Requesting advice on Axpert program setup

[stuvo]

My goal is to reduce my utility bill while getting maximum longevity from my battery bank.
On even a slightly cloudy days I have excess watts during peak solar hours. The batteries fully charge (charge led indicator goes solid,) but I usually go into bypass mode some time during the night.

Prior to installing the system, I used approximately 12kwh per day.  My load is usually around .5kw, often lower except when using the microwave or taking a shower, or vacuuming, or you get the idea. 

My main question is about the max utility charging current (program 11). I tried it at the default of 30A and it worked great. The system would go into bypass at night and charge up the batteries, and then switch back to batt mode. It might do this twice. Once in the evening and once in the early morning. This used quite a few (about 3kwh) on my utility meter though. I'm thinking that setting max utility charging to a lower value (10A) may leave me in bypass longer, but give the sun a chance to rise and start charging and reduce battery charge cycles.

Any feedback would be welcome.

Equipment:
SMKSOLAR Axpert MKS 5kVA 4000w 80A Inverter / Charger
8ea.  Rocket AGM Batteries 12v 100ah. Wired as 2 parallel strings of 4 batts (48v)
12ea. Seraphim 260w panels. Wired as 4 parallel strings of 3 panels (3.12kw)

PROGRAM:
1      Output source priority               SbU
2      Maximum charging current       50A
3      AC input voltage range              APL
5      Battery type                               AGM
11    Max Utility charging current       10A
12    Set V point back to util source    49v
13    Set V point back to batt mode    FUL or default 54V?
16    Charger source priority              CSO
31    Solar power balance                  SbE

 

 

[PaulF007]

Hello @stuvo

To make your batts last you will need to invest in a BMV battery monitor so that you kan see exactly what your batts is doing. Your setup seems to be ok for daytime consumption but 200ah is a little low for a 500w base load at night.
I for one would not even consider charging the batts with the grid as the losses is quite severe and as your goal is to save money it is sort of counterproductive. 

What I would recommend you look at is to only consume 10% - 20%  of the capacity of your batteries (Where the BMV monitor comes in) per night , this should give you the best time value for your batteries , then switch to grid. But do not charge the batts with the grid. They can stay on "idle" until the sun comes up and the panels start to charge them.Once the sun is good enough to support the house load switch back to solar and you should be able get the most out of your system. @Chris Hobson should be able to give you the correct settings to setup the system in that way.

 

 

[Chris Hobson]

Program 2 set to 20A (10% of your battery bank Ah rating.). You may be losing some solar production going to FUL perhaps 55V.

[stuvo]

10 minutes ago, Chris Hobson said:

Program 2 set to 20A (10% of your battery bank Ah rating.). You may be losing some solar production going to FUL perhaps 55V.

I was hoping you would chime in. I've scanned most of this forum while researching, and you seem like you know what you are doing. I'll make those changes and see what happens. 

Thanks

[SilverNodashi]

I got mine set to 2A, which just keeps the batteries topped with minimal eskom power

[Chris Hobson]

Welcome Have a look at the Axpert Settings I wrote a while back (in the download section). Once you understand you'll have the confidence to make the changes necessary.

The back to grid and back to solar setting are really something that needs to be set with your objectives in mind and the size of your battery bank plays a role. If you have a small bank then voltage changes due to either charging or discharging are rapid so one needs to ensure that one is not cycling between grid and solar the whole time. I like that your Program 16 is OSO. So come evening you use your batteries a bit and then go to grid. In the morning for a period you are still on grid and charging with solar. I would think that you should reach 55V by mid morning by which time you big array can  handle both charging and load. If you find that you are only at 54V mid morning then lower program 13 to 54V again. What you don't want is the system going to solar and moments later going back to grid because solar cannot carry the load. I am guessing you have a daytime base load of between 500 and 800W.

[stuvo]

11 minutes ago, SilverNodashi said:

 

I got mine set to 2A, which just keeps the batteries topped with minimal eskom power

 

I just made this adjustment based on what PaulF007 said. I don't want to loose efficiency both ways.

I'm now at this:

PROGRAM:
1      Output source priority               SbU
2      Maximum charging current       20A
3      AC input voltage range              APL
5      Battery type                               AGM
11    Max Utility charging current       2A
12    Set V point back to util source    49v
13    Set V point back to batt mode    55V
16    Charger source priority              CSO
31    Solar power balance                  SbE

I'll try this for awhile and see how it works. I want to use as little grid power as possible, but I live in a very rural part of the Philippines. We have black outs weekly. I want my batteries to be there for me when that happens and it is raining.

Thanks All for the input.

[PaulF007]

@stuvo 

15 hours ago, Chris Hobson said:

Welcome Have a look at the Axpert Settings I wrote a while back (in the download section). Once you understand you'll have the confidence to make the changes necessary.

I never saw that in the download section and must admit once you have read through it just about every thing will make sense in fact I printed and laminated it and is now right by the inverter for future reference! 

Thanks @Chris Hobson !!

[Chris Hobson]

 

1 hour ago, PaulF007 said:

....in fact I printed and laminated it and is now right by the inverter for future reference! 

Perhaps I should do the same. I use to have the program sequence at my fingertips but since I have not really made any changes to my system in 18 months I have forgotten it all. @Don and I got to talking cross purposes the other day because I thought AC charging was Program 3 when in fact it is Program 11.

[PaulF007]

2 hours ago, Chris Hobson said:

@Don and I got to talking cross purposes the other day because I thought AC charging was Program 3 when in fact it is Program 11.

I checked your manual yes it is 11 

[stuvo]

I would very much like to download the Axpert settings guide by @ChrisHobson , but I guess I need 15 posts first. Does this count as a post or do I need to create unnecessary new posts?

I don't know how to do that link think with the user names.

 

[Don]

Yes, that counts as a post. I know @Energy made some changes to the system regarding the uploading of files. It seems those same rules apply to downloading. 

To link to a user's name: Type @ and a space, then start to type the users name. It might start off with a few names. Keep going until you see the name you want and then select the name.

[Energy-Jason]

Hi Guys, 15 posts are needed. This is enforce for us to get to know everyone a bit. :>

Sincerely

Jason

[Don]

Agreed, no problem from my side.

[Gabriël]

i see i need 15 posts to get the axpert setup which don wrote - at present i only have two so this is number 3, 12 to go...

i have the 5kva model and had it installed.

the other stuff is:

4x sonic agm gel batteries [sorry i lack exact specs]

8x300watt pv panels renosol
 

today was my first attempt to start 'tuning' it and i already found some settings not to my liking - maybe the guys who supplied it overestimated my tech capabilities, but anyhow here is the rundown for some present settings:

1-sol

2-60a

3-apl

4-sds

5-agm

6-ltd

7-ttd

9-50hz

11-30a

12-46v

13-54v

16- cso

19-fep

23-bye

26-56.4v

27-54v

29-42v

the geyser [solar] and oven are on eskom. my electricity usage at night is minimal although i have enabled bypass in option 23 just in case.

my aim is obviously not to stress out the batteries and yet to use as little eskom as possible.

yours in Christ

gabriel

[Chris Hobson]

Welcome Gabriel

9 hours ago, gabriel said:

i have the 5kva model and had it installed.

the other stuff is:

4x sonic agm gel batteries [sorry i lack exact specs]

8x300watt pv panels renosol
 

today was my first attempt to start 'tuning' it and i already found some settings not to my liking - maybe the guys who supplied it overestimated my tech capabilities, but anyhow here is the rundown for some present settings:

1-sol Good  especially with your stated aim of not stressing your batteries out. Basically solar during the day Eskom at night.

2-60a Your batteries will never produce that amount of power Eskom will and it may be too high for you batteries - need battery specs

3-apl Good

4-sds Good

5-agm Rather have this set to USER so that you can set Bulk and Absorb voltages to suit your batteries

6-ltd Good

7-ttd Good

9-50hz Good

11-30a We need your battery specs suspect this is too high

12-46v Too low - 47 to 48V. With your state aim of not stressing your batteries maybe even 49V if you do not have heavy loads on your inverter. Heavy loads cause battery voltage to drop significantly and so battery voltage  might drop below 49V when if fact the batteries have hardly been discharged at all. Set first to 48V and then monitor.

13-54v Set to 55 or 56V

16- cso Only solar charging

19-fep My preference too

23-bye Good

26-56.4v Battery spec dependant

27-54v Battery spec dependant

29-42v This program is near useless. Get yourself a BMV 702 to monitor your batteries and switch using state of charge (SOC) rather than voltage. IN the mean time set to 46 or 47 V and switch off the alarm (program 18). Otherwise it will moan incessantly.

the geyser [solar] and oven are on eskom. my electricity usage at night is minimal although i have enabled bypass in option 23 just in case.

my aim is obviously not to stress out the batteries and yet to use as little eskom as possible.

yours in Christ

gabriel

 Send me your e-mail address in a personal message and I will send you a copy of Don's Axpert guide .

[Don]

10 hours ago, gabriel said:

4x sonic agm gel batteries [sorry i lack exact specs]

This is an important spec. Don't you have an invoice when you bought the. Post a pic of the batteries, someone might just recognize them.

2-60Aa is way to high for 4 batteries. You are not charging them, you are cooking them. Change this to 10A until we have the correct Ah rating of the batteries.

11-30A Same as above. Change to 10A

12-46 This is too low. Set it to 49V

29-42 This is too low. Change this to 46V

[Don]

@Chris Hobson. Sorry only after posting did I notice you already posted.

 

[Chris Hobson]

4 minutes ago, Don said:

This is an important spec. Don't you have an invoice when you bought the. Post a pic of the batteries, someone might just recognize them.

2-60Aa is way to high for 4 batteries. You are not charging them, you are cooking them. Change this to 10a until we have the correct Ah rating of the batteries.

11-30A Same as above. Change to 10A

12-46 This is too low. Set it to 49V

29-42 This is too low. Change this to 46V

3 minutes ago, Don said:

@Chris Hobson. sorry only after posting did I notice you already posted.

NP - At least our recommendations are the same. It would be embarrassing if we differed.

 

[Don]

I know, as I posted I saw your post. I was stressing out reading through your post and prayed I got it right, haha.

[Chris Hobson]

3 minutes ago, Don said:

I know, as I posted I saw your post. I was stressing out reading through your post and prayed I got it right, haha.

At least Gabriel knows what to do as he has it now from two sources

[Don]

Yes, I thought to leave the battery settings at AGM for now, at least we know they are AGM batteries, until we get accurate information about the batteries.

[Don]

11 hours ago, gabriel said:

i see i need 15 posts to get the axpert setup which don wrote

Correction Gabriel, @Chris Hobson is the one that explains the Axpert setting in detail, not me.

[Chris Hobson]

1 hour ago, Don said:

Correction Gabriel, @Chris Hobson is the one that explains the Axpert setting in detail, not me.

We can make it Don's and Chris's guide to the Axpert . I wrote it to help with the Axpert not to be the final say on Axpert setup. Anyone can make a contribution and it will be acknowledged. 

[Don]

@Chris Hobson, no, the guide was your initiative and your hard work, therefore you should take the credit for it. We can all contribute and debate settings. You can then from time to time make changes to the guide, should it be required.