My 44kW vertical and bifacial set in Finland.

44kW of PV
making 204kWh in Feb.
Sunrise/set at 63 north, you have 7hours (8:30 - 4:40)
44kW x 7hrs x Eff = 204kWh,
Your system is running 66% efficient in Feb. with stationary panels - well. at least during a sunny day.


That is because N.America exported our winter this year!
(we are calling this "The year without a winter" - it has been raining and we have nearly zero snow on the ground)
62 north. Antlerhead is 63 north. That's why he has antlers and I don't.
 
44kW of PV
making 204kWh in Feb.
Sunrise/set at 63 north, you have 7hours (8:30 - 4:40)
44kW x 7hrs x Eff = 204kWh,
Your system is running 66% efficient in Feb. with stationary panels - well. at least during a sunny day.

Sunrise / sunset doesn't really equate sun hours though.
 
Welcome!

Look at post #253 and some following posts. You are not the only one asking about this...

Summer consumption is much less, but total is 40-45MWh/year. This winter has been exceptionally cold and snowy.
Thanks. I took a look very interesting , Ithought they were joking when they mentioned your swimming pool 😉😉
 
Had a bad cell in my 10kWh rack battery and manufacturer sent replacement cells to fix it. Was a bit worried as I have been reading here how hard these pre-assembled batteries are to work with if anything goes wrong. At least this one was super easy to do.

10kWh rack batt.jpg

Opened the lid.
lid open.jpg

BMS
BMS.jpg

Changed defective cells.
changing cells.jpg

Installed Neey 4A smart balancer
Neey 4A smart balancer.jpg

Need to put it in one piece again. Don't know when I have time to do that and can't be sure if I even remember how to anymore. Plan is to drill a hole for Neey cables in the casing so I can connect/disconnect balancer box when ever I want. This way I need only one balancer, but I can use it with many batts when I just install wirings to them.
 
Had a bad cell in my 10kWh rack battery and manufacturer sent replacement cells to fix it. Was a bit worried as I have been reading here how hard these pre-assembled batteries are to work with if anything goes wrong. At least this one was super easy to do.

View attachment 197405

Opened the lid.
View attachment 197407

BMS
View attachment 197410

Changed defective cells.
View attachment 197414

Installed Neey 4A smart balancer
View attachment 197413

Need to put it in one piece again. Don't know when I have time to do that and can't be sure if I even remember how to anymore. Plan is to drill a hole for Neey cables in the casing so I can connect/disconnect balancer box when ever I want. This way I need only one balancer, but I can use it with many batts when I just install wirings to them.
Who was the manufacturer? Good to not have laser welded cells in this case
 
Had a bad cell in my 10kWh rack battery and manufacturer sent replacement cells to fix it. Was a bit worried as I have been reading here how hard these pre-assembled batteries are to work with if anything goes wrong. At least this one was super easy to do.

View attachment 197405

Opened the lid.
View attachment 197407

BMS
View attachment 197410

Changed defective cells.
View attachment 197414

Installed Neey 4A smart balancer
View attachment 197413

Need to put it in one piece again. Don't know when I have time to do that and can't be sure if I even remember how to anymore. Plan is to drill a hole for Neey cables in the casing so I can connect/disconnect balancer box when ever I want. This way I need only one balancer, but I can use it with many batts when I just install wirings to them.

Rule I learned a long time ago: Take a picture (or five) before disassembling. Heck, do that when I unhook my PC from all of its cables these days.
 
Why does that battery bar configuration not look right to me?
It has 2 cells in parallel.

Used to be a more common practice when cells were smaller. Using 2P16S and 100Ah cells would increase capacity to 200Ah.

It allows for paralleling weak cells with stronger cells to cover up the weakness if the builder is unscrupulous.
 
Who was the manufacturer? Good to not have laser welded cells in this case
I was prepared for laser welds, but fortunately there was none. Can't tell manufacturer as I have promised my friend not to tell anyone as these batteries are his business. He sold these to me without any profit for ~175e/kWh almost year ago. Now I can buy new ones under 130e/kWh if I decided to get more.
 
Why does that battery bar configuration not look right to me?
2P16S, but also blade style cells with terminals on the opposite ends. Not side by side like in regular prismatic cell.

It has 2 cells in parallel.

Used to be a more common practice when cells were smaller. Using 2P16S and 100Ah cells would increase capacity to 200Ah.

It allows for paralleling weak cells with stronger cells to cover up the weakness if the builder is unscrupulous.
Due to price range I didn't have high expectations. Was surprised that they send replacement cells free of charge and even offered free installation wherever I want. They sure have no clue how expensive that would be here... But I wanted to do this myself, even if there would be laser welded busbars as I wanted to learn how to do it. At the same time I could learn how to connect a balancer.

Now, I really can't call myself DIY battery builder because of this, but now I'm pretty sure I could do it if needed.
 
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Got it in one piece again!

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20240224_135706.jpg

20240224_144117.jpg

It has to be easy because even I managed to do it.

This is the top battery in the rack so it is ok to have wires coming from the top. For other ones I'll have to make it through back wall (or front wall) which is just as easy. Now I need to lift it back to the rack and do a top balance which is easy and fast with Neey smart balancer. Even this 4A capable unit is more than enough with 200Ah batt. New cell was only @3,1V while other 15 cells were @3,29V. It took about 20 hours to get them within 2mV (so ~80Ah transferred to the new cell) with the 4A balancer. Now that they are balanced at the horizontal part of the charge curve, they are going to be widely apart when charged close to 3,5V. But even they are far away voltage wise, there's only a few Ah between them. To make top balance this way even 1A active balancer would be just fine.

Now it got me thinking about balancing my 625Ah(C5) forklift battery too. Neey isn't lead acid compatible, but how would it know? It is 24S compatible so it should work just fine if I can set the "sleep voltage" low enough for FLA (~2,2V). I need to do an equalization cycle first and then determine if "top balance" is even needed.
 
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Got only 10kWh yesterday. Very dark and rainy day (rain, not snow). Best so far has been last Sunday with 228kWh produced. PVWatts is predicting 2,7MWh this month and it looked fine after one week with ~1,5MWh produced. Now I'm at ~2MWh and according to forecast I'm not going to get much more. Day is almost 10 hours long already so maybe those 2kWh daily yields like back in December are already gone.
 
Well, seems like we're in for a completely gray week now...
Heavy fog all day today and I mean pea soup heavy, almost ridiculous. 43kWh still. Can't be sad. But yes, really gloomy weather for next few days. Next week looks much better, but I'm sure they will find more rain drop images for their charts until then...
 
Hey! I just came here from another thread where you mentioned you had sealed the backs of the bifacial panels you had cracked. How have they held up? I am planning to do the same: clear sealant and laminate film
 
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