It's Working!!! Sol-Ark 15K, 33.52kW with 67 Panels AC+DC PV, 60kWh SOK Batteries - Photo Diary

[OffGridForGood]

I thought about that. I like to keep things simple if possible. I was going to wait and see what the spread is after the batteries top balance for a month. With eight batteries the spread was only about 5%. Right now the spread is pretty extreme around 22%. If it doesn't come into balance within 5-7% I'll probably split them into two sets of six. We'll see what happens.

And post what you find out after running for awhile!
I also found another trick - swapping two packs: the packs are all slightly different IR and from the balance I saw one always a bit high and another always a bit low - so swapped them in the rack - now they run very near perfect balance with the rest of the packs.

 

[HighTechLab]

And post what you find out after running for awhile!
I also found another trick - swapping two packs: the packs are all slightly different IR and from the balance I saw one always a bit high and another always a bit low - so swapped them in the rack - now they run very near perfect balance with the rest of the packs.

This is the most thoughtful post that I've seen in a VERY long time. It shows you really understand what's going on within. Major kudos to you for deeply considering the real world scenarios and working them to be favorable.

 

[Ryushin]

So one of the new batteries is being stubborn is only charging to 54.7 volts and it says it's 100% charged and stops charging at that point. I'm currently doing closed loop charging with the Sol-Ark 15K. I've seen that closed loop tops out at 56.3 and I'm fine with that, and actually rather it not charge all the way to the top.

So I'm thinking of running open loop for a few days to hopefully get everything balanced. According to the Current Connected web site and an email I received when I got my first batteries, I should set absorption at 57.6, float at 55.2 and EQ to 57.6. @HighTechLab what are your thoughts?

Edit: I went ahead and changed the Sol-Ark 15K to open loop and manually set the charging to 57.6. Interesting that Solar Assistant shows the Sol-Ark in AGM battery mode.

 

[HighTechLab]

If you can't wait, the fastest way to get a battery to balance, is to watch the battery and note the system voltage when the first cell hits approx 3.61 - 3.62v. Set the system to keep the voltage constant at that voltage and leave it for a day or two...you have to make sure the battery didn't trigger OVP though as that will slow down balancing. I did this on a battery last week with a chargeverter, 56.2v overnight and the cells all lined up enough to where I could bump the voltage up to 57 and let it sit another night. Dead nuts on from there.

Frankly though, it wouldn't hurt anything if you just run the system and let the BMSs do their thing...but I get that not everyone has the same confidence as I do.

In case you aren't already, I would use one of the new batteries as the master battery versus one of the older ones.

 

[Ryushin]

If you can't wait, the fastest way to get a battery to balance, is to watch the battery and note the system voltage when the first cell hits approx 3.61 - 3.62v. Set the system to keep the voltage constant at that voltage and leave it for a day or two...you have to make sure the battery didn't trigger OVP though as that will slow down balancing. I did this on a battery last week with a chargeverter, 56.2v overnight and the cells all lined up enough to where I could bump the voltage up to 57 and let it sit another night. Dead nuts on from there.

Frankly though, it wouldn't hurt anything if you just run the system and let the BMSs do their thing...but I get that not everyone has the same confidence as I do.

In case you aren't already, I would use one of the new batteries as the master battery versus one of the older ones.

Oh, good to know. I can be patient for a few weeks while the BMS do it's job.. It seems all four of the new batteries won't get to the proper voltage yet. Do you think I should keep running open loop at 57.6V or is going back to closed loop at 56.3V fine? I would think it would be fine to go back to closed loop since the other three batteries I added last year synced up fine.

Just glad to have enough battery power now to get through the nights. Thanks @HighTechLab for everything that you do. I appreciate it.

 

[KevinC_63559]

In case you aren't already, I would use one of the new batteries as the master battery versus one of the older ones.

Dexter? My new SOKs are about 7 months newer than my “old” SOKs. Should I do the same?

Thanks for this tidbit, its not something I was thinking about.

 

[Ryushin]

In case you aren't already, I would use one of the new batteries as the master battery versus one of the older ones.

Other then balancing sooner, is there another reason for using the newer batteries as the master rather the ones from 15 months ago? I did not change the order and just added the other four batteries as 9-12.

 

[LydMekk]

Open loop aka voltage control is quite okay. No issues here after 3 years with a mix of 2 types of batteries with same cell count.
I do 3.55V per cell and then 3.45 float.

 

[HRTKD]

Howdy @Ryushin, I stopped in to take a look at your photos to see if I could spot where about in the "The Rock" you were located. I'm up the road in Highlands Ranch.

Good looking setup!

 

[Ryushin]

Howdy @Ryushin, I stopped in to take a look at your photos to see if I could spot where about in the "The Rock" you were located. I'm up the road in Highlands Ranch.

Good looking setup!

Hey @HRTKD, thanks for the kudos. I was thinking with the dual Excel power poles and the street sign in the pictures I could be found. Maybe I'll have to scrub some of the details in the diary photos.

From some of the PMs I've gotten, the photos have been helping quite a few people get their systems installed. The parts list also goes a long way.

I'm very pleased with the system and it's been rock solid. Very happy with the support from Sol-Ark which I need in the beginning to get it to interoperate with the Growatt inverters.

Now if I can just stop it from snowing on the panels.

 

[HRTKD]

Now if I can just stop it from snowing on the panels.

Good luck with that. I'm still dialing in the system in my RV which is at the storage lot near Louviers. I've had to clear the snow from the panels on the roof twice.

 

[Ryushin]

Well a couple of days ago the last of the four batteries balanced out. So it took about two weeks for three batteries to get into sync and the last one was stubborn and took another week to finally get with the program.

When the Sol-Ark 15K drains the batteries down to 20% which is the floor level I have set, there is about 18% spread between the highest and lowest charged batteries. I'll have to watch it more to see if I want to split it into two packs of six. It's nice and simple now. Adding equal length 4/0 welding/battery cable and bus bars to split it just to reduce the spread to about half might not be worth it.

So I guess I'll just let it run for a few months and see where it settles down then make my decision then.

 

[Brucey]

Well a couple of days ago the last of the four batteries balanced out. So it took about two weeks for three batteries to get into sync and the last one was stubborn and took another week to finally get with the program.

When the Sol-Ark 15K drains the batteries down to 20% which is the floor level I have set, there is about 18% spread between the highest and lowest charged batteries. I'll have to watch it more to see if I want to split it into two packs of six. It's nice and simple now. Adding equal length 4/0 welding/battery cable and bus bars to split it just to reduce the spread to about half might not be worth it.

So I guess I'll just let it run for a few months and see where it settles down then make my decision then.

So some are at 11% and some are at 29%? With twelve in series it definitely isn't ideal.

 

[Ryushin]

So some are at 11% and some are at 29%? With twelve in series it definitely isn't ideal.

Well it really comes out to be about 16% to 34%. I've attached a image at the current 48% state of charge right now. But yea, I get that it is not ideal. It hasn't gotten down to 20% yet since all batteries have gotten into balance so I can't say it's 18% for sure.

Edit: Odd, the attached image was not showing up. Used a different method:

 

[houseofancients]

Well it really comes out to be about 16% to 34%. I've attached a image at the current 48% state of charge right now. But yea, I get that it is not ideal. It hasn't gotten down to 20% yet since all batteries have gotten into balance so I can't say it's 18% for sure.

Edit: Odd, the attached image was not showing up. Used a different method:

Give it time, they are still balancing themselves out

 

[Ryushin]

Give it time, they are still balancing themselves out

Oh really, I didn't know that. I thought once they all matched the same voltage when charged to 100% they were balanced. I'll give it another month and see what it looks like then.

 

[shinyballs]

What's the length and wire awg you use to connect solar panels to charge controller?