diy solar

diy solar

Very new to solar but started purchasing items, not sure of the final specs of the whole system.

Middle bank was 53.28, Top bank was at 53.97.
Since the soc was similar with just slightly higher voltage I did not expect to many amps. I did connect using two wires with 30 amp fuses just incase.
What were the measure amps? Max I recorded was 22.9, dropping to 6.13 in about 8 minutes.
 

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Already down into the 1 amp range, let them sit overnight and start testing tomorrow.
 

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Doing better than I thought just letting them balance not using the batrium.
 

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Yesterday I brought the inverter online and configured it for 20 amps and it charged till about 55.80. Even though both were top balanced the lower bank had sat for about two weeks while I did the top bank. During the charging the top bank was around 3amps the bottom was 11 amps. By time it was near 55.80 it was 2.8 amps bottom .9 amps top. But 17, 29-32 are slightly lower.
 

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They are getting closer in voltage today, going to get a few sponges and jumper cables for number 17 hope he gets the message to get in line with the others.

update 2nd pic.
 

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Took a while but they are very close.
 

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I was curious to see how they would settle after the sun went down.
How I got them very close to each other:
- Set Float for 3.4 per cell
- Set Batriums for 1.68amps bypass at 3.4, lowered the amps since they were in bypass for longer than normal.
- Left Heltech connected
- With both the inverter and charge controller set for 3.4v float never went over 1.9amps
- Bank 17 / 20 where the lowest 3.6v+ so I used my smallest charger that put out 2amps to bring them up to 3.4.


All banks now checked directly show 3.4/3.39
Amps measured from bank 1 middle and bank 2 are now equal.
 

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Doing load testing this is one mini-split, and the whole house ac. With the inverter and charge controller set to 80 amps the battery draw dropped to roughly -7 amps, we have thunderstorms today.

The negative 59+ was when they were set for 20 amp on both.

With both banks working together the battery sag was nothing compared to a single bank. Based on amp draw the bottom bank was slightly higher but they were coming down together.
 

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They are doing very well, amps have been between negative -20 to 38 since 7:45 and they are staying very close.
Whole house has not kicked on yet so that will definitely expose any imbalances if any.
 

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They are doing very well, amps have been between negative -20 to 38 since 7:45 and they are staying very close.
Whole house has not kicked on yet so that will definitely expose any imbalances if any.
Are you using an active balancer still? I thought I saw one in an early photo.

After I watched this video it solidified my view that if my top balance was good then I did not need a balancer given LifePo4 chemistry and behavior when discharging (in short there will be imbalances as cells start to reach the bottom of the curve).

 
Are you using an active balancer still? I thought I saw one in an early photo.

After I watched this video it solidified my view that if my top balance was good then I did not need a balancer given LifePo4 chemistry and behavior when discharging (in short there will be imbalances as cells start to reach the bottom of the curve).
I still have them connected, but I think the float being set at roughly 53.74 will fix cell deviations I saw earlier and may no longer be needed. It's only been two days but I will keep updating on how well the are doing.
 
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Cloudy with some intermittent sun vs sun with no clouds

Have rougly 22-40 amp load today as well, 20 amps more than the cloudy day.

Batteries charged at 3:10 / Batteries completed at 12:14
Still have 35 more panels to wire up to charge controllers.

Also there is a delta between what growatt reports and my batrium shunt, what is shown per the growatt is much lower. I would trust the shunt more and it can be as much as 1100w difference.
 

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If they continue like this I will be very happy, the last part of connecting the two 4p16s banks kept me worrying.
 

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Had some nice weather today and got about 90% of the panels up. I did have the supports spaced out to far and fix them. It's not easy, the last row I'm going to have to slide them down from the top, just to steep for ladders.
 

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My new settings:
Charge to 54.00
float at 53.80
m8 set to bypass at 3.39
Heltech on

So far they are performing great considering these are not matched and mixed lots.
 

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Since the price was not too expensive and the hardware I had supported it I wanted to try out solar assistant. Setup and installation was very easy. I will provide a review and updates as I test the software.

Update:
I forgot to post the one caveat: For anyone with growatt this is currently read only and its waiting on an update to allow editing.
 

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They are doing very well so far been out pulling wires for the panels.
 

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Graphs have started updating: Total PC production was over 12kw for today, I switch over to solar and it was showing 9kw on the growatt server.
 

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Doing late night load testing to see how both banks react to long load via the main ac unit running. Inverter temps are doing well also.
Doubling the ac/heating side capacity really makes a difference in the sag voltage. What is interesting is the slight differences measure via the cables connecting the two banks but they are doing very well so far. I thought I had a screen of the loads but did not get one, the load was between 78-91 amps

Update can show some from solar assistant.
 

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So far I like the solar assistant more than the growatt server, both the inverter and charger are pushing the same amps throughout the day, so the real pv input should be double.
I would like to see: 12h, and °F, I looked through the settings earlier but did not see adjustments for this.

For loads we have the mini split running, lights, fan, dishwasher and still 50amps positive, from 36 500w panels. Hopefully in the next week
will add another 15 more panels to this side of the loads.
 

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