Author Topic: A beginner who so so confused .. help?  (Read 1431 times)

TomW

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Re: A beginner who so so confused .. help?
« Reply #15 on: November 29, 2016, 01:07:26 PM »
Not sure how others would do it but I would parallel pairs of batteries and then put those pairs in series rather than 2 strings attached at both ends. If that makes sense? Using the shortest connections possible everywhere but especially between the parallel pairs.

This would make it much easier to isolate imbalances in battery capacity. I think.

Anyway those are my thoughts on that

Tom
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SouthPacific

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Re: A beginner who so so confused .. help?
« Reply #16 on: November 29, 2016, 01:56:43 PM »
Instead of doing a lot of playing with the panel angles and direction, I suggest you research 'Virtual Arrays'

Here is an example:
http://kb1uas.com/mnsforum/index.php?topic=2321.msg21910#msg21910

or do a more global search.  then you can use some of those extra PV's

Hello Westbranch,

Thanks for the reply.   :)

My design for this portion is really very simple.  I'm located on a pretty steep hillside, with absolutely no sun obstructions (except for the hill itself in morning sun).  But typically we still get the direct sun pretty early and have a clear shot of sun all the way into the ocean.  So, my thought was to build a solar platform that simply follows the roof-line and roof pitch.  I have drawn up a very rough sketch to try to show the design and attached it here.

The implementation of such a platform is very basic and simple.  A flat platform for only 8 panels. The platform will be able to be flat in the am hours, then tilt/pitch using only 3-4 extension rods and follow the existing roof pitch until it stops.  Then reset at night back to flat for the am again.

Since I have not put the top on the actual building yet, I can make the pitch conducive for the best solar angle as well.  And with only 8 panels, it should not be too tough.  There will also be a single pitch point on the north end that will be manually set for seasonal pitch.

Does this look do-able without much trouble?

Thanks,
SouthPacific

SouthPacific

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Re: A beginner who so so confused .. help?
« Reply #17 on: November 29, 2016, 02:15:46 PM »
Not sure how others would do it but I would parallel pairs of batteries and then put those pairs in series rather than 2 strings attached at both ends. If that makes sense? Using the shortest connections possible everywhere but especially between the parallel pairs.

This would make it much easier to isolate imbalances in battery capacity. I think.

Anyway those are my thoughts on that

Tom

Hello Tom,

Thanks again for the reply.

I'm a little confused on your answer here.  You say to parallel batteries, then series?  Not sure what you mean on that. 

The area I have the battery banks is limited, in which 8 fit perfectly in each "bay", so if I were to go 48 volt, the connection between the two banks would be about 4 feet.   The current configuration, I have custom made 2/0 cabling, almost all less than 12" long, most all probably 8" or so, just enough to go from battery to battery.  I knew I was going to have a lot of cabling, so I bought the actual raw cable, lugs and special big cable crimping tool, since I knew I was going to be doing a lot of this and wanted to keep the shortest distances of cable in the strings.

Attached is the configuration I found for one total bank at 48 volt, which is all series with the single parallel.

Thanks again,
SouthPacific
« Last Edit: November 29, 2016, 02:17:33 PM by SouthPacific »

TomW

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Re: A beginner who so so confused .. help?
« Reply #18 on: November 29, 2016, 02:54:01 PM »
I can't really explain better.

If you have 8 6 volt cells just find a new home for your 24 volt inverter and be smart and go to 48 volts if your panels and controllers can get there, of course.

In case you don't know this those batteries have the same energy capacity in 24 volt configuration or 48 volts. You will not lose or gain any capacity going 48 volts. 48 volts will be a more sane approach to using 8 6 volt units.

Do not make the mistake of designing around a "cheap" component that creates higher costs to actually use said component. Been there, done that and it can be a major headache and false economy.

I really don't care one way or the other but you seem to have decided on a path and I don't think I have energy or time to convince you to put it in neutral and think over the options with a view to long term success.

Don't take my word for it, look at the rest of the replies.

My only interest is seeing folks have success in their projects with a minimum of grief.


Tom
« Last Edit: November 29, 2016, 02:59:18 PM by TomW »
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Vic

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Re: A beginner who so so confused .. help?
« Reply #19 on: November 29, 2016, 03:50:38 PM »
Not sure how others would do it but I would parallel pairs of batteries and then put those pairs in series rather than 2 strings attached at both ends. If that makes sense? Using the shortest connections possible everywhere but especially between the parallel pairs.

This would make it much easier to isolate imbalances in battery capacity. I think.

Anyway those are my thoughts on that

Tom

Hello Tom,

Thanks again for the reply.

I'm a little confused on your answer here.  You say to parallel batteries, then series?  Not sure what you mean on that. 

The area I have the battery banks is limited, in which 8 fit perfectly in each "bay", so if I were to go 48 volt, the connection between the two banks would be about 4 feet.   The current configuration, I have custom made 2/0 cabling, almost all less than 12" long, most all probably 8" or so, just enough to go from battery to battery.  I knew I was going to have a lot of cabling, so I bought the actual raw cable, lugs and special big cable crimping tool, since I knew I was going to be doing a lot of this and wanted to keep the shortest distances of cable in the strings.

Attached is the configuration I found for one total bank at 48 volt, which is all series with the single parallel.

Thanks again,
SouthPacific

Only a little time,  just now.

 1.  Of course,  you will want a 48 V system.
 2.  The 48 V battery config for two strings of batteries is fine.   Two strings = not good,  but that is what you have now.   Single string of batts is much easier to manage,  and works better.
 3.  The four foot separation twix the two strings is NOT good.
 4.   You will want to have quite a bit more space for batteries for your future configuration.
 5.   Sevenish kWh consumption is quite a lot for an off grid system.
 6.  Strings of four of those PVs puts you in the territory of a Classic 200.   How about considering strings of three of your existing PVs?  Probably would be three strings of three,  instead of two strings of four.   You would need that Combiner/breakers with three or more strings.
 7.  YES,  sell the 24 V stuff,  and maybe those batteries,  too ...
And so on.   FWIW,   Vic
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!

SouthPacific

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Re: A beginner who so so confused .. help?
« Reply #20 on: November 29, 2016, 05:36:32 PM »
I can't really explain better.

If you have 8 6 volt cells just find a new home for your 24 volt inverter and be smart and go to 48 volts if your panels and controllers can get there, of course.

In case you don't know this those batteries have the same energy capacity in 24 volt configuration or 48 volts. You will not lose or gain any capacity going 48 volts. 48 volts will be a more sane approach to using 8 6 volt units.

Do not make the mistake of designing around a "cheap" component that creates higher costs to actually use said component. Been there, done that and it can be a major headache and false economy.

I really don't care one way or the other but you seem to have decided on a path and I don't think I have energy or time to convince you to put it in neutral and think over the options with a view to long term success.

Don't take my word for it, look at the rest of the replies.

My only interest is seeing folks have success in their projects with a minimum of grief.


Tom

Hello Tom,

Thanks again for the reply.  I'm not sure what made you think I have a "path" selected, but I can assure you I don't at this point and any and all advise is greatly appreciated.   :)

So you are saying my best route would be going 48v, but run 2 banks (8 X 6v batteries) and not parallel the two 48v banks?

My panels are the CSUN 305's and have many extras, so I can place into any style of configuration.  It's the controller that I am most confused about to make the most efficient setup in that regard.  Being a higher powered panel, finding the right controller is very important.  And I'm not looking to go go "cheap", but do want to find the best value for the long haul.

Thanks again,
SouthPacific

SouthPacific

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Re: A beginner who so so confused .. help?
« Reply #21 on: November 29, 2016, 06:02:10 PM »

Only a little time,  just now.

 1.  Of course,  you will want a 48 V system.
 2.  The 48 V battery config for two strings of batteries is fine.   Two strings = not good,  but that is what you have now.   Single string of batts is much easier to manage,  and works better.
 3.  The four foot separation twix the two strings is NOT good.
 4.   You will want to have quite a bit more space for batteries for your future configuration.
 5.   Sevenish kWh consumption is quite a lot for an off grid system.
 6.  Strings of four of those PVs puts you in the territory of a Classic 200.   How about considering strings of three of your existing PVs?  Probably would be three strings of three,  instead of two strings of four.   You would need that Combiner/breakers with three or more strings.
 7.  YES,  sell the 24 V stuff,  and maybe those batteries,  too ...
And so on.   FWIW,   Vic

Hello Vic,

Thanks again for the reply.   :)

Ok, so 48v it is.   :)  But I am a little unclear on your statement on the strings.  I'm using 2 bays, each holding 8 of the 6v Trojans, so when I series those it makes the 48v bank.  The parallel cabling going between the 2 48v banks I could get as short as about 2 feet with a little wall drilling.  You also mentioned "The 48 V battery config for two strings of batteries is fine.   Two strings = not good,  but that is what you have now".  Is there another configuration for a 48v system?  I have read about people using forklift batteries that are 2v cells.

I had never really checked into the typical loads of an off-grid system, but at 7.1 kw per 24/day, that will put the 30 day load around 215 kw per month.  When I checked a typical usage chart for housing, a 1 bedroom 750 sq ft apartment typically ran about 700-800 kw per month (more if using ac and such).  What does a typical off-grid system use for a house?  I am running 2 refrigerators and a large stand-up freezer, all being new and Energy Star, but most everything else is minimal.  1 TV and 2 laptops, router, etc and some LED lights the huge majority of the time.

Now going with the 48 volt setup, what would you recommend as to how many panels in what configuration (I have the CSUN 305's) and going into the combiner box and what would be the best controller(s) to run?  And for what I am wanting to run (since you said my usage for an off-grid system is high), should I had more storage..and if so, what would be the best configuration to use here?

Thanks again,
SouthPacific

Westbranch

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Re: A beginner who so so confused .. help?
« Reply #22 on: November 29, 2016, 07:39:07 PM »
SP, I just read all of today's posts right now and there is some confusion between all of us....  not sure but I think it is because we need to see a list that clearly tells us of all the bits you have and what you intend to buy...

The best place to put it is in you sig line. Please? 

As to the PVs I am saying use some (3 or 6) PV's FIXED in the AM position and similarly for the PM< FIXED.  Don't muck around with changing the direction daily, it's a PITA. Though you could have an adjustable option for different seasons...  or if you have > 3 days with poor solar insolation.

WHY Virtual Arrays?
 You say you have extra PV's handy, use them and orient them to optimize for the winter period as that is your critical time for making sure the batteries are fully charged...
In the summer you will have more input than you probably need, I sure do...

The battery layout you show is designed for ONE Charge Controller, not 2 as you state at the start of this thread.  It is called 8S 2P, 8 in series with 2 parallel strings (of 8 )

One of the issues is that those  Trojans are not very high in Ah rating, relatively...  look at my and others sig lines and you will see battery ratings above 500Ah and in 2 volt cells.  I have 900 Ah cells and that amount might work for you if you have 2 batteries on separate controllers feeding separate circuits...  or a single battery of ~2000Ah , depends if your loads are less than that (1000 Ah ) per day. Remember that you should not go below 50% State of Charge for the health of your battery...

hth
« Last Edit: November 29, 2016, 07:43:06 PM by Westbranch »
CL647 asleep
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CL 29032 V.2126-NW2097-GP2133 175A E-Panel WBjr, 3Px4s 140W > 24V 900Ah AGM,
2 Cisco WRT54GL i/c DD-WRT Rtr, NetGr DS104Hub Hughes 1100 Sat. Modem
Cotek ST1500 Inv  want a 24V WILLY Inverter
OmniCharge3024  Eu1/2/3000Gens
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SouthPacific

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Re: A beginner who so so confused .. help?
« Reply #23 on: November 29, 2016, 08:17:58 PM »
SP, I just read all of today's posts right now and there is some confusion between all of us....  not sure but I think it is because we need to see a list that clearly tells us of all the bits you have and what you intend to buy...

The best place to put it is in you sig line. Please? 

As to the PVs I am saying use some (3 or 6) PV's FIXED in the AM position and similarly for the PM< FIXED.  Don't muck around with changing the direction daily, it's a PITA. Though you could have an adjustable option for different seasons...  or if you have > 3 days with poor solar insolation.

WHY Virtual Arrays?
 You say you have extra PV's handy, use them and orient them to optimize for the winter period as that is your critical time for making sure the batteries are fully charged...
In the summer you will have more input than you probably need, I sure do...

The battery layout you show is designed for ONE Charge Controller, not 2 as you state at the start of this thread.  It is called 8S 2P, 8 in series with 2 parallel strings (of 8 )

One of the issues is that those  Trojans are not very high in Ah rating, relatively...  look at my and others sig lines and you will see battery ratings above 500Ah and in 2 volt cells.  I have 900 Ah cells and that amount might work for you if you have 2 batteries on separate controllers feeding separate circuits...  or a single battery of ~2000Ah , depends if your loads are less than that (1000 Ah ) per day. Remember that you should not go below 50% State of Charge for the health of your battery...

hth

Hello Westbranch,

Thanks again for the reply and I apologize for any/all confusion I have made in the thread.  I new at both PV and on-line threads/forums..I don't even know how to setup a tag line.

What I have learned so far here is going with a definite 48 volt setup.  So that portion is now set.

I'm a bit confused now even on my battery selection.  When doing a lot of research on places like YouTube, almost everyone was talking about going 6 volt batteries and Trojans were highly rated by many, hence my selection on which batteries I started with.  I did see a few people refer to using forklift batteries with the 2 volt cells, but those were people using old batteries and them reviving them, etc., so I was not real impressed with those.  I do wish I had gotten the larger Trojans than these smaller T105 RE's.  It seems I might as well sell them with all the other equipment for people here who have much smaller power needs.

Vic has mentioned that my power usage of 7.1 kw in a 24 hour time frame was pretty high for an off-grid system.  So I am now wondering what I need to fit my needs.  From other things I had read, it did not appear my usage to be even that of a standard small apartment, which averages around 700-800 kw per month and my base is around 215 kw .. so I thought I was doing ok, considering that is including 2 refrigerators and a large freezer (all new and Energy Star).  This, however, is only my base and NOT running my "extras" like stereo system w/powered subs, Jacuzzi bath tub (its not a multi person style unit), etc.  the 215 kw per month is strictly baseline with all my common things I use everyday.

So the only thing now for sure will be the solar panels themselves, which are the CSUN 305 Poly's.

To clarify my goal, is to build a system that is totally off-grid and properly run everything I want to run.  With such a fluctuation in power needs at different times, would designing a system with 2 battery banks be a good configuration, with 1 bank dedicated to run the "everyday" baseline items and a second bank to compensate and run the "extras", like the Jacuzzi bath tub, and music equipment, which these items would only be used maybe once a week at most (this is just me thinking out loud, so any suggestions/recommendations are very welcome).

And if changing batteries, what would be the best design for my application?

Again, basically everything is open.  The only for sure item is the panels themselves.  I can reconfigure everything else, even the panels, but I think the panels should work fine (if I am wrong on that, please let me know)

Most of the equipment I currently have is now off the list, since I am going to the 48v setup.  I do have the combiner box, which I think I can still utilize and all the solar panel wiring I have should be good (I have the 10 gauge MC4 connections, with multiple tails, up to 4 to 1) and that's about it for now.

Thanks again,
SouthPacific

Westbranch

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Re: A beginner who so so confused .. help?
« Reply #24 on: November 29, 2016, 09:03:45 PM »
here is the crux of your problem...

To clarify my goal, is to build a system that is totally off-grid and properly run everything I want to run

The first part of you statement is achievable but with limitations...

The objective, in RED, is the issue... you have outlined such high daily consumption levels, 7.1 KwHr NOT Kw, the time portion is important otherwise it is like saying I bought a 7 Kw generator and you left off the part where it burns fuel to make power...over time...

We use ~ 1.5Kwhr per day at the lake and live a comfortable life as we burn wood for heat and don't have a big 100W per channel stereo (it is still hooked to the grid in town) or a Jacuzzi for example...
and it took months to pare down what we would LIKE to what we NEED...  then you start adding a bit at a time to the analysis (spreadsheet) and evaluate the impact of the additional power needed.  You not only need to look at the loads in total but also the loads over time during the day and night. If 2 or 3 large loads are running simultaneously it has implications that may not matter if, say, your inverter is capable of 20Kw vs having a 2Kw inverter...and you have the storage to support it... or manual intervention is to be used to prevent killer surges occurring...

This is an exercise in self control and honesty. 
If you have unlimited resources you still have to start somewhere and take a first small step... NO?

Batteries:
Most of us here have started with a SACRIFICIAL set of batteries. 
WHY? Because 99% of first time solar users Will KILL their first set or 2 in short order.
Killing occurs eg, when one uses too much power at once by going to, say, 10% SoC
 or NOT replacing the usage asap, ie  no PV for 4 days and not running the generator on day 1...

You have to do this project systematically, start with the essential core and  then do another iteration with more loads... repeat as necessary

hth
CL647 asleep
KID FW1811 560W >C&D 24V 900Ah AGM
CL 29032 V.2126-NW2097-GP2133 175A E-Panel WBjr, 3Px4s 140W > 24V 900Ah AGM,
2 Cisco WRT54GL i/c DD-WRT Rtr, NetGr DS104Hub Hughes 1100 Sat. Modem
Cotek ST1500 Inv  want a 24V WILLY Inverter
OmniCharge3024  Eu1/2/3000Gens
West Chilcotin 1680+W to come

Vic

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Re: A beginner who so so confused .. help?
« Reply #25 on: November 29, 2016, 09:50:40 PM »

Only a little time,  just now.

 1.  Of course,  you will want a 48 V system.
 2.  The 48 V battery config for two strings of batteries is fine.   Two strings = not good,  but that is what you have now.   Single string of batts is much easier to manage,  and works better.
 3.  The four foot separation twix the two strings is NOT good.
 4.   You will want to have quite a bit more space for batteries for your future configuration.
 5.   Sevenish kWh consumption is quite a lot for an off grid system.
 6.  Strings of four of those PVs puts you in the territory of a Classic 200.   How about considering strings of three of your existing PVs?  Probably would be three strings of three,  instead of two strings of four.   You would need that Combiner/breakers with three or more strings.
 7.  YES,  sell the 24 V stuff,  and maybe those batteries,  too ...
And so on.   FWIW,   Vic

Hello Vic,

Thanks again for the reply.   :)

Ok, so 48v it is.   :)  But I am a little unclear on your statement on the strings.  I'm using 2 bays, each holding 8 of the 6v Trojans, so when I series those it makes the 48v bank.  The parallel cabling going between the 2 48v banks I could get as short as about 2 feet with a little wall drilling.  You also mentioned "The 48 V battery config for two strings of batteries is fine.   Two strings = not good,  but that is what you have now".  Is there another configuration for a 48v system?  I have read about people using forklift batteries that are 2v cells.

I had never really checked into the typical loads of an off-grid system, but at 7.1 kw per 24/day, that will put the 30 day load around 215 kw per month.  When I checked a typical usage chart for housing, a 1 bedroom 750 sq ft apartment typically ran about 700-800 kw per month (more if using ac and such).  What does a typical off-grid system use for a house?  I am running 2 refrigerators and a large stand-up freezer, all being new and Energy Star, but most everything else is minimal.  1 TV and 2 laptops, router, etc and some LED lights the huge majority of the time.

Now going with the 48 volt setup, what would you recommend as to how many panels in what configuration (I have the CSUN 305's) and going into the combiner box and what would be the best controller(s) to run?  And for what I am wanting to run (since you said my usage for an off-grid system is high), should I had more storage..and if so, what would be the best configuration to use here?

Thanks again,
SouthPacific

SP,

If you must run two parallel strings of batteries for a 48 V system,  then the diagram that you noted,  should be fine.   Long jumpers (read that you needed to use four foot jumpers to connect each half of the battery together) ...   that is quite long.

Off grid systems,  that rely on batteries,  usually need to be designed with as much energy conservation as possible.   7 kWh/day is quite a lot of consumption.   This has little to do with national averages for grid-powered systems.

What time of day that the energy needs to be supplies is an important piece of information.   Power supplied only from your PV array is much better than energy that needs to be supplied only batteries.   Having a relatively large PV array will help with this ...

Later,  Vic
« Last Edit: November 29, 2016, 10:50:13 PM by Vic »
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!

SouthPacific

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Re: A beginner who so so confused .. help?
« Reply #26 on: November 29, 2016, 11:47:33 PM »
here is the crux of your problem...

To clarify my goal, is to build a system that is totally off-grid and properly run everything I want to run

The first part of you statement is achievable but with limitations...

The objective, in RED, is the issue... you have outlined such high daily consumption levels, 7.1 KwHr NOT Kw, the time portion is important otherwise it is like saying I bought a 7 Kw generator and you left off the part where it burns fuel to make power...over time...

We use ~ 1.5Kwhr per day at the lake and live a comfortable life as we burn wood for heat and don't have a big 100W per channel stereo (it is still hooked to the grid in town) or a Jacuzzi for example...
and it took months to pare down what we would LIKE to what we NEED...  then you start adding a bit at a time to the analysis (spreadsheet) and evaluate the impact of the additional power needed.  You not only need to look at the loads in total but also the loads over time during the day and night. If 2 or 3 large loads are running simultaneously it has implications that may not matter if, say, your inverter is capable of 20Kw vs having a 2Kw inverter...and you have the storage to support it... or manual intervention is to be used to prevent killer surges occurring...

This is an exercise in self control and honesty. 
If you have unlimited resources you still have to start somewhere and take a first small step... NO?

Batteries:
Most of us here have started with a SACRIFICIAL set of batteries. 
WHY? Because 99% of first time solar users Will KILL their first set or 2 in short order.
Killing occurs eg, when one uses too much power at once by going to, say, 10% SoC
 or NOT replacing the usage asap, ie  no PV for 4 days and not running the generator on day 1...

You have to do this project systematically, start with the essential core and  then do another iteration with more loads... repeat as necessary

hth

Hello Westbranch,

Again thank you for your reply and patience with my lack of both knowledge and proper terminology.

When I referred to the Kill-O-Watt number, I simply looked at the watt meter and it read 7.1 kw at the end of the 24 hour test period, with only the basic equipment being metered in the line.  Can you clarify this setting?  Is that 7.1 kw use or 7.1 kw HOUR use?  I know that can be a big factor just by my lack of proper reading and terminology.  When I ran the test, it was a full like test that included the 2 refrigerators, the big freezer, then my single TV, two laptops, router and a few LED lights.  So I am unclear of that exact spec. 

That is why my line of thinking (just thinking out loud and I could be totally wrong) was to run two banks.  The 1st being for just the normal baseline everyday loads I know will be 24/7 and pretty constant as to total load.  Then use the 2nd bank as the "run the extras" like the music and Jacuzzi bathtub, etc. with all these things being rarely used, maybe once per week at most and most likely much less often.  However they can be big draws.  This way I will know what to expect from the 1st bank, being constant and much more predictable and the 2nd bank..well who knows until it is actually in use.  And I understand any battery bank should never be drained more than 50%, because that will destroy your bank very quickly.

I hope this brings a little more clarity.

Thanks again,
SouthPacific

SouthPacific

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Re: A beginner who so so confused .. help?
« Reply #27 on: November 29, 2016, 11:54:25 PM »


SP,

If you must run two parallel strings of batteries for a 48 V system,  then the diagram that you noted,  should be fine.   Long jumpers (read that you needed to use four foot jumpers to connect each half of the battery together) ...   that is quite long.

Off grid systems,  that rely on batteries,  usually need to be designed with as much energy conservation as possible.   7 kWh/day is quite a lot of consumption.   This has little to do with national averages for grid-powered systems.

What time of day that the energy needs to be supplies is an important piece of information.   Power supplied only from your PV array is much better than energy that needs to be supplied only batteries.   Having a relatively large PV array will help with this ...

Later,  Vic

Helli Vic,

So basically, if I run a larger solar array and use these major draw items (like the Jacuzzi bathtub and the music items) during say daylight and even peak solar times is much better, because I will be running from the PV array and not off the batteries?  So then use more panels and use those items during the daylight hours and this will save me greatly on the battery usage aspect?

Thanks again for the clarity. 

SouthPacific.

Westbranch

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Re: A beginner who so so confused .. help?
« Reply #28 on: November 30, 2016, 12:18:45 AM »
getting dark  here...  yes the term must have the hour included.. like I go 150 miles on my Mcycle vs I go 150 Mpg...

you are getting there and as Vic says ''  then the diagram that you noted,  should be fine.  ''

It can work for you but you need to be aware of the limitations...

And Vic also gave a different look at the timing of loads...  and ''opportunity  loads'' can be used to make use of power that otherwise would be ''lost'' as once your bank is nearly full, the CC will be throttling back on how much (Amps and/or Volts) is pushed into the bank... more later....

sleep on it... there is a lot to Solar 101 !
CL647 asleep
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dgd

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Re: A beginner who so so confused .. help?
« Reply #29 on: November 30, 2016, 05:28:44 AM »
SP
Looks like your getting lots of good advice here.
Definitely go 48v and invest in the largest batteries you can get to have just a single string of cells making the 48v.  From you dicussion on loads it would mot seem that a single string of L16 would not be sufficient. Something like 800ah cells would be nicer, if FLA types or 300/400ah if LifePO4 types

I also would not be in any hurry to sell off the spare PVs you have. The way things tend to work in this business is that spare PVs don't stay spare for long.

Dgd
Classic 250, 150,  20 140w, 6 250w PVs, 2Kw turbine, MN ac Clipper, Epanel/MNdc, Trace SW3024E (1997), Century 1050Ah 24V FLA (1999). Arduino power monitoring and web server.  Off grid since 4/2000
West Auckland, New Zealand