Hi,

After adding 3 new pylontech H48074 batteries to my rack (6 batteries same brand and nr) the charging stops at 50%. After this it goed from pv to grid. Before it was charging to 100% everyday. How can i resolve this? Thanks

 

best regards,

 

Q

Here you can see what i’m talking about.

5 hours ago, Quenton said:

Hi,

After adding 3 new pylontech H48074 batteries to my rack (6 batteries same brand and nr) the charging stops at 50%. After this it goed from pv to grid. Before it was charging to 100% everyday. How can i resolve this? Thanks

 

best regards,

 

Q

Hi, Are the batteries connected via a comms cable to the inverter? What is the inverter saying is the maximum battery capacity? If the max battery capacity is incorrect in the inverter you should be able to adjust it to what it should be (600Ah I am guessing). Another tip I can give you is to ensure your maximum battery charge current is set to no more than 150 amps. This is to protect the batteries from damage.

Edited October 28, 20241 yr by HendrikBigChief

13 hours ago, HendrikBigChief said:

Hi, Are the batteries connected via a comms cable to the inverter? What is the inverter saying is the maximum battery capacity? If the max battery capacity is incorrect in the inverter you should be able to adjust it to what it should be (600Ah I am guessing). Another tip I can give you is to ensure your maximum battery charge current is set to no more than 150 amps. This is to protect the batteries from damage.

Hi HendrikBigChief thank you for the help. The batteries are indeed connected via a comms calble the the inverter. I cannot find aything abou the battery in the app 'im using (SolisCloud). What i can see is that the battery voltage is 450.3 V (total 9 pieces) and SOH is 100. Battery status is: normal. The max battery charge current is set to 100 amps.

Just going by the datasheet for the H48074 battery, if you've got 9 in series, you'd be looking at a Battery System Charge Upper-Voltage of n*54 = 486V. Lower Discharge Limit n*43.5V=391.5V. And the battery charge/discharge current is best kept to 37A for normal operation. Battery capacity 666Ah.

[Edit. Correction: Battery Capacity is still 74Ah at (9x48V). Thanks @Scorp007].

Are these in line with the values you're reading from the BMS? Do you have a possibility to set these values manually through your inverter in a "Voltage mode" to see whether it operates as expected?

Edited October 29, 20241 yr by GreenFields

42 minutes ago, GreenFields said:

Just going by the datasheet for the H48074 battery, if you've got 9 in series, you'd be looking at a Battery System Charge Upper-Voltage of n*54 = 486V. Lower Discharge Limit n*43.5V=391.5V. And the battery charge/discharge current is best kept to 37A for normal operation. Battery capacity 666Ah.

Are these in line with the values you're reading from the BMS? Do you have a possibility to set these values manually through your inverter in a "Voltage mode" to see whether it operates as expected?

Hi Greenfields this is what i get to see. I will try to acquire the rest of the info (capacity) and if possible set the values and see how it works then. Thanks

Think you need to alter this.

10 minutes ago, Tinbum said:

Think you need to alter this.

Hi Tinbum, it’s 14.8 now. I don’t know why it changes the value when i make a screenshot

Did you balance the batteries before fitting?

As they are in series as soon as a single battery gets to 100% SOC it will stop any current flowing through the others. (Unless Pylontech have a way of overcoming this internally).

Edited October 28, 20241 yr by Tinbum

On 2024/10/28 at 11:30 PM, Quenton said:

Hi Tinbum, it’s 14.8 now. I don’t know why it changes the value when i make a screenshot

Ah, that's because the BMS is limiting it. In your first shot the battery is at 52% which is when you say it reaches its max SOC.

I'm pretty sure your problem is because you fitted the new batteries when they were at 52% SOC (or perhaps say 30% and SOC is average), as supplied by Pylontech and the older ones were 100% SOC ie fully charged. (Edit probably the opposite way round as the manual says they come at 100% soc unless otherwise requested by supplier.)

Edited October 30, 20241 yr by Tinbum

7 hours ago, Quenton said:

Hi Greenfields this is what i get to see. I will try to acquire the rest of the info (capacity) and if possible set the values and see how it works then. Thanks

Ok, I realize now your batteries are in series, not parallel. So your problem is that you need a battery balancer. If you don't have a battery balancer, your batteries will drift apart over time and that would explain why you cannot charge them past 50%.

On 2024/10/29 at 5:20 AM, HendrikBigChief said:

Ok, I realize now your batteries are in series, not parallel. So your problem is that you need a battery balancer. If you don't have a battery balancer, your batteries will drift apart over time and that would explain why you cannot charge them past 50%.

Pylontech will have factored that into the design so you won't need a balancer.

I'm sure it's because the new ones were fitted at a vastly different soc as I said above. They probably will balance, as shown by the 1A setting but it will take weeks / months.

Edit The new batteries need removing then the old batteries discharging to the same soc as the new ones and then the new ones adding in again. Their may be other ways depending on what you have available.

Edited October 30, 20241 yr by Tinbum

Just had a quick glance at the manual and it shows a warning here and says pretty well what I thought.

and

 

 

 

It also explains here how the system works. A reinstall as a first install system would have sorted it but making sure that other conditions above are met first to ensure no high surge currents that could damage things. this is for multiple strings though.

A full read of the manual is always a good thing.

Edited October 30, 20241 yr by Tinbum

@Quenton Any update?