My second battery has four lights on, 5th flickering, first and last one light on, 2nd flickering, indicating 19% SOC

Master is 3.5, other two 2.4

Can it be set that all three drain equally? 

This should work:

1. Charge each battery individually to 100%.  You will probably need to disconnect the others.

2. Reconnect, making sure that the 3.5 is master (Link port 0 unused)

 

 

Also make sure that one wire to the battery comes from the top of the stack, and the other from the bottom.

4 hours ago, MartinKoch said:

My second battery has four lights on, 5th flickering, first and last one light on, 2nd flickering, indicating 19% SOC

I cannot speak of Pylontech specifically, but I had this experience with a client of mine who had (newly installed) Coslight batteries. They were imbalanced for the first few weeks. After maybe 3 or 4 weeks of cycling they eventually “found” each other and the lights eventually synchronized. 

There is a video on boobtube showing how it “introduce” new Pylontech  batteries. 

They'll take a couple of weeks to get in synch with each other.

 

Thanks for all the feedback, only had the main 3.5 for about four weeks, will monitor, they all do charge to 100%

I have 2 US3000s, one 3 weeks old and the other about 2 months. The newer one doesn't charge to 100% at all, whether it's the master or slave or the only battery on the inverter. It just stops at some point. First day it was 82% then slowly crept up to about 90 at about 1-2% per cycle, then at about 3-4% per cycle to a best of 99%. But now it's gone back down to 90% and is fairly stable.

It's consistently a similar % below the other one. This not only costs me capacity on top but also prevents me cycling the bank as low as I would like. Is this the normal pattern for batteries finding each other, or do I have an issue?

49 minutes ago, Vassen said:

Have you tried fully charging each battery separately before joining them together and are you wiring them with positive on 1 battery and negative on the other. I have read that newest battery should also be the master. 

How are you charging them? Using CAN or RS485. 
With my US3000, I notice that it gets stuck on 88% soc for some time and then very quickly goes to 100%. 

Tried separately, and as master and slave, new one won't go to 100% irrespective of the rest of the system. Initially the new one was made master but I've tried all permutations to try to fix this. I think it's slave at the moment though. I'll revert.

Cabling is correct. Batteries in parallel, positive to one, negative to the other.

CAN to the Axpert, Console to the Pi for ICC using the official cable. Lights on battery and ICC agree on SOC.

Voltages set at 53.2 but only the old battery gets there. New one stops in the mid 51s

Will take them to full and hold them to see if it goes up. I'm a little under panelled so usually only get full late afternoon for an hour tops before it starts drifting doen again

 

20 minutes ago, Hagu13 said:

Voltages set at 53.2 

I would say that this is too high for normal charging of the Pylons. Recommended values here in the forum are 52.5V for Bulk and 51.8V for Float

2 hours ago, Hagu13 said:

It's consistently a similar % below the other one.

A minor difference in SOC is normal in my experience. Here a screenshot of my pack just now. Notice how the voltage is basically the same for all batteries, but the SOC differs. However, they all get to full at one point. When I added my last battery, it would also at the beginning sometimes not get 100%. Usually I would say to give it a few more weeks and it should balance out

36 minutes ago, Hagu13 said:

New one stops in the mid 51s

Is this also the case if you connect it by itself? And does the voltage increase over time or always remains at the same 51.x V?

1 hour ago, Vassen said:

With my US3000, I notice that it gets stuck on 88% soc for some time and then very quickly goes to 100%. 

This apparently is normal behavior for the Pylons. Plonkster wrote a detailed explanation for the why somewhere here in the forum

 

I've tried a few voltages from 52.5 to 53.2. I was initially lower but raised it to try to help it fill up. No effect. 

Voltage and amps move around for a few minutes after full but then don't change. Same if it's alone. But I've never parked it full and on charger for more than about an hour so I'll try that.

I find it odd that it improved from 82 to 99% and then went back to 88. Think I'll hold them overnight tonight instead of cycling them and see what happens

ok so I have some feedback

Yesterday I made the newer battery the master and charged the bank to full. With the old battery at 100% and new battery at 92% the current dropped to zero and there was just the occasional pulse going in. Temperatures went up a little and SOC slowly drifted to 94% on the low one. So similar to before although the 2% drift was new and heartening. Fairly big delta between highest and lowest cells- maybe 0.25v.

Powered the system down and took the old battery away. Let the new one drift down a few % and then charged again. Similarly went to 94% and stopped, but the pulsing every few minutes continued. After a few hours of checking every 15 minutes or so SOC suddenly went to 99% At this point I started watching cell voltages and saw that they were converging slowly. The higher ones were more responsive to upwards spikes but the low ones resting voltage was drifting upwards 

An hour or so later SOC showed 100% but still 0.67AH from maximum, with delta between cells just under 0.2v.

By bedtime I had AH at max and 0.06v between highest and lowest cells.

Left it overnight. By morning the cell deltas are within 0.04v. And temperature has dropped to normal so it doesn't look like it's doing much balancing work. Reconnected the other battery as slave and set it back to solar. It's only going to shallow cycle on the kettle and dishwasher today but I'll pull it down overnight and see if they stay close or diverge.

 

Hi everyone, 

I inherited a system when I bought a house 4 months ago. 3 x Pylontech US3000A and 2 x Axpert 5kVAs. Originally the system had no controller, so the inverters were controlling the batteries on voltage only. I have recently bought Solar Assistant and can now see what's happening with the batteries. 

The master battery at the top of the stack is charging/discharging at around 10% to 20% the rate of the others. Eventually the whole stack is getting to 100% SOC, but when discharging, the master only gets down to ±70% while the other 2 are close to 21% and the system switches back to grid charging.

From Solar Assistant I can see that the master battery has around 20% of the number of cycles that the other 2 have (±180 vs ±960). I can also see that it's serial number has a slightly different format, starting with PPTB2XXXX while the others are PPTAHXXXXX7 and PPTAHXXXXX8 respectively (i.e. sequentially directly after each other).

Is there a chance that the batteries have different firmware which is causing the different charging rates? Any other thoughts or suggestions on how to remedy this? 

Many thanks!

Firmware won't affect your rate of charge/discharge. I suspect the batteries are not the same age. There's not much you can do in this instance, the voltage curve of the PPTB battery is different from that of the PPTA batteries. It could be that there is a fault on the PPTB battery causing this, or just that they have different cells.

I would try installing the latest firmware on each ,it may help a little bit to sync up with each other. I also just added a new battery to my stack and since i updated the firmware it seems they are better balanced so it might be worth a try .

4 hours ago, Nexuss said:

I would try installing the latest firmware on each ,it may help a little bit to sync up with each other. I also just added a new battery to my stack and since i updated the firmware it seems they are better balanced so it might be worth a try .

Thanks Nexuss,

How do I go about this? Does is not void warranty, etc.? 

2 hours ago, Davy777 said:

Thanks Nexuss,

How do I go about this? Does is not void warranty, etc.? 

I wouldn't do that if I were you. You inherited the batteries, meaning if you brick one, during the update, you have no warranty to fall on. Try simple things first and if you must then upgrade. I would leave with the batteries as they are, atleast you can still use them. Rather than having one or more batteries dead because of firmware upgrade failure. Try balancing them, there is a thread here on how to balance the Pylon batteries. If that doesn't work, then make peace with it. I would also change the master battery, try making a different battery a master and see what happens. 70% and 21% is a huge difference, I doubt Firmware upgrade will fix that. get hold of Pylontech support, Jef is the go to guy, very helpful and he seems to know his stuff 

I have just added a second hand US2000 plus battery on my stack that has a different FW from my battery bank. All I did was just to switch everything off, then powered switched ON, only the batteries and allowed them to have the same amount of LEDs ON then connected and powered up my system. It took few hours but seems to have worked. The old battery is always behind with one LED when charging but eventually gets to 100% like the others 

9 hours ago, P1000 said:

Firmware won't affect your rate of charge/discharge. I suspect the batteries are not the same age. There's not much you can do in this instance, the voltage curve of the PPTB battery is different from that of the PPTA batteries. It could be that there is a fault on the PPTB battery causing this, or just that they have different cells.

Thanks P1000, 

They were procured at the same time. I'll double check the manufacturing date on the nameplate tomorrow, but I'm think that they are quite similar, so I'm not sure that it's date related.

Will update tomorrow though

10 hours ago, Davy777 said:

 

With the 2nd and 3d batteries at 900-odd cycles and the 1st one less than 200, certainly a significant age difference between them, I'd think the two older ones are probably approaching their 3d birthday, whereas the younger one is yet to see its 1st birthday, I'd imagine...

4 hours ago, hoohloc said:

Try balancing them, there is a thread here on how to balance the Pylon batteries.

To me it seems that the batteries are balanced. All of them are at 41.8V. So I don't think this will solve the issue

13 hours ago, Davy777 said:

Any other thoughts or suggestions on how to remedy this?

Do you regularly charge cycle them? To me it seems that them BMS of the one Pylon is off. Because at the same voltage it is reporting a way different SOC. My Pylons are usually also all at the same voltage and I get small differences in SOC, but less than 5% - nothing like your case. Maybe charging to 100% and letting the individual cells balance can help get the BMS 'back to normal'?

Or something with that Pylon is faulty

On 2023/02/24 at 7:17 PM, Davy777 said:

Thanks P1000, 

They were procured at the same time. I'll double check the manufacturing date on the nameplate tomorrow, but I'm think that they are quite similar, so I'm not sure that it's date related.

Will update tomorrow though

So the mystery deepens!

I switched out packs 1 and 2. Same behaviour, pack 2 (previously pack 1) is still charging/discharging at around 20% of the other 2 packs. 

BUT...something else I didn't pick up before. The current pack 2 (the one operating at 20%) has a different serial number on its sticker than what is shown on the software. On the sticker, the serial number follows the same format as the other 2 packs (PPTAHXXXXX10) while on Solar Assistant it's still showing me the different format serial (PPTB2XXXX7).

Can you post a photo of how they are connected? It must be positive of first battery and negative of last battery to inverter. (Or other way around). Thinking that maybe the inverter is connected to the first battery and the others just paralleled from the first.

Other way around - both connected to the last battery I suspect...

 

 

 

 

All batteries are operating in parallel, but I manged to get hold of Pylontech support and after a bit of back and forth, it seems that one of the current sensors on pack 2 is out of calibration. They suggested that I can reset it myself, but I need access to a variable DC charger:

"If you still want to calibrate the current sensor, please use a DC charger, set 53.2V and 10A to charge the battery.

Connect the battery in the batteryview, select 'option' then 'control panel', and check index 11 'current sensor reset'. When the current on the DC charger is displayed 10A, click the button and the problem should be fixed."

 

I'm new to the Somerset West area. Could anyone assist me with a recommendation for where I could get hold of a DC charger (to buy or to use) as described above? 

@Davy777 Ever solved this problem ? I have a similar issue with 1 out of 8 batteries in a pack.

Hi @Jaxone

So it turns out that the PMU/CMU was damaged by an overvoltage of 54.2V, even though my inverter charge voltage was set to 53.2V. Segen Solar ended up replacing the PM/CMU for around R2k and now it's working fine. Pylontech subsequently recommended that I set the charge voltage to 52.5V, which I have done.

Another thing I found helped was to swap some of the battery packs around in the stack. A mixture of different internal impedances and high impedance battery lead connections could also affect the relative discharge rates of the packs.

Hope that helps!