Advice appreciated on re-doing our off-grid home system

[seneysolar]

Okay thanks will look into the EG4 PowerPro and Midnight.

Current batteries are Rolls open lead acid (890 ah). I should have clarified - when I said they are going down quick I meant the battery life. When they get a full charge on a fully sunny day, when the PV stops generating for the day the batteries are only about 70% charged. And with lead acid we're only supposed to use to 50% so it's a small window. The capacity has been going down consistently. I think they are sulfated. I have been in lots of communication with the battery manufacturer and controller/inverter manufacturer. It could be a combo of things - we originally ordered the system when we started building the house but things got delayed so batteries sat longer than expected, then got the system set up in middle of winter and got no sun for months so we charged a lot with a generator and the generator we were originally sold with the solar package was undercharging the batteries. Battery manufacturer gave us recommendations to change settings on the controllers/inverter to try to get the battery capacity back up but it didn't work. They say the AIMS equipment consistently undercharges but AIMS warned changing the settings from their default could affect the batteries worse which it seems to have done. So we're chalking it up to a learning experience and switching to lithium.

Summer energy consumption is between 10 to 15 KW per day. We have a 12KW inverter and it generally shows using 3-4% unless something like the well pump or microwave comes on which uses a lot for a short period. In winter we use more - between 15-20kWh.

Id haul these back to civilization and use grid power to do a complete charge, then equalization charge, for hours and hours....

Did the charge controller switch out of "bulk" too soon?

What did they tell you to use for cc settings?

As @Hedges said these are top quality batteries that should last a while. But i fear you are correct that they spent alot of time discharged without getting charged back up to full.

 

[Dooug]

You may want to look into the duty charges getting them north of the border. When I get back to my laptop I'll try and get that information from a conversation I had last year.

 

[Hedges]

Possibly Midnight batteries will skirt that duty. Not sure, cells would be from China.
There is duty-free for Canada made products imported to US, so I would think same going other way.

Are duties paid for China --> US --> Canada higher than China --> Canada ?

 

[OffGridBC]

Thank you all for your replies, much appreciated.

7kW (STC) of PV in summer ought to supply at least the ~ 21kW of PV needed to cover 15kW consumption and 70% round-trip efficiency. Charging takes hours of bulk at 0.12C and a couple hours absorption. If not fully charged, maybe voltage (or current) settings not correct. Or power harvesting way below the expected 5kW +/- from those panels.

We're getting almost full (sometimes it surges over) the rated wattage of panels in full sun so it's not that. We're getting over 30KW per day in summer no problem by the time charge controllers go into float.

Winter you might get only 2 hours effective sun, depending on exposure and angle. I'd think panels sloped to maximize winter is what's needed.

We change angle of panels in winter to maximize. Before we moved here google said this area gets the most days of sun/year in BC so we expected more, but in winter sun is scarce, not much solar generation. We run generator every day in winter.

Possibly cells need equalization. What voltage per cell (or per 6V or whatever is accessible to measure)?
What specific gravity per cell?

(at least some) Rolls batteries are super-premium quality and expensive, could give 20 years service.
Try to fully charge, as a pack or as individual batteries, test specific gravity, equalize as required.

You're from the frozen north. Lead acid works there, so long as not left discharged to freeze. Lithium works (except in extreme cold) but has to be above freezing. Near freezing charge rate can be 0.05C to 0.15C, comfortable temperature can be 0.5C maybe higher.

We have 16 batteries, 6V each, 48V system. I measured voltage and specific gravity a lot throughout last year and especially this past winter when we tried equalizations, subsequent full charges with the generator (we don't have grid access here), and different setting changes recommended by the battery manufacturer but the readings never went up but actually down a bit. After all that I noticed when I top up the distilled water in the batteries that the fluid is brownish in color rather than clear like it used to be. So we may have pushed them too far.

Batteries are indoors in a closed cabinet with 24/7 ventilation. I don't think we got the premium batteries but was definitely expecting them to last longer, though as seems to be the consensus it was probably a combination of different circumstances of them sitting longer than expected at the beginning (we were encouraged to buy them early because it was during covid when things were hard to get but then they arrived quick and we weren't ready for them), not getting fully charged properly through the first winter, and controllers not fully charging either. Our controller default setting for lead acid is 58v bulk and 54 float, cannot set absorption time as it's done automatically. Rolls tech support said they were consistently being undercharged at those settings and that the absorption time it was doing was too short, so I changed it to 60v bulk / 54 float as they recommended but neither the controllers nor inverter would push it that far (quit before it got there). So we pushed it manually with the generator in winter but batteries got worse. So we decided to cut our losses and look for new batteries.

Id haul these back to civilization and use grid power to do a complete charge, then equalization charge, for hours and hours....

Did the charge controller switch out of "bulk" too soon?

What did they tell you to use for cc settings?

As @Hedges said these are top quality batteries that should last a while. But i fear you are correct that they spent alot of time discharged without getting charged back up to full.

Don't have access to grid power at current location, would have to haul them somewhere. See above for explanation.

 

[OffGridBC]

Possibly Midnight batteries will skirt that duty. Not sure, cells would be from China.
There is duty-free for Canada made products imported to US, so I would think same going other way.

Are duties paid for China --> US --> Canada higher than China --> Canada ?

You may want to look into the duty charges getting them north of the border. When I get back to my laptop I'll try and get that information from a conversation I had last year.

Good suggestion. We are only an hour from Montana and go to pick up things fairly often (once a month). There is no duty on items made in the US or Mexico but for products or components made in China or elsewhere they charge duty. Depends on the mood of border agents too. I was planning to order to have shipped to Montana and pick up there because still typically cheaper than getting it here.

 

[seneysolar]

If kept warm, going lithium will be a great improvement.
You have another learning curve ahead of you with different charge profile and settings for lithium, but you sound like you are willing and eager to learn.
Being completely off grid i recommend to familiarize yourself with the low and high voltage protection features of the specific battery you choose and have a process to recover it if it happens.
I carry an Iota DLS-54-13 power supply on my service truck for this reason. Some charge controllers/batteries need to be woke up after a bms shut down.

 

[OffGridBC]

If kept warm, going lithium will be a great improvement.
You have another learning curve ahead of you with different charge profile and settings for lithium, but you sound like you are willing and eager to learn.
Being completely off grid i recommend to familiarize yourself with the low and high voltage protection features of the specific battery you choose and have a process to recover it if it happens.
I carry an Iota DLS-54-13 power supply on my service truck for this reason. Some charge controllers/batteries need to be woke up after a bms shut down.

Oh man, thanks for the heads up. I was hoping (maybe naively) that lithium batteries were easier - connect and all would run smoothly. We've had our share of issues with our current system. I do want to learn so I understand how it works. If the controller/inverter are set to make sure the batteries don't get below or above the low/high voltage, the batteries or controller can still shut down? I don't want to go through buying new batteries to have them fail in a short time again like our current batteries, so any advice is appreciated on a good battery management system. And recommended equipment such as batteries/controllers that are good quality & work well together, as I don't have any experience/knowledge of lithium. A few people mentioned Midnite coming out with new batteries so I contacted them and they said mid-august. I will look into the battery charger you mentioned. Thanks again.

 

[seneysolar]

Oh man, thanks for the heads up. I was hoping (maybe naively) that lithium batteries were easier - connect and all would run smoothly. We've had our share of issues with our current system. I do want to learn so I understand how it works. If the controller/inverter are set to make sure the batteries don't get below or above the low/high voltage, the batteries or controller can still shut down?

For the most part, everything will probably run smoothly. You may have to tweak settings by .1 or .2 from mfg settings not a big deal.
Sometimes high use systems that do repetitive short generator charging, like in the winter, get cells out of balance. Lithium charges quickly (a couple hours) but every once in while, if not getting much sunlight, id do a longer charge to give the cells time to balance.

An example is this post going on right now-

EG4 imbalance

You just need to understand whats hapens and how to correct it if 1 cell bumps into that high/low limit. It may happen a few times as you get started, but once you get everything set, you're good!

I don't want to go through buying new batteries to have them fail in a short time again like our current batteries, so any advice is appreciated on a good battery management system. And recommended equipment such as batteries/controllers that are good quality & work well together, as I don't have any experience/knowledge of lithium. A few people mentioned Midnite coming out with new batteries so I contacted them and they said mid-august. I will look into the battery charger you mentioned. Thanks again.

Definitely worth seeing what midnite has to offer come fall. Dont be surprised if its delayed, but it will be a quality product.
EG4 batteries are pretty good, might be the best value in a server rack battery.
Also look at SOK for comparison.
Personally id stay away from battle born, just not worth the money.

 

[Quattrohead]

The EG4 indoor Power pro batteries are going to be your best bang for your buck. Couple them with an EG418K PV or pair of 6000XP inverters and you will have the most sturdy power supply you need for your new home.
They have high voltage PV inputs so you can string 10 panels in series easy enough.

 

[OffGridBC]

The EG4 indoor Power pro batteries are going to be your best bang for your buck. Couple them with an EG418K PV or pair of 6000XP inverters and you will have the most sturdy power supply you need for your new home.
They have high voltage PV inputs so you can string 10 panels in series easy enough.

For the most part, everything will probably run smoothly. You may have to tweak settings by .1 or .2 from mfg settings not a big deal.
Sometimes high use systems that do repetitive short generator charging, like in the winter, get cells out of balance. Lithium charges quickly (a couple hours) but every once in while, if not getting much sunlight, id do a longer charge to give the cells time to balance.

An example is this post going on right now-

EG4 imbalance

You just need to understand whats hapens and how to correct it if 1 cell bumps into that high/low limit. It may happen a few times as you get started, but once you get everything set, you're good!

Definitely worth seeing what midnite has to offer come fall. Dont be surprised if its delayed, but it will be a quality product.
EG4 batteries are pretty good, might be the best value in a server rack battery.
Also look at SOK for comparison.
Personally id stay away from battle born, just not worth the money.

Thank you for your recommendations, and everyone who has responded. Your responses have made me feel a lot better that once I get the right components it should all work a lot smoother (aside from some minor tweaks and learning curve). I have been researching batteries the last few days. Midnite says theirs will be available in August but if they are delayed I'm not sure I can wait. Our batteries are currently just making it through a night after a full charge so I want to replace them before days get shorter closer to winter.

I have been looking at the following options:
- LifePower4 - would start with 6 for 30 kWh - batteries are available but rack is backordered (same at Signature Solar)
- EG4 indoor wall mount 280 Ah 14.3 kWh (would get 2 or 3)
- RuiXu batteries - I have seen some posts on the forum that these are good. Either the 30 kWh rack (currently on sale) or their 16 kWh x2 though these will be indoors

Any thoughts on best battery to go with?

Also, I want to make sure I get batteries that will work with other components. A number of people here recommended I keep the AIMS 12KW inverter (specs here). If I do that rather than replacing everything with two 6000 XP's...

- Will all of the above batteries work with the AIMS inverter? I read all the specs but I'm not quite sure.
- I need to replace my 2 charge controllers for larger voltage ones (as per explained in the initial post). I'm not sure the best ones to get. Have been looking at EG4 controllers, Victron 250/100, or Midnite Classic (though amps on this seem too low). Again, not sure which will work best with any of the above batteries.

Also, not sure my math is correct for which items work best with the other components and the solar panels I have. Panel specs are attached (have 16 total, in 2 sets of 8 - each set goes to a charge controller. Currently in strings of 2 but need to be re-wired to increase voltage and decrease amps, thus the need to get new controllers).

Any advice is appreciated on the above questions and to make sure all the components will work together properly. That is the biggest issue we have had so far, so I don't want to be replacing anything again in the near future once we get new stuff. Thanks again.

 

[Quattrohead]

The simple way to make sure it all works together is to get AIO and batteries from the same company. Unfortunately the 6000xp is on back order for a while.
The aims inverter will work with any battery, just in dumb mode. As long as you can set the bulk and float voltage to suite the battery either on the aims for grid charge or whatever mppt you end up with.
Only try new to market products from far away lands if you are brave

 

[seneysolar]

Check out this RuiXu thread-

RuiXu

Will is doing a test/review on these batteries right now.

 

[OffGridBC]

Midnight will have batteries of both sizes, I think.

I contacted Midnite and they said new batteries will be available about mid-August but couldn't provide price or specs yet. However, I used their online sizing tool and it says my array power wattage is over what the Classic 250 can handle so I would still need a different brand controller.

Communications with battery can allow for better cell balancing (slow down charge to let BMS do its work). If sticking with your existing inverter, that may not have communications. See if you can get charge controller and battery that play together.

Yikes, have been learning that our current inverter may not have communications with batteries. I contact Ruixu re their batteries and they replied "This inverter is not suitable for our battery, in fact it is not suitable for any 16-string LFP battery. The inverter's Low Battery Trip is too low." So if not suitable for any 16-string LFP battery will it work with any EG4 batteries? If I understand correctly, the LifePower4 is 16-string? Not sure about their PowerPro (I'm having trouble understanding all the battery stuff). Our inverter manual says low battery trip point is 40 or 42 VDC for utility priority or 42 or 46 VDC for battery priority. Those are the only low battery trip point settings available. Would an option be to keep the inverter for running load from batteries but charge in winter through chargeverters and get matching brand batteries and controllers (ie EG4 as their controllers work with our panel specs)? Sorry a few questions here.

EG4 has PowerPro batteries, which are based on 280 Ah so 14kWh each. Might be better than larger number of 100 Ah 5kWh batteries.

Been looking at both of these. PowerPro batteries are currently available from Current Connected whereas LifePower4 in the 6-server rack are backordered. I don't understand the difference between the 2 types of batteries, other than if I get 2 PowerPro it would be 560 Ah / 28 kWh vs 6x LifePower4 which would be 600 Ah / 30.72 kWh. Which battery is better and why?

You have 7200W (STC) of PV now. What does an insolation calculator say they should produce?
What is your consumption?
You may need more PV, or energy conservation.

Insolation calculator says 30+KW from May to August (40KW in July) down to 4874 to 6753 Watts/day in winter (Nov to January). That's definitely what we've seen. Consumption is approx 20KW/day. We're working on some energy conservation but we work at home so run stuff all day, and have a greenhouse with fans that run 24/7. What we have learned over the last year is we don't have to run the generator barely ever between April and October, if at all (cloudy days still generate enough power), but almost every day from Dec to Feb. If we add more panels it would help a bit, moreso the shoulder seasons, but we get almost no sun in winter. We're in the mountains and between snow & clouds our panels generate barely anything. We may run powerlines at some point in future but for now we're 100% off-grid. So we got used to running the generator for a few hours every day in winter and while we do that we run all the big power stuff at same time (heat, laundry, etc) so that when generator is off our power consumption is minimal. More batteries would help extend the time between charging in winter. I assume that means also adding more panels so that PV can charge the batteries fully in summer as well if battery bank is larger.

The simple way to make sure it all works together is to get AIO and batteries from the same company. Unfortunately the 6000xp is on back order for a while.
The aims inverter will work with any battery, just in dumb mode. As long as you can set the bulk and float voltage to suite the battery either on the aims for grid charge or whatever mppt you end up with.

We have the 12KW AIMS inverter which works great but it has very minimal settings - select battery type and that's it, does the rest automatically. They don't have a setting for lithium so it must be "charge off". I can't find anything regarding lithium in the manual so I will have to call them. As you said, it seems like the simplest thing may be to buy same brand of everything.

Check out this RuiXu thread-

RuiXu

Will is doing a test/review on these batteries right now.

Thank you for the RuiXu link. They sound like good batteries but I contacted them and they said they won't work with my inverter (see above). I was going to call AIMS to double-check but RuiXu also said they aren't yet certified for Canada and we have to go through inspection as it's a new home.

Summary of Above:
- Originally a number of people recommended to keep the AIMS inverter but I'm not sure which batteries it will work with - what do I look for in the battery and inverter the specs to know for sure? Is it the low battery trip point as referenced above?

- Would an option be to keep the inverter for running load from batteries but charge in winter through chargeverters and get matching brand batteries and controllers (ie EG4 as their controllers work with our panel specs)? Or better to replace everything with one brand?

- If replace everything with all one brand...
- It looks like EG4 batteries with two 6000 XPs might be best as far as working with our panels. In that case, which EG4 battery type is best? PowerPro, LifePower4, or LL-S?
- Signature Solar has inverters in stock, and Current Connected has EG4 wallmount batteries in stock (neither have both), and neither have the PowerPro4 6X rack in stock. Trying to find out when will be available, or if I should get the inverters from SS and wallmount batteries from CC and be done - or is that a bad idea to get from different companies if need tech support/have questions?

 

[Hedges]

Midnight Classic is available 150, 200, 250V.
The have new Barcelona and Hawkes Bay for higher voltage and power.

MidNite Solar Alternative Energy Products: E-Panels to Inverters

MidNite Solar offers a large variety of alternative energy products from E-panels to charge controllers and inverters.

www.midnitesolar.com

Does your Aims inverter have any on-off control? If it won't do low-battery shutoff, some other device could tell it to.

Another approach, never let battery get too low (and BMS is last protection against over-charge.)
The inverter will have some no-load draw, plus you may have certain critical loads (like communications and security.)
You ought to get battery SoC status somewhere and use a contactor to shed all other loads. That way only non-critical loads get disconnected, and can automatically reconnect after sufficiently recharged.

I haven't used any of the batteries, but I'd think fewer 280 Ah would be preferable over more 100 Ah. Look also at maximum current draw, what imbalance could be tolerated including how many batteries can be offline with system still able to work.

Inspections - I think EG4 18kPV + 280 Ah PowerPro is a UL listed ESS. Maybe not all units have the required UL sticker. I didn't think the LifePower4 were, make sure of that.

I think the Midnight products will eventually have required listings, just don't know the timeframe.

Possibly a very small UL Recognized AGM battery would get you through inspections.

Midnight Rosie the Inverter looks promising, with people reporting good surge capability. If Midnight says that Rosie, Barcelona, and their batteries will play nice together that is something I'd consider if I was in your shoes. Possibly sticking with Aims for now, but with a path to pure Midnight system.

In my case I have pure SMA, except for charge controller from Outback and Midnight (not part of the systems I'm running right now.) I like the older SMA equipment. I'm seeing issues with firmware and repeated updates in the newer Sunny Boy Storage (with communications to BMS, that has to work with 3rd party products.) SMA is the only place I have experience dealing with support.

I think people have (usually) found CC to be very responsive (only one tale of issues I've read.) No first hand experience by me.

 

[seneysolar]

I contacted Midnite and they said new batteries will be available about mid-August but couldn't provide price or specs yet. However, I used their online sizing tool and it says my array power wattage is over what the Classic 250 can handle so I would still need a different brand controller.

You would run 2 of the 250 classics, parallel. Or as mentioned above if you want higher voltage strings, the Hawks Bay 90 or 120 is an option but they are pricey and you still need 2.
The Barcelona has 2 pv inputs, 585V max, tracked separately, 200A output, thatd be the best option if money is not an issue.

Yikes, have been learning that our current inverter may not have communications with batteries. I contact Ruixu re their batteries and they replied "This inverter is not suitable for our battery, in fact it is not suitable for any 16-string LFP battery. The inverter's Low Battery Trip is too low." So if not suitable for any 16-string LFP battery will it work with any EG4 batteries? If I understand correctly, the LifePower4 is 16-string? Not sure about their PowerPro (I'm having trouble understanding all the battery stuff). Our inverter manual says low battery trip point is 40 or 42 VDC for utility priority or 42 or 46 VDC for battery priority. Those are the only low battery trip point settings available. Would an option be to keep the inverter for running load from batteries but charge in winter through chargeverters and get matching brand batteries and controllers (ie EG4 as their controllers work with our panel specs)? Sorry a few questions here.

Low battery trip is not a feature you should plan on using. If the batteries ever got that low, the bms will turn off before the inverter.

In your case, the inverter would be set to AC priority and using a stand alone AGS. This way the AGS decides when to start based on battery voltage and the inverter charges anytime it has AC input. This would be a normal off grid hookup.

We have the 12KW AIMS inverter which works great but it has very minimal settings - select battery type and that's it, does the rest automatically. They don't have a setting for lithium so it must be "charge off". I can't find anything regarding lithium in the manual so I will have to call them. As you said, it seems like the simplest thing may be to buy same brand of everything.

You dont necessarily need a "lithium" setting, just the correct target voltage. The AGM 1 would be fine for generator charging because its going to be time limited, but it will depend on the battery. Just dont ever use an equalization or desulphation setting.

Summary of Above:
- Originally a number of people recommended to keep the AIMS inverter but I'm not sure which batteries it will work with - what do I look for in the battery and inverter the specs to know for sure? Is it the low battery trip point as referenced above?

Almost any battery will work. The inverter just sees voltage, it doesn't care where it came from. In most cases, battery coms are not required for operation. I see alot of folks on here that run the EG4 equipment open coms in lead acid mode.

For what its worth, Aims does offer a lithium battery option. Its just not well known. Something to check out.

- Signature Solar has inverters in stock,

no they are taking pre-orders

 

[SignatureSolarJess]

Signature Solar has inverters in stock, and Current Connected has EG4 wallmount batteries in stock (neither have both), and neither have the PowerPro4 6X rack in stock. Trying to find out when will be available, or if I should get the inverters from SS and wallmount batteries from CC and be done - or is that a bad idea to get from different companies if need tech support/have questions?

Hi! No vote here but just my two cents. I've been on the tech team and it has been difficult when a customer has many items from different companies as sometimes they get mixed up, or unit issues blend to other units and many things need to be addressed all the way through the system, causing the customer to have to contact multiple distributors for support for one problem, causing so much confusion for everyone involved. To be able to warranty and troubleshoot your system with minimal delays, I would personally recommend purchasing from one company if possible. It would streamline the process and give the techs/customer service associates a clear view of your system and equipment. If anything, for example, an extra cable needs to be sent out to you, there wouldn't be any question as to which company needs to source that.


For Signature Solar.. The stock is coming in.. We're almost to August, which should start clearing up a mass amount of backorders! Everything has been so much more popular than we could've imagined but these units are available for pre-order and the earlier you order, the earlier you'll get it. I've had customers wait to see if they became available elsewhere but realized that if they'd ordered when they originally wanted to buy, they would have it by now. Just check the estimated shipping dates on the websites, and if you have any questions or concerns for us here at Signature Solar, you're welcome to reach out to me directly at engagement@signaturesolar.com

 

[OffGridBC]

Thank you @Hedges and @seneysolar for your replies. I apologize for the delay (had company here until today).

I like your idea of keeping the inverter but using another device for charging the batteries, such as the EG-4 chargeverter. I don't intend to let the batteries get too low (we manually charge in winter before it gets to that point), but if I am away in winter it will have to be set to auto charge with the generator when low in which case the chargeverter will work great instead of charging with the inverter.

In my case I have pure SMA, except for charge controller from Outback and Midnight (not part of the systems I'm running right now.)

How do you like your Outback charge controller? I saw one for sale online and like the specs/features. It's not certified for here so may need to get the inspection first and then switch out the controllers after.

You would run 2 of the 250 classics, parallel. Or as mentioned above if you want higher voltage strings, the Hawks Bay 90 or 120 is an option but they are pricey and you still need 2.
The Barcelona has 2 pv inputs, 585V max, tracked separately, 200A output, thatd be the best option if money is not an issue.

I looked at running 2 of the 250 classics but Midnite's tool said it's just over the rated PV watts for each controller with our panel specs. Unfortunately Midnite's larger controllers are out of my budget range at this point. I would like to keep the inverter for now as it's new and just replace the controllers, but will likely swap out the inverter/controllers for a combo unit in future so don't want to break the bank on controllers right now. Looking into a few options.

You dont necessarily need a "lithium" setting, just the correct target voltage. The AGM 1 would be fine for generator charging because its going to be time limited, but it will depend on the battery. Just dont ever use an equalization or desulphation setting.
View attachment 230972

Almost any battery will work. The inverter just sees voltage, it doesn't care where it came from. In most cases, battery coms are not required for operation. I see alot of folks on here that run the EG4 equipment open coms in lead acid mode.

Great, thank you. I'm glad our current inverter can be used with lithium batteries.

For what its worth, Aims does offer a lithium battery option. Its just not well known. Something to check out.
View attachment 230985

Saw that but it is rated for about 1/2 as many cycles at 80% DoD than other batteries and higher cost.

 

[OffGridBC]

I haven't used any of the batteries, but I'd think fewer 280 Ah would be preferable over more 100 Ah. Look also at maximum current draw, what imbalance could be tolerated including how many batteries can be offline with system still able to work.

By "max current draw" is that "charging current" shown in the specs? The 280 Ah charging current is 200 amps max (recommended range: 60A - 160A). The 100 Ah charging current is 100 amps max (recommended 30-50A). I don't quite understand those numbers. Why is the recommended range substantially lower than the max charging current? Also wouldn't charging current be dependent on charge controller amps? For example, if charge controllers max charging current is 100 amps, then wouldn't that be too small for the 280 Ah battery? And why not set that to almost 100% for charging the 100 Ah batteries? Sorry for my ignorance. Trying to figure out best battery and charge controller combo to get and I don't quite understand how the amp specs of both work best together.

 

[wpns]

and just an hour old from EG4 a nice information tutorial and background info

She keeps saying that you _must_ keep your inverter loads within the output capacity of the CV, but it's really just the average load, no? If your loads exceed 5KW, then the inverter will draw additional power from the batteries, and the batteries will discharge, but when the load drops below the CV output, the batteries will go back to charging.

 

[seneysolar]

She keeps saying that you _must_ keep your inverter loads within the output capacity of the CV, but it's really just the average load, no? If your loads exceed 5KW, then the inverter will draw additional power from the batteries, and the batteries will discharge, but when the load drops below the CV output, the batteries will go back to charging.

Shhhh! They want to scare you into buying more chargeverters than you need

 

[Hedges]

By "max current draw" is that "charging current" shown in the specs? The 280 Ah charging current is 200 amps max (recommended range: 60A - 160A). The 100 Ah charging current is 100 amps max (recommended 30-50A). I don't quite understand those numbers. Why is the recommended range substantially lower than the max charging current?

Max current draw would be max discharge rate. Typically, discharge at 1C, 280A from a 280 Ah cell, is max continuous but some models may differ. Peak discharge rate for a few seconds might be 3C, 840A.

Max charging current is often spec'd at 0.5C, 140A for a 240A cell. The current it can take varies with temperature and SoC. Some data sheets say 1C or 280 Ah is OK below 80% SoC and at moderate temperature. 0.5C being OK from 0% to 100% SoC and a wider temperature range. At lower or higher temperature, further reduced current is needed to avoid damage or reduced life.

Tesla pre-heats batteries to they can accept a faster rate.

I'm probably going to configure a maximum rate of 0.15C, enough to fully charge battery in one day. I figure the only time faster would be desired for stationary ESS is if I only have a couple of hours before clouds roll in.

Why you cannot charge LiFePO4 below 0 degrees Celsius

I am not an expert either but my understanding is: The simple answer is just don't charge under 32*F The complicated answer is... its complicated, but still no.. ;) There are a number of variables to consider with low temperature charging (1) temperature (2) C-rate (3) SOC (4) degree of...

diysolarforum.com

Also wouldn't charging current be dependent on charge controller amps? For example, if charge controllers max charging current is 100 amps, then wouldn't that be too small for the 280 Ah battery?

Yes, SCC will determine max charge rate of your system. All that matters is charge rate not exceed what battery can accept without damage.

Unlike FLA which wants a minimum charge current to stir the electrolyte, lithium batteries are fine with a trickle charge.
So 100A charge rate or 5A charge rate is not a problem for 280 Ah LiFePO4

And why not set that to almost 100% for charging the 100 Ah batteries? Sorry for my ignorance. Trying to figure out best battery and charge controller combo to get and I don't quite understand how the amp specs of both work best together.

With separate components, maximum SCC output would go to battery if there are no loads, less if inverter is powering something.

With a hybrid/AIO, or some brands of SCC that communicate with a battery shunt, the SCC can adjust its output current to regulate battery charge rate while supplying additional power when inverter also draws current. Only something you need to consider if PV array is bigger than needed to deliver max allowed charge current.

 

[Hedges]

How do you like your Outback charge controller? I saw one for sale online and like the specs/features. It's not certified for here so may need to get the inspection first and then switch out the controllers after.

Seems fine.
I got the MX-60 years ago but didn't start using it until recently.

Easy to program with pushbuttons and LCD display. Note password printed in the manual it came with, needed to change settings. Should record inside the connection box for future use.
Supports 12V to 60V batteries, up to 60A output.

I'm using it to charge 12V and 48V AGM banks. Will look into settings for the LiFePO4 I just got after I attach BMS.

Manual that came with mine says 120V max PV, which is low for an array to charge 48V nominal battery.
Newer on-line manuals say 145V max under cold conditions when PV Voc is highest.
I think mine is the same but early manual kept it simple quoting PV panel nominal STC specs.

I've also bought a Midnight Classic 150 recently, together with the Sunny Island protocol adapter. Only good for earlier versions of SI firmware.

 

[Will Prowse]

My husband and I are fairly new to solar - we have had our system for about 18 months. We purchased everything through an off-grid company in Canada but have had consistent issues and in doing our own research realized the components they sold us don't work properly together. We have already purchased a replacement inverter and generator and have recently been told we need new controllers as well. We have lead acid batteries that we want to switch out with Lithium, so we’re basically redoing everything. I have been looking at EG4 products and would love advice on the best way to go so that we get a system that works well without having to continually buy more components. Thank you in advance for your feedback.

Solar Panels we have: 16 panels 450 watts each (7200 W total) - specs are attached. We are going to re-wire into two strings of 8 panels each.

Batteries: Looking to buy six 48v 100AH EG4-LifePower4 battery kit (30 kWh) - https://signaturesolar.com/eg4-life...enclosed-rack-with-door-wheels-busbar-covers/ OR six EG4 LL-S batteries

Current inverter: AIMS 12KW 120/240 split phase - https://www.aimscorp.net/product/12...split-phase-output-etl-listed-to-ul-1741-csa/


Options for the remaining components to purchase:

Option 1. Keep current inverter and get 2 EG4 charge controllers - https://signaturesolar.com/eg4-solar-charge-controller-mppt-500voc-100a-mppt100-48hv/ - each connected to a string of 8 panels

Option 2. Replace inverter and controllers with two EG4 6000XP Inverters (https://signaturesolar.com/eg4-6000xp-off-grid-inverter-split-phase/)

Options 3. Replace inverter and controllers with one EG4 12KPV inverter https://signaturesolar.com/eg4-12kp...in-one-hybrid-solar-inverter/?_hsmi=315974474


Questions that come to mind are:

1. Any feedback from others who have experience with EG4 products? I have seen some good and bad reviews regarding tech support.

2. Any significant difference between EG4-LifePower4 batteries vs EG4 LL-S batteries?

3. EG4 inverters/controllers say a combiner box is not required - is that true?

4. Option 1 would be the least cost and allow us to keep a newer inverter we have already paid for, but not sure how compatible EG4 products are with it or if better to get all same brand? Also, our current AIMS inverter idle consumption is 200 kWh which is a lot compared to EG4’s (50 kWh) and it doesn’t allow manual settings (you select type of battery and that’s it). Positives are they have good tech support and inverter seems to be working well.

5. We are in Canada and have to charge batteries with a generator almost daily in winter. We have a 14 KW generator. With option 1 the inverters max charge current is 125Amps (6000W). If we charge when the batteries get to about 20% then if my math is correct it would take 4 hrs to charge the batteries to full (24 kW / 6000 kWh charge = 4 hrs)? If we went with option 2 or 3 we can charge faster (8000kWh with EG4 12KPV or 2X Faster with two EG4 6000XP inverters - 12000kWh). That is appealing as it would save running the propane generator extra time.

6. I want to make sure the wiring we have buried in the ground will work with any of the above options as our system currently trips breakers. Our solar panels and backup generator are approx 75 to 100 feet from the house where the batteries and controllers/inverter are. The electrician used #6 wire from panels to controllers, and #4 wire to connect inverter to generator. If we put 8 panels in a string, according to the specs it will be 11.6 amps and 394.4 volts to each MPPT so I understand that should work with both the EG4 controllers or inverters, and should also be no problem with the 6 AWG wire - is that correct?

Also, I am not sure about the #4 wire connecting the inverter to generator. Is this equation correct? Generator sends 14KW to inverter (6000 Watts for battery charge and rest for domestic use) / 240 volts = 58.3 amps in which case #4 wire should be okay?

Then for wire from inverter to batteries: 6000 Watts / 48 volts = 125 amps. If upgrade inverter to two 6000 XP’s it would double to 250 amps? What wire size can handle that?

Currently when we start the generator manually it runs no problem and the inverter shuts it down when the batteries are charged, but when we set the generator to automatically come on when the batteries get low it will stay on for 10 to 20 minutes then quit, and keep starting and stopping, so we’re not sure if that’s an inverter issue, or #4 wire isn’t big enough to handle the amps (though seems implausible if it runs fine manually), or a loose connection with the auto start.


I’m not sure I am thinking of all the angles and options so am open to any advice and suggestions. I know this is a lot of info but I want to make sure to get components that will work together well and last a while this time.

Thank you kindly

I would do option 3. 12kpv is superior in my opinion. Then use the AIMS inverter to connect to the generator port and use that as well. Then total output would be crazy high. And you would have a sealed HF inverter and a heavy duty LF inverter. Best of both worlds.

If you are mounting them indoors or need 12kw output, the 6000xps would work great. But they are a bit loud indoors.

The aims LF inverter does work well, but I think you will like the features of the new eg4's. And you can use both.

 

[Will Prowse]

My husband and I are fairly new to solar - we have had our system for about 18 months. We purchased everything through an off-grid company in Canada but have had consistent issues and in doing our own research realized the components they sold us don't work properly together. We have already purchased a replacement inverter and generator and have recently been told we need new controllers as well. We have lead acid batteries that we want to switch out with Lithium, so we’re basically redoing everything. I have been looking at EG4 products and would love advice on the best way to go so that we get a system that works well without having to continually buy more components. Thank you in advance for your feedback.

Solar Panels we have: 16 panels 450 watts each (7200 W total) - specs are attached. We are going to re-wire into two strings of 8 panels each.

Batteries: Looking to buy six 48v 100AH EG4-LifePower4 battery kit (30 kWh) - https://signaturesolar.com/eg4-life...enclosed-rack-with-door-wheels-busbar-covers/ OR six EG4 LL-S batteries

Current inverter: AIMS 12KW 120/240 split phase - https://www.aimscorp.net/product/12...split-phase-output-etl-listed-to-ul-1741-csa/


Options for the remaining components to purchase:

Option 1. Keep current inverter and get 2 EG4 charge controllers - https://signaturesolar.com/eg4-solar-charge-controller-mppt-500voc-100a-mppt100-48hv/ - each connected to a string of 8 panels

Option 2. Replace inverter and controllers with two EG4 6000XP Inverters (https://signaturesolar.com/eg4-6000xp-off-grid-inverter-split-phase/)

Options 3. Replace inverter and controllers with one EG4 12KPV inverter https://signaturesolar.com/eg4-12kp...in-one-hybrid-solar-inverter/?_hsmi=315974474


Questions that come to mind are:

1. Any feedback from others who have experience with EG4 products? I have seen some good and bad reviews regarding tech support.

2. Any significant difference between EG4-LifePower4 batteries vs EG4 LL-S batteries?

3. EG4 inverters/controllers say a combiner box is not required - is that true?

4. Option 1 would be the least cost and allow us to keep a newer inverter we have already paid for, but not sure how compatible EG4 products are with it or if better to get all same brand? Also, our current AIMS inverter idle consumption is 200 kWh which is a lot compared to EG4’s (50 kWh) and it doesn’t allow manual settings (you select type of battery and that’s it). Positives are they have good tech support and inverter seems to be working well.

5. We are in Canada and have to charge batteries with a generator almost daily in winter. We have a 14 KW generator. With option 1 the inverters max charge current is 125Amps (6000W). If we charge when the batteries get to about 20% then if my math is correct it would take 4 hrs to charge the batteries to full (24 kW / 6000 kWh charge = 4 hrs)? If we went with option 2 or 3 we can charge faster (8000kWh with EG4 12KPV or 2X Faster with two EG4 6000XP inverters - 12000kWh). That is appealing as it would save running the propane generator extra time.

6. I want to make sure the wiring we have buried in the ground will work with any of the above options as our system currently trips breakers. Our solar panels and backup generator are approx 75 to 100 feet from the house where the batteries and controllers/inverter are. The electrician used #6 wire from panels to controllers, and #4 wire to connect inverter to generator. If we put 8 panels in a string, according to the specs it will be 11.6 amps and 394.4 volts to each MPPT so I understand that should work with both the EG4 controllers or inverters, and should also be no problem with the 6 AWG wire - is that correct?

Also, I am not sure about the #4 wire connecting the inverter to generator. Is this equation correct? Generator sends 14KW to inverter (6000 Watts for battery charge and rest for domestic use) / 240 volts = 58.3 amps in which case #4 wire should be okay?

Then for wire from inverter to batteries: 6000 Watts / 48 volts = 125 amps. If upgrade inverter to two 6000 XP’s it would double to 250 amps? What wire size can handle that?

Currently when we start the generator manually it runs no problem and the inverter shuts it down when the batteries are charged, but when we set the generator to automatically come on when the batteries get low it will stay on for 10 to 20 minutes then quit, and keep starting and stopping, so we’re not sure if that’s an inverter issue, or #4 wire isn’t big enough to handle the amps (though seems implausible if it runs fine manually), or a loose connection with the auto start.


I’m not sure I am thinking of all the angles and options so am open to any advice and suggestions. I know this is a lot of info but I want to make sure to get components that will work together well and last a while this time.

Thank you kindly

Aims idle consumption is 200W. 12kpv is 55W. That is a substantial difference that needs to be accounted for

 

[NC_hydro]

Unless EG4 is just the only thing you can afford I would stick with Midnight Solar or Victron inverter, especially with the recent price cuts from Victron. And if you really need to keep costs down I'd still skip EG4 and go with Growatt or some of these other cheap chinese AIO's. But IF you do go Eg4 don't buy it from Signature Solar, get it from Current Connected. Suggest reading through these threads and coming to your own conclusion: https://diysolarforum.com/threads/signature-solar-experience-bad-or-good.75508/

How can Current Connected improve?

No one ever gives us feedback on here...it's a blessing and a curse. I'm taking the chance to take feedback constructively before it becomes destructive like other vendors on this forum. Some things we are already working on: Hiring and training more technical support staff to spread the load...

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