a dogs dinner! :o :(
Nice job to whoever did it!
As long as it works and is reliable as well.


Double checking all connections prior to initial fire-up revealed that a few connections had loosened up.  After taking care of those, the system booted right up.  The Classics are set up in follow-me mode and programming in both is set to Rolls specs.  We have a lot of crap in the air column here from geoengineering aerosols, so typical output on a sunny day is 2600-2800 watts.  I have seen it hit 3200 watts once tho.

No trouble in several weeks of operation.  This stuff is addicting.   :-)




Title: Re: SE Atlantic
Post by: ClassicCrazy on December 24, 2016, 07:19:02 PM
Are you using ending amps to terminate your absorb or going by time ?  Of course you need a Whizbang to use the ending amps approach.


Larry
Title: Re: SE Atlantic
Post by: BAndrews on December 24, 2016, 09:40:32 PM
Quote from: ClassicCrazy on December 24, 2016, 07:19:02 PM
Are you using ending amps to terminate your absorb or going by time ?  Of course you need a Whizbang to use the ending amps approach.

Larry


Ending amps.

I don't have the docs with me now, but as I recall there were a few simple calculations.  The formula is in the the product docs. 

Ya'know, in fact, I did need some clarification on the values obtained.  I have not updated this value yet.  Seems I recall that the Rolls docs called for a ending amps at a very high level.  I gotta talk to Midnite tech support and get clarification ....











Title: Re: SE Atlantic
Post by: ClassicCrazy on December 24, 2016, 09:54:58 PM
Quote from: BAndrews on December 24, 2016, 09:40:32 PM
Quote from: ClassicCrazy on December 24, 2016, 07:19:02 PM
Are you using ending amps to terminate your absorb or going by time ?  Of course you need a Whizbang to use the ending amps approach.

Larry


Ending amps.

I don't have the docs with me now, but as I recall there were a few simple calculations.  The formula is in the the product docs. 

Ya'know, in fact, I did need some clarification on the values obtained.  I have not updated this value yet.  Seems I recall that the Rolls docs called for a ending amps at a very high level.  I gotta talk to Midnite tech support and get clarification ....

You can start out with what you have for ending amps. The way I do it is to watch the SOC on Mymidnite along with the system amps . As the SOC counts up towards 100% then the system amps should start to level off. I also take a few specific gravity readings from the batteries to confirm that when it gets to 100  % SOC that the SG reading is what is recommended by the battery manufacturer.   You also need to set the battery efficiency in the Midnite SOC settings. Once you get all that stuff tweaked it should be ready to go and work pretty good.

Vic would tell you to label all your cells on your batteries and to take initial SG readings in a notebook, and then you have a reference to go by for the life of the batteries and can use that to also find cells in the future that may be getting low compared to the others . You can adjust your equalization according to that too over time.

Larry
Title: Re: SE Atlantic
Post by: BAndrews on December 25, 2016, 09:55:12 AM
Quote from: ClassicCrazy on December 24, 2016, 09:54:58 PM

You can start out with what you have for ending amps. The way I do it is to watch the SOC on Mymidnite along with the system amps . As the SOC counts up towards 100% then the system amps should start to level off. I also take a few specific gravity readings from the batteries to confirm that when it gets to 100  % SOC that the SG reading is what is recommended by the battery manufacturer.   You also need to set the battery efficiency in the Midnite SOC settings. Once you get all that stuff tweaked it should be ready to go and work pretty good.

Vic would tell you to label all your cells on your batteries and to take initial SG readings in a notebook, and then you have a reference to go by for the life of the batteries and can use that to also find cells in the future that may be getting low compared to the others . You can adjust your equalization according to that too over time.

Larry


Good to know.

I pulled up the Rolls "Battery User Manual" pdf and started reading.  Came across this on page 13:

"END AMPS OR RETURN AMPS

As batteries near full capacity the charge current drops. End Amps or Return
Amps generally refers to the lowest amount of current (Amps) running from the
charger when the batteries have reached full capacity and are no longer accepting
a charge. Some charges will measure the actual current output. If the charge
current drops to the End Amps or Return Amps set point, this will trigger the
charger to shut off. This setting is typically 2%-3% of the 20 Hr AH rating (C20)
of the battery bank. Rolls recommends setting this at 2% for new installations."

According to this, they are apparently wanting the battery settings as such:

(1) S550 = 428 AH
(2) Three serial strings of the S550 yields a pack with 1284  AH
(3) 1284 AH x .02 = 25.68 Amp cutoff


I can't get my head around a cutoff this high.  Maybe I'm making a calculation error?

Title: Re: SE Atlantic
Post by: ClassicCrazy on December 25, 2016, 01:09:15 PM
Looks like you did the calculations right as far as I can see.
As long as you have your classic set to use shunt instead of internal - so it uses the whizbang - put in that number for ending amps  and then keep an eye on the SOC - as it approaches 100% it should be around that end amps number if that is correct. Also confirm it with SG readings.

That seems to be about the only way to really know for sure.

I also compared your battery wiring to the ones in the link that I sent you . Yours would be the second shown of the 4 options. So better than the worst but not as good as the last two according to that person.

Larry
Title: Re: SE Atlantic
Post by: BAndrews on December 25, 2016, 07:30:58 PM
Quote from: ClassicCrazy on December 25, 2016, 01:09:15 PM
Looks like you did the calculations right as far as I can see.
As long as you have your classic set to use shunt instead of internal - so it uses the whizbang - put in that number for ending amps  and then keep an eye on the SOC - as it approaches 100% it should be around that end amps number if that is correct. Also confirm it with SG readings.

That seems to be about the only way to really know for sure.


I had not yet mentally closed the loop to experimentally verifiying the SG reading after shutoff.  It makes sense and is the only way I can think of to verify performance.  Thank you for the persistance.


Quote from: ClassicCrazy on December 25, 2016, 01:09:15 PM
I also compared your battery wiring to the ones in the link that I sent you . Yours would be the second shown of the 4 options. So better than the worst but not as good as the last two according to that person.

Larry


With three serial strings, I can duplicate the third option.  With the cost of these batteries, I should do that mod this week.  I can't conceive of any way that I could duplicate the forth option with three strings. 

Again ..... much thanks!
Title: Re: SE Atlantic
Post by: ClassicCrazy on December 26, 2016, 10:14:09 AM
As they say you need to make sure you get all those cables the same length for the third option.
It would be nice if batteries were simpler but they need constant oversight to make sure the invisiible things going on inside of them are what we want them to be .

My battery supplier would be happy to see that you left space between all the batteries - heat is one of their biggest enemies for long life.

Larry
Title: Re: SE Atlantic
Post by: CDN-VT on December 26, 2016, 07:12:59 PM
Nice & clean install .

VT
Title: Re: SE Atlantic
Post by: grgdgreek on January 22, 2017, 01:12:20 PM
Very nice:-)