Proper process for balancing two Dyness batteries

[denmendez65]

Do you ever see 29V on your batteries?

Its sitting there now as we speak. The weird behavior i have seen is the inverter switching between float and absorption voltage throughout the day. Batteries are pulling 2A at the moment but the voltage is at 28.8V. It will drop for 5 minutes and jump again. I never concerned myself with it to be honest.

 

[leon.davibe]

I would assume I have inherited this bug also since I have a Voltronic clone. Never had issues, my charging voltage is set to 29V (58 if I was 48V system) and float is 27.6V(55.2). Maybe I dont see this issue because my settings are "high"?

yea i have also set my float settings high to avoid this bug

 

[leon.davibe]

Its sitting there now as we speak. The weird behavior i have seen is the inverter switching between float and absorption voltage throughout the day. Batteries are pulling 2A at the moment but the voltage is at 28.8V. It will drop for 5 minutes and jump again. I never concerned myself with it to be honest.

yea if the batteries charge full no need to worry about it if not then scratch

sometimes scratching where it doesn't itch is a bad thing

 

[wingnut771]

Its sitting there now as we speak. The weird behavior i have seen is the inverter switching between float and absorption voltage throughout the day. Batteries are pulling 2A at the moment but the voltage is at 28.8V. It will drop for 5 minutes and jump again. I never concerned myself with it to be honest.

Yeah this is normal I think. The bug was it would bulk at the float voltage or something like that.

 

[leon.davibe]

Yeah this is normal I think. The bug was it would bulk at the float voltage or something like that.

yea i think if it spend more than x time at float voltage it would assume the battery is full

but yea lithium with its flat voltage curve throws it a ball it does not know what to do with

setting the float high avoids it as it can't easily sit at high voltage without being full
but you don't want to keep it that high float

not really bugging me at the moment with system size
but yea will have to get a new way of dealing with it once i fixed and fitted all the 2nd hand crap i bought

 

[wingnut771]

yea i think if it spend more than x time at float voltage it would assume the battery is full

but yea lithium with its flat voltage curve throws it a ball it does not know what to do with

setting the float high avoids it as it can't easily sit at high voltage without being full
but you don't want to keep it that high float

not really bugging me at the moment with system size
but yea will have to get a new way of dealing with it once i fixed and fitted all the 2nd hand crap i bought

So not a bug really then as it works fine with LA, its just how its programmed like the mecer trolley inverter.

 

[wingnut771]

..
but yea will have to get a new way of dealing with it once i fixed and fitted all the 2nd hand crap i bought

oror

 

[leon.davibe]

View attachment 1861974orView attachment 1861975orView attachment 1861976

Got
3000wp
5kw inverter
And 2 batteries 5kwh and 3.8kwh capacity tested good
just bad bms's

For 7k

And another 5kwh batyery for i think 1.5k

Have not ordered bms's and fittings to fit all this crap

Super glad all the batteries tested 100% capacity

 

[wingnut771]

Got
3000wp
5kw inverter
And 2 batteries 5kwh and 3.8kwh capacity tested good
just bad bms's

For 7k

And another 5kwh batyery for i think 1.5k

Have not ordered bms's and fittings to fit all this crap

Super glad all the batteries tested 100% capacity

You were talking about your float problem.

I would just live with it with the kit you got for that price.

Have you replaced your faulty cell?

 

[leon.davibe]

You were talking about your float problem.

I would just live with it with the kit you got for that price.

Have you replaced your faulty cell?

No not yet
Kept posponing

Will fix these batts
And do a swop out not to lose capacity

And then ican be relaxed and do it without a rush

Realky crap at getting to back burner stuff

Edit : and the accute gout attacks hasn't helped, if only i was taking the booze equivelant to match the fall out it it would make sense but nothing not a drop, genetic lottery crap

 

[wingnut771]

No not yet
Kept posponing

Will fix these batts
And do a swop out not to lose capacity

And then ican be relaxed and do it without a rush

Realky crap at getting to back burner stuff

How will you do it with welded terminals?

 

[leon.davibe]

How will you do it with welded terminals?

The shoto has bag cells with a soldered wire from on cell to the next

So i'm gonna cut the wire as it goes into the bad cell and crimp on a lug

Or so i am contemplating now

 

[wingnut771]

The shoto has bag cells with a soldered wire from on cell to the next

So i'm gonna cut the wire as it goes into the bad cell and crimp on a lug

Or so i am contemplating now

Ah pouch cells, I was picturing prismatic.

 

[SauRoNZA]

15% then

Turns out at 15% 1 light for SOC is still on so who knows.

Come to think of it should only turn off once that is gone.

80-100% - 5 lights.
60-80% - 4 lights.
40-60 - 3 lights
20-20 - 2 lights
0-20 - 1 light.

 

[wingnut771]

Turns out at 15% 1 light for SOC is still on so who knows.

Okay one light then

 

[Hanno Labuschagne]

So update after maintaining 100% SoC for 24 hours...The newer (left) battery still discharges significantly faster than the older (right) one, when looking at the light indicators at least.

Gap widens over time.

5 to 4 lights drop: Happens at 80% overall SoC. Older battery only drops to 4 at 77% overall SoC.

4 to 3 drop: Happens at 63% overall SoC. Older battery only drops to 3 lights at 54% overall SoC.

3 to 2 drop: Happens at 45% overall SoC. Older battery only drops to 2 at some point after 34% overall.

2 to 1 drop: Happens at 28% overall SoC. Older battery does not drop to one light all the way down to 11% overall SoC.

Haven't gotten around to testing voltages yet, but at this point I think my installer needs to come and test themselves.

It is worth noting that I previously had another issue with the batteries not taking all the available charge that I detailed in another thread. This only started happening after we added the second battery:

Thread 'Strange issue with solar power production'

May 29, 2025

Hi everyone

I noticed a strange problem with our solar power system's production in Pretoria today (29 May 2025). The specs are as follows:

• 6 x 545W JA Solar panels
• 5kW Deye hybrid inverter
• 2 x 5.12kWh Dyness DL5.0C batteries

Early on in the day, I noticed that solar production was picking up slower than in the past few days despite clear skies and similar irradiance.

By 11:35, just as our 3kW geyser turned on, the peak generation was only at 2.06kW, despite the battery still being far from full. Yesterday at the same time it was 2.68kW. See images below for comparison...

• Hanno Labuschagne
• deye deye inverter dyness dyness batteries self-generation solar power solar production
• Replies: 64
• Forum: Eskom and Electricity: Load Shedding

That issue (largely) went away after I changed my minimum SoC from 15% to 20%.

I am a bit worried about what is happening with the newer battery when the overall SoC is under 20%

There seems to be a nearly 10% difference between the two...it is getting awfully close to the absolute minimum 10% SoC each day.

Also had a rare sudden 4% SoC drop around 20% but figured that may just have been an issue with logger.

 

[wingnut771]

So update after maintaining 100% SoC for 24 hours...The newer (left) battery still discharges significantly faster than the older (right) one, when looking at the light indicators at least.

Gap widens over time.

5 to 4 lights drop: Happens at 80% overall SoC. Older battery only drops to 4 at 77% overall SoC.

4 to 3 drop: Happens at 63% overall SoC. Older battery only drops to 3 lights at 54% overall SoC.

3 to 2 drop: Happens at 45% overall SoC. Older battery only drops to 2 at some point after 34% overall.

2 to 1 drop: Happens at 28% overall SoC. Older battery does not drop to one light all the way down to 11% overall SoC.

Haven't gotten around to testing voltages yet, but at this point I think my installer needs to come and test themselves.

It is worth noting that I previously had another issue with the batteries not taking all the available charge that I detailed in another thread. This only started happening after we added the second battery:

Thread 'Strange issue with solar power production'

May 29, 2025

Hi everyone

I noticed a strange problem with our solar power system's production in Pretoria today (29 May 2025). The specs are as follows:

• 6 x 545W JA Solar panels
• 5kW Deye hybrid inverter
• 2 x 5.12kWh Dyness DL5.0C batteries

Early on in the day, I noticed that solar production was picking up slower than in the past few days despite clear skies and similar irradiance.

By 11:35, just as our 3kW geyser turned on, the peak generation was only at 2.06kW, despite the battery still being far from full. Yesterday at the same time it was 2.68kW. See images below for comparison...

• Hanno Labuschagne
• deye deye inverter dyness dyness batteries self-generation solar power solar production
• Replies: 64
• Forum: Eskom and Electricity: Load Shedding

That issue (largely) went away after I changed my minimum SoC from 15% to 20%.

I am a bit worried about what is happening with the newer battery when the overall SoC is under 20%

There seems to be a nearly 10% difference between the two...it is getting awfully close to the absolute minimum 10% SoC each day.

Also had a rare sudden 4% SoC drop around 20% but figured that may just have been an issue with logger.

How many kWh did you get out of them?

Can you show us the AGM settings?

 

[Hanno Labuschagne]

How many kWh did you get out of them?

Can you show us the AGM settings?

8.90kWh from the 89% depleted. 89% of 10.24kWh is about 9.11kWh, but a 2.35% difference is probably not a sign of cell failure? Please excuse my ignorance on the AGM front, this is all I could find on battery voltage and was taken at 15% SoC.

 

[wingnut771]

8.90kWh from the 89% depleted. 89% of 10.24kWh is about 9.11kWh, but a 2.35% difference is probably not a sign of cell failure? Please excuse my ignorance on the AGM front, this is all I could find on battery voltage and was taken at 15% SoC.

Sounds fine to me. Not the pic I was looking for which was the charge voltage but it shows it in your pic anyway of 56.5V which is fine for 100% charge. I think the new battery has a lower resistance, nothing can be done because it is what it is and not an issue. You're getting ~9kWh at the end of the day.

 

[Hanno Labuschagne]

Sounds fine to me. Not the pic I was looking for which was the charge voltage but it shows it in your pic anyway of 56.5V which is fine for 100% charge. I think the new battery has a lower resistance, nothing can be done because it is what it is and not an issue. You're getting ~9kWh at the end of the day.

Thanks, appreciate the feedback. Just to be clear: Would there not be cases where the newer battery's SoC drops below its minimum rated depth-of-discharge if I set the minimum overall charge across the entire bank to 20%?

Or would the BMS stop drawing from the newer battery entirely once it reaches its 10% minimum and use only the older battery?