Need help choosing the right cable and breaker btwn Batts and Inverter

Discussion about OutBack Inverters in Off Grid Applications

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Shawn987
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Posts: 36
Joined: Wed Jan 01, 2020 6:26 am
My RE system: 1800-Watt 24-Volt Monocrystalline Solar Kit for Off-Grid Solar System which includes:
6 300 Watt panels.
MidniteClassic controller
2 12v AGM deep cycle batts (wired in series)
1 3000 watt 24v DC to 120 AC Aims Inverter.

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by Shawn987 » Sun Jan 12, 2020 11:04 pm

raysun wrote:
Sun Jan 12, 2020 7:47 pm

#2 Reconfigure battery to 48V @ 200AH. Replace 24V inverter with 48V inverter.

#3 Increase panel array up to 4.4kW.

Yeah, I'm fairly sure we're going to go with choices 2 and 3. But this won't happen right away. So would the Outback inverter work with my system? You know, when we discovered that the "kit" didn't come with an inverter I emailed Midnite solar and asked them if they had suggestions on inverters and I didn't really get an answer, as I recall. They've been okay with costumer service but the guy did keep suggesting we re-read the manual. Sooooo, I hope no one from Midnite lurks here, but I have to say their manual is not incredibly well written and didn't seem entirely up to date. Anyway, I didn't come here to dis them. I've heard their products are very good and I think they look very well made. I just wish a proper inverter had come with the system. On the other hand, maybe we'll like the one we have and it'll be fine for getting us started.

Anyway, now Sodamo has got me all primed and ready to buy two more of my Renogy batteries -- so that I ruin them uniformly (ha ha). Will two more batteries -- 2 strings of 2 @ 24v -- be okay with my present 6-panel system?
(and of course I will be vigilant with the battery monitor, don't worry!)
Lisa
in the S.F. Bay Area

sodamo
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My RE system: Totally off grid - Hamakua side, Big Island, Hi
36 Trina 280 & 16 Phono 250 in 48 volt array (fixed) 14080w
Radian 8048/4048
4 FM 80 charge controllers
FNDC w/3 shunts
Mate 3s
OpticsRE - MMKL - Ninole Hi
12 SimpliPhi 3.8
14Kw Kohler 14RESA

2FX3048T
Mate 3s
10Kw MEP 803a

Honda EU7000i

Davis VantagePro2 Wx Station
On line at: http://www.weatherlink.com/user/sodamo/
Location: Ninole, Hi

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by sodamo » Sun Jan 12, 2020 11:44 pm

HD email permit = receipt :grin:

As for getting shocked - awareness and safety. Done lots of work on my systems over the years. Probably 95% of time I want it de energized. That could range from throwing breakers to disconnecting wires and many combinations, could be local to area of system I’m working or a complete shutdown and system disconnected physically from house. In the rare instance that isn’t feasible I have nice heavy leather gloves and am especially aware of what and where I’m touching with appropriate tools. To be sure I will even probe with my multimeter. I also don’t mess with it in wet or rain unless emergency. No, never been shocked by my systems. But I have been shocked many times in my life. My Dad was an electrical contractor, I was his in house helper. Not unknown to have been working with a live wire, seen a number of tools flung across a room. Respect, aware, be safe.

Permits for an electrical system are not like cement work - Safety - not just yours but others. Not to be harsh, but I suspect your electrical knowledge isn’t much deeper than you solar knowledge of 2 weeks ago. You state having a goal to someday having your off grid system mesh with your city power. The good people on this forum cannot get you there. We don’t know enough detail and would make many assumptions about unseen stuff. This is especially true if you are in an old house. One of the reasons people hire a home inspector when buying a property. Yup, I was one of those and I seriously doubt some of the things I’ve seen were limited to the East Coast. I am pretty sure your power company will not allow a DYI hookup to their system, not without proper paperwork and inspection (liability issue). You need to find out their requirements and do so before you are too committed to your system. Might want to ask Aims about this inverter for your planned use. Of course it is your choice, but do be aware that should there be a problem in the future, fire, injury, etc you will likely find your insurance will not cover (fine print).
Please don’t take above as discouragement, rather be encouraged to do it right and do so from the getgo. Some else earlier mentioned doing so. Good advice.
David
Please visit http://vacation.ninolehawaii.com

sodamo
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Posts: 656
Joined: Mon Apr 03, 2006 1:55 am
My RE system: Totally off grid - Hamakua side, Big Island, Hi
36 Trina 280 & 16 Phono 250 in 48 volt array (fixed) 14080w
Radian 8048/4048
4 FM 80 charge controllers
FNDC w/3 shunts
Mate 3s
OpticsRE - MMKL - Ninole Hi
12 SimpliPhi 3.8
14Kw Kohler 14RESA

2FX3048T
Mate 3s
10Kw MEP 803a

Honda EU7000i

Davis VantagePro2 Wx Station
On line at: http://www.weatherlink.com/user/sodamo/
Location: Ninole, Hi

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by sodamo » Sun Jan 12, 2020 11:59 pm

Note on battery age. Need to look at manufacture date, not the date you acquired. As for ruining a set. Yep, ruined my first, sold my second with good life still left and 1st bank here at main house lasted almost 10 years of heavy use.

Midnight is a well respected company and fine products. As I recall it’s founder and Outback have a good history. And there are others as well. My first system was a hodgepodge of name brand products, all respected for what they built. But in those days we didn’t have the nicely integrated products like Raysun described with the Outback. So nice to pickup my iphone, ipad, computer anywhere I have been in the world, see realtime performance and make adjustments, even turn generator on and off. I’d never have a non integrated system again by choice.
David
Please visit http://vacation.ninolehawaii.com

Shawn987
Forum Whiz
Posts: 36
Joined: Wed Jan 01, 2020 6:26 am
My RE system: 1800-Watt 24-Volt Monocrystalline Solar Kit for Off-Grid Solar System which includes:
6 300 Watt panels.
MidniteClassic controller
2 12v AGM deep cycle batts (wired in series)
1 3000 watt 24v DC to 120 AC Aims Inverter.

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by Shawn987 » Mon Jan 13, 2020 12:15 am

Sodamo, as I said previously my husband worked as a mechanic and electrician for a number of years and this is not my field of expertise, so I'm not sure what my level of knowledge has to do with anything. As I said, I'm just trying to assist him in what little way I can by hearing input from people who've done this before. My husband has a demanding full time job so I'm trying to make this a little easier on him. Anyway you've made yourself very clear on this subject, so thanks very much.
Lisa
in the S.F. Bay Area

sodamo
Forum Czar
Posts: 656
Joined: Mon Apr 03, 2006 1:55 am
My RE system: Totally off grid - Hamakua side, Big Island, Hi
36 Trina 280 & 16 Phono 250 in 48 volt array (fixed) 14080w
Radian 8048/4048
4 FM 80 charge controllers
FNDC w/3 shunts
Mate 3s
OpticsRE - MMKL - Ninole Hi
12 SimpliPhi 3.8
14Kw Kohler 14RESA

2FX3048T
Mate 3s
10Kw MEP 803a

Honda EU7000i

Davis VantagePro2 Wx Station
On line at: http://www.weatherlink.com/user/sodamo/
Location: Ninole, Hi

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by sodamo » Mon Jan 13, 2020 12:50 am

“ Sodamo, as I said previously my husband worked as a mechanic and electrician for a number of years and this is not my field of expertise, so I'm not sure what my level of knowledge has to do with anything.”



Sorry, my apologies, just took you at your word:
“ neither of us have any prior experience with this”
“ He used to work as a mechanic for a grain mill and soldered many dozens of these copper eyelet connectors onto cables for the forklifts and jacks there”
Didn’t read that to mean electrician.

Drive on.
David
Please visit http://vacation.ninolehawaii.com

Shawn987
Forum Whiz
Posts: 36
Joined: Wed Jan 01, 2020 6:26 am
My RE system: 1800-Watt 24-Volt Monocrystalline Solar Kit for Off-Grid Solar System which includes:
6 300 Watt panels.
MidniteClassic controller
2 12v AGM deep cycle batts (wired in series)
1 3000 watt 24v DC to 120 AC Aims Inverter.

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by Shawn987 » Mon Jan 13, 2020 4:40 am

prior experience with "this" meaning setting up an off-grid solar system.
sodamo wrote:
Mon Jan 13, 2020 12:50 am
Drive on.
Good suggestion.
Lisa
in the S.F. Bay Area

raysun
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My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 Strings @ 2 Series)
Hyundai 355 watt panels (6 - 3 strings @ 2 series)
Honda EU7000is gas fuel generator

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by raysun » Mon Jan 13, 2020 5:57 am

Shawn987 wrote:
Sun Jan 12, 2020 10:35 pm
sodamo wrote:
Sun Jan 12, 2020 1:47 pm
adding battery part that is a small window to add more and can be detrimental if missed for lead acid batteries as the older ones will impact the newer.

I read mention of a device for integration to grid. I strongly suspect that would require some sort of approval. Inverter/chargers that interact with grid of recent vintage have been changed to meet certain regulatory requirements of CA and HI. Would tend to think your Aims doesn’t qualify.
Fortunately we haven't used the batteries at all yet, so I can order two more and avoid that problem of non-uniformity. I'm curious about something, how much charge is on these batteries when you get them? I've had them for a month now and I'm wondering if we need to get on with charging them.

{This message was edited for your protection!}
Shawn987 wrote:
Mon Jan 13, 2020 4:40 am
prior experience with "this" meaning setting up an off-grid solar system.
sodamo wrote:
Mon Jan 13, 2020 12:50 am
Drive on.
Good suggestion.
AGM batteries should receive a charge every 6 months to maintain health. You are in a unique position to assess state of charge relatively easily. This will be just about the only time this applies.

In batteries at rest (no load, open circuit) for at least 24 hours, voltage measured at the terminals correlates to state of charge. For AGM batteries, the following table can be used:
Screenshot_20200113-035009_Chrome.jpg
Measurements are temperature dependent. IIRC, the table corresponds to voltages at 75°F.

Using a quality voltmeter, measure voltage across the 12V block's + and - terminals. Refer to the table for state of charge. If at 90% or below, charge battery block with a quality charger.

Note, once the blocks are put into service and there is a load applied more or less continuously, this table no longer applies, as terminal voltage becomes a complex function of charge and load. That's where the "coloumb counter" battery monitors come in, measuring the flow of electrons into and out of the battery estimate SoC.
Last edited by raysun on Mon Jan 13, 2020 8:12 am, edited 1 time in total.

Shawn987
Forum Whiz
Posts: 36
Joined: Wed Jan 01, 2020 6:26 am
My RE system: 1800-Watt 24-Volt Monocrystalline Solar Kit for Off-Grid Solar System which includes:
6 300 Watt panels.
MidniteClassic controller
2 12v AGM deep cycle batts (wired in series)
1 3000 watt 24v DC to 120 AC Aims Inverter.

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by Shawn987 » Mon Jan 13, 2020 7:08 am

Raysun thank you so much for that. Glad that I can find that out pretty easily. There was no manufacturing date on them that I could find. If the date is on the bottom that doesn't help much - lifting these batteries is no fun even with two of us.
Lisa
in the S.F. Bay Area

raysun
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My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 Strings @ 2 Series)
Hyundai 355 watt panels (6 - 3 strings @ 2 series)
Honda EU7000is gas fuel generator

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by raysun » Mon Jan 13, 2020 8:14 am

I edited the post. AGM batteries lose between 1%-3% charge per month. So a battery in the 90% SoC range is a candidate for charging.

*NOTE TO SELF* - Coffee, THEN arithmetic.

Shawn987
Forum Whiz
Posts: 36
Joined: Wed Jan 01, 2020 6:26 am
My RE system: 1800-Watt 24-Volt Monocrystalline Solar Kit for Off-Grid Solar System which includes:
6 300 Watt panels.
MidniteClassic controller
2 12v AGM deep cycle batts (wired in series)
1 3000 watt 24v DC to 120 AC Aims Inverter.

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by Shawn987 » Mon Jan 13, 2020 1:26 pm

Great thanks for letting me know. I've also read recently that it's not so good to have the battery at topped level for more than a couple of days. Since mine is "on the shelf" and barely discharging perhaps it's a good idea not to charge all the way to 100%. Anyway I put an email into tech support at Renogy, we'll see what they say. Batteries are delicate things, aren't they?
Lisa
in the S.F. Bay Area

raysun
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Posts: 1249
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 Strings @ 2 Series)
Hyundai 355 watt panels (6 - 3 strings @ 2 series)
Honda EU7000is gas fuel generator

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by raysun » Mon Jan 13, 2020 2:05 pm

Shawn987 wrote:
Mon Jan 13, 2020 1:26 pm
Great thanks for letting me know. I've also read recently that it's not so good to have the battery at topped level for more than a couple of days. Since mine is "on the shelf" and barely discharging perhaps it's a good idea not to charge all the way to 100%. Anyway I put an email into tech support at Renogy, we'll see what they say. Batteries are delicate things, aren't they?
Drop one on your foot and you might change your mind about delicacy. ;)

Lead Acid Deep Cycle batteries are fine charged to 100% and then left to idle on the shelf.

Some battery operations are called "Float" service, where the battery is continuously trickle charged but only occasionally discharged. A UPS uses batteries in this way. Continuous float can be hard on a battery and specially formulated batteries have the longest life in this application.

When you talk to the Renogy folks, ask about the following:
* Recommended Charge current for Bulk Charge cycle
* Recommended Voltage for Absorb Charge cycle
* Recommended Time for the Absorb cycle
* Recommended End Amps for Absorb cycle
* Recommended Voltage for Float cycle
* Recommended Time for Float cycle
* Recommended Voltage for Equalization (Freshening) cycle
* Recommended Time for Equalization
* Recommended frequency (or condition) to run an Equalization cycle

Does your MC 150 charge controller have a temperature sensing cable for Temperature Compensated charging?

Shawn987
Forum Whiz
Posts: 36
Joined: Wed Jan 01, 2020 6:26 am
My RE system: 1800-Watt 24-Volt Monocrystalline Solar Kit for Off-Grid Solar System which includes:
6 300 Watt panels.
MidniteClassic controller
2 12v AGM deep cycle batts (wired in series)
1 3000 watt 24v DC to 120 AC Aims Inverter.

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by Shawn987 » Mon Jan 13, 2020 5:55 pm

raysun wrote:
Mon Jan 13, 2020 2:05 pm

Drop one on your foot and you might change your mind about delicacy. ;)
Oh mannn, you'd never walk again. They're like slabs of concrete and they have these razor thin carrying strings - ooww! I'll have my gloves on next time.

And yes, our MC 150 charge controller has a temperature sensing cable for Temperature Compensated charging. I can't wait to get this MC operating, it sounds like it's going to be a great assistant.

As to batteries I think it's dawning on me that keeping the batts healthy is the most challenging part in all this. I have a plan for how to do this though. I can't watch the monitor while I'm sleeping so I'll turn off whatever's plugged into the system. Genius, I know!
Lisa
in the S.F. Bay Area

raysun
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Posts: 1249
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 Strings @ 2 Series)
Hyundai 355 watt panels (6 - 3 strings @ 2 series)
Honda EU7000is gas fuel generator

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by raysun » Mon Jan 13, 2020 7:22 pm

Shawn987 wrote:
Mon Jan 13, 2020 5:55 pm
raysun wrote:
Mon Jan 13, 2020 2:05 pm

Drop one on your foot and you might change your mind about delicacy. ;)
Oh mannn, you'd never walk again. They're like slabs of concrete and they have these razor thin carrying strings - ooww! I'll have my gloves on next time.

And yes, our MC 150 charge controller has a temperature sensing cable for Temperature Compensated charging. I can't wait to get this MC operating, it sounds like it's going to be a great assistant.

As to batteries I think it's dawning on me that keeping the batts healthy is the most challenging part in all this. I have a plan for how to do this though. I can't watch the monitor while I'm sleeping so I'll turn off whatever's plugged into the system. Genius, I know!
Batteries and gravity don't mix. ;)

The 1st night after putting our system I went to bed exhausted and worried about overnight battery drain. I work with a start about 4:00 AM and immediately went to look at battery status. We'd consumed 3%. I told my wife later she could plug in more appliances.

There is a very useful tool - a Kill-a-Watt. It's an inexpensive meter that plugs into an electrical outlet and the appliance to be tested is plugged into it. Gives a wealth of info including power consumed. About $20 on Amazon and worth it.

Shawn987
Forum Whiz
Posts: 36
Joined: Wed Jan 01, 2020 6:26 am
My RE system: 1800-Watt 24-Volt Monocrystalline Solar Kit for Off-Grid Solar System which includes:
6 300 Watt panels.
MidniteClassic controller
2 12v AGM deep cycle batts (wired in series)
1 3000 watt 24v DC to 120 AC Aims Inverter.

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by Shawn987 » Tue Jan 14, 2020 4:32 pm

Raysun, how'd that work out in the long run? You had mentioned it's typical for people to wreck their first battery bank. Did you manage to be the exception to that rule?
Also, do battery's lives get shortened mainly due to over depletion or is there another potential cause that I should be mindful of?

Still waiting to hear from Renogy, in the meantime I ordered two more batteries and a batt monitor.

Question for Raysun or anyone. Will this be a sensible configuration: 6 300 watt panels (all of which get very good sun exposure) plus my 25v 3000 watt Aims inverter plus the four 200ah batteries (in two strings) Does this sound like a system capable of taking on a small daily task, ie. a couple of lamps in the evening and our small EnergyStar fridge. Are the odds good that my batteries will reach their intended life span? I mean provided I watch the monitor very closely and don't neglect that, ever!
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Lisa
in the S.F. Bay Area

pss
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My RE system: 8330 watts in three strings, Flexmax 60 x 3, Radian 8048A, GSLC load center, Mate 3S, Hub 10.3, FN-DC and 900 Amp, 48V Trojan T105-RE battery bank.

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by pss » Tue Jan 14, 2020 5:13 pm

Hi. This can be looked at in two ways: I'm thirsty, how much water can I drink or I have a quart of water, will that quench my thirst? In other words you cannot power a load using solar that exceeds the capacity of your solar system and you can only power loads that do not exceed the capacity of your solar system. (of course, this excludes generator and utility power generation). So you have 300 watt panels x 6 for a face plate rating of 1800 watts. In the real world of off grid, expect to produce 1800 x 8 x 0.75 in the summer and 1800 x 4 x 0.80 in the winter. Translated = about 10,800 watts in the summertime and about 5,760 watts in the wintertime. This is due to the inefficiency of off grid, the fact that your nameplate rating is calculated at 77 degrees fahrenheit in a laboratory under artificial sunlight, is about 10-14% less outdoors at noon in optimal sunlight and angle and decreases when the angle of the sun is less than optimal and decreases as the temperature rises above 77 degrees on the panel surface and increase as the temperature is less than 77 degrees on the panel surface in the sunlight. Then imagine that if your batteries were perfect, you could put in 1000 watts to them and take out 1000 watts. Life would be great. Except wires, breakers voltage changes, inverters, chargers all are less than 100% efficient. So say for every 1000 watts you put into a battery, maybe you generated 1100 watts of PV and got out from the battery 900 watts.
As for your batteries, they are rated at 200 amp hours for 10 hours. Most off grid batteries have a 20 hour withdrawal rating. You have 12 volts x 200 amps x 4 batteries sequenced in 2 strings so you have 400 amps for 10 hours at 24 volts or a capacity of 9600 watts fully charged. AGM batteries should probably not be discharged more than 30% of a full charge on a regular basis and probably not more than 50% in most cases (however, I defer to other experts on this forum as I use flooded lead acid batteries in my system, not AGM). A 50% discharge from full charge would give you 4800 watts of power at 24 volts. This means you have 200 amps of your 400 amp capacity. But since you will probably be inverting this to run your household items, you will be converting this from 24V DC to 120 V AC. When you do the math, you have 40 amps of power to use at 120 volts. So now you can figure if your TV uses 2 amps an hour, your laptop 1 amp an hour and your LED lights 0.5 amps an hour, you would be consuming 3.5 amps at 120 volts in an hour or 420 watts. And remember we said you have 4800 watts to use so 4800/420 = 11.42 hours of use. Now getting back to your solar output, we figured it is anywhere from 5,760 to 10,800 watts daily. So now you should have a good idea about your system use and can expect to fully charge your batteries each day and have enough inverter capacity to run a higher load for an hour or two if needed.

As for value, if you average over a year say 8.2 kWh of daily production at a utility price of 28 cents per kWh, you are generating $2.29/day or about $838.04 of power annually. And of you spent say $3500.00 on your system, you will break even after a little more than 4 years and be in the black the next 16-25 years, less battery costs over time. Still a good deal.

provo
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My RE system: Sixteen Evergreen EC-120
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Location: Sierra foothills

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by provo » Tue Jan 14, 2020 5:35 pm

Shawn987 wrote:
Tue Jan 14, 2020 4:32 pm
Will this be a sensible configuration: 6 300 watt panels (all of which get very good sun exposure) plus my 25v 3000 watt Aims inverter plus the four 200ah batteries (in two strings)
I'm still wondering about charging your batteries and running loads when there's no sun. Have you found a battery charger, since the Aims doesn't include that function? Do you want to power a charger from a generator, or (what I do), use PGE to charge your batteries (still with a separate charger) when needed, with (maybe) a backup generator for PGE outages.

There's yet another approach -- return the Aims and get an Outback Inverter/Charger, which will do both functions in one unit.

Shawn987
Forum Whiz
Posts: 36
Joined: Wed Jan 01, 2020 6:26 am
My RE system: 1800-Watt 24-Volt Monocrystalline Solar Kit for Off-Grid Solar System which includes:
6 300 Watt panels.
MidniteClassic controller
2 12v AGM deep cycle batts (wired in series)
1 3000 watt 24v DC to 120 AC Aims Inverter.

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by Shawn987 » Tue Jan 14, 2020 6:01 pm

Pss, thanks for that great analysis. I think this will work out for me if I'm careful and make sure everything is being taken care of properly. After reading thru several thread on this forum I've decided to keep my system small and totally off grid. My initial reason for having a solar back up was to get me thru the black outs here, so I can keep working and have a light or two on while the power is out. I think my present configuration will meet that goal. It may pay for itself over time but even if it doesn't this is a fun and interesting challenge for me.
Lisa
in the S.F. Bay Area

Shawn987
Forum Whiz
Posts: 36
Joined: Wed Jan 01, 2020 6:26 am
My RE system: 1800-Watt 24-Volt Monocrystalline Solar Kit for Off-Grid Solar System which includes:
6 300 Watt panels.
MidniteClassic controller
2 12v AGM deep cycle batts (wired in series)
1 3000 watt 24v DC to 120 AC Aims Inverter.

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by Shawn987 » Tue Jan 14, 2020 6:18 pm

Provo, I am thinking when the batteries don't get a good daytime charge due to weather I'll not use the lamps that are plugged into it and just use the ones that are plugged into PGandE. We do have a couple of chargers here, so if the batteries get too low... Also, if you keep large water bottles in your freezer and fridge you can turn it off at night and everything still stays frozen/cold. Have you ever done that? This is my practice because I don't like the fridge kicking on when I'm trying to sleep. I live in a very small house. We do have a gas generator here if we need it. As to the inverter, I think since it has that advantage of drawing two thirds less energy than similar inverters, I'd like to go with it and see how it works out.

Do you live in the bay area? Edit: Oh I see you live in the sierra foothills. I'd love to move there someday. Almost did a few years ago, actually. It is beautiful up there!
Lisa
in the S.F. Bay Area

provo
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Posts: 173
Joined: Thu Jul 27, 2006 4:34 pm
My RE system: Sixteen Evergreen EC-120
(4 strings, total 1920W)
Eight Rolls S-550 (2 strings, total 800Ah @ 24V)
One FM80
One VFXR3524A
Mate3s
Trimetric
Location: Sierra foothills

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by provo » Tue Jan 14, 2020 7:32 pm

Yeah, I grew up in San Jose, worked at Apple 15 years and retired to the "family compound", as we jokingly refer to it. Built an off-grid strawbale house and just got PGE in 2018 after 11 years off the grid. It's a gorgeous area.

Well, have fun with your project -- be sure to turn off those loads BEFORE the sun disappears for a week :grin: !

raysun
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Posts: 1249
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My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 Strings @ 2 Series)
Hyundai 355 watt panels (6 - 3 strings @ 2 series)
Honda EU7000is gas fuel generator

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by raysun » Tue Jan 14, 2020 8:26 pm

Shawn987 wrote:
Tue Jan 14, 2020 4:32 pm
Raysun, how'd that work out in the long run? You had mentioned it's typical for people to wreck their first battery bank. Did you manage to be the exception to that rule?
Also, do battery's lives get shortened mainly due to over depletion or is there another potential cause that I should be mindful of?

Still waiting to hear from Renogy, in the meantime I ordered two more batteries and a batt monitor.

Question for Raysun or anyone. Will this be a sensible configuration: 6 300 watt panels (all of which get very good sun exposure) plus my 25v 3000 watt Aims inverter plus the four 200ah batteries (in two strings) Does this sound like a system capable of taking on a small daily task, ie. a couple of lamps in the evening and our small EnergyStar fridge. Are the odds good that my batteries will reach their intended life span? I mean provided I watch the monitor very closely and don't neglect that, ever!
That system will work just fine for your initial usage scenario. The battery monitor will be your lifesaver and the service-life saver of the battery.q

Good sun exposure is good, but "good sun exposure" is subjective. There are online tools that will take your address as input and give you a detailed estimate of sun exposure in measured values at monthly and even weekly resolution. You can calculate solar harvest and have baseline working numbers for your array. Read up on the impact of panel placement, shading, etc. Just spitballing, the 6 x 300 = 1.8kW array might harvest power for 6-8 hrs/day in winter and 10-12 hrs/day in summer. Daily production might be near zero on stormy day, and 8-12 kWH on a sunny day in summer.

You will get a first hand measure of actual solar harvest daily from your charge controller / battey monitor. The monitor should help track charge drawn from the battery. You'll know in short order what your daily power consumption is, so what you need to put back. Plan on one discharge/charge cycle to occur every 24 hours. Your "at home" cycle. You can plan an "away from home" cycle for weekend trips, vacations, etc., that may have lower daily discharge and longer charge cycles. The battery can hang around between 100% and 50% SoC for a week or two without undue wear as long as its fully recharged promptly on return. A "freshening charge" is often recommended by the battery mfgr after such an extended period of partial SoC.

Makeup charging using a 2nd source will become SOP as well. The system will become convenient, useful, and will see increased demand during at home cycles most certainly. Energy debt should be paid promptly. As mentioned, practical sources are grid and generator using an AC charger. Extended grid outages and low solar output days will make the generator option desirable.

Since you are in an area that has reliable grid power you have the latitude to "ease into" the solar plus storage usage and maintenance disciplines. The reward for mastering the knack is you can use it more, remove loads from the grid, and get to put a happy sticker on the electric bill. It all doesn't need to happen at once, as I'm sure you know, and are planning for.

I'd say your demand floor to be 1.5 - 2.5 kWH/day. You might make it an exercise to guarantee the refrigerator and emergency lights runs off grid 7x24x365 and system manage to that goal. (Challenging you to not do the hippy-in-the-woods refrigerator on a timer thing.) Minor loads like computer, phone chargers, etc., become priority "B" loads. Goal is to balance consumption to harvest. You'll get the hang of it and learn to manage your battery well.

Did I ruin my first battery? TBH, no, but I pre-ruined enough batteries before putting in my system to make up for it.

Shawn987
Forum Whiz
Posts: 36
Joined: Wed Jan 01, 2020 6:26 am
My RE system: 1800-Watt 24-Volt Monocrystalline Solar Kit for Off-Grid Solar System which includes:
6 300 Watt panels.
MidniteClassic controller
2 12v AGM deep cycle batts (wired in series)
1 3000 watt 24v DC to 120 AC Aims Inverter.

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by Shawn987 » Tue Jan 14, 2020 10:17 pm

Thank you all for your great and entertaining responses. This is definitely a challenge but at the same time a lot of fun.

I still didn't hear back from Renogy so their costumer service doesn't get gold stars - but! - I got a good multimeter on my batteries today and one is at 12.89v and the other at 12.91. Being that 13 is "full" that suggests the batteries (which I've had over a month) are very new! Let's hear it =D> for Renogy and Home Depot!

Provo 11 yrs off grid wow... What an incredible way to live. I really want to move out there some day.
Lisa
in the S.F. Bay Area

Shawn987
Forum Whiz
Posts: 36
Joined: Wed Jan 01, 2020 6:26 am
My RE system: 1800-Watt 24-Volt Monocrystalline Solar Kit for Off-Grid Solar System which includes:
6 300 Watt panels.
MidniteClassic controller
2 12v AGM deep cycle batts (wired in series)
1 3000 watt 24v DC to 120 AC Aims Inverter.

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by Shawn987 » Tue Jan 14, 2020 10:26 pm

P.S. Raysun, yes I'll ask the guy at Renogy all those questions about charging and equalizing, but I think maybe one at a time.

I don't want him to put me on email block :wink:

EDIT: Actually what I should do is ask him if he has any pdf downloads he can send me on this. Sort of odd, I thought, that these batteries came with no info whatsoever on care.
Lisa
in the S.F. Bay Area

raysun
Forum Emperor
Posts: 1249
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 Strings @ 2 Series)
Hyundai 355 watt panels (6 - 3 strings @ 2 series)
Honda EU7000is gas fuel generator

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by raysun » Tue Jan 14, 2020 10:31 pm

Shawn987 wrote:
Tue Jan 14, 2020 10:26 pm
P.S. Raysun, yes I'll ask the guy at Renogy all those questions about charging and equalizing, but I think maybe one at a time.

I don't want him to put me on email block :wink:
LOL! All of those are standard specifications for three stage charging, plus equalization charging, a separate maintenance step. They should have a document that details their recommendations. The online manual was a bit sparse.

Shawn987
Forum Whiz
Posts: 36
Joined: Wed Jan 01, 2020 6:26 am
My RE system: 1800-Watt 24-Volt Monocrystalline Solar Kit for Off-Grid Solar System which includes:
6 300 Watt panels.
MidniteClassic controller
2 12v AGM deep cycle batts (wired in series)
1 3000 watt 24v DC to 120 AC Aims Inverter.

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by Shawn987 » Wed Jan 15, 2020 4:12 am

Yes I'll get on the guy for this info. I actually received no manual at all with the batteries - there is a little info on the battery's special features on the Home Depot page but nothing about proper charging methods; not much about care.

Speaking of customer service, the Aim's people are totally non responsive when you email their tech support. Now I'm starting to contemplate returning the inverter -- I got it at HD so I still have that option.
Lisa
in the S.F. Bay Area

raysun
Forum Emperor
Posts: 1249
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 Strings @ 2 Series)
Hyundai 355 watt panels (6 - 3 strings @ 2 series)
Honda EU7000is gas fuel generator

Re: Need help choosing the right cable and breaker btwn Batts and Inverter

Post by raysun » Wed Jan 15, 2020 8:18 am

If you return the inverter, and want to explore options, I'm sure there would be lots of input from this group! LOL!

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