Pylontech Batteries

[DavB275]

Thanks everyone. Appreciate all the input.

Yes I'm running 24v system. Had to import these from Italy - none in UK.

Tinbums explanation of the 28.4v is what I believed it to be.

Re. the cable connections - I originally had them connected to top and bottom units of the stack, but it seemed it was the top and bottom units that were giving high voltage alarms first each time. Tried the current config. to see if it made any difference. Effectively I now have + & - to two stacks of three.

[Tinbum]

The thing is with the pylontech their are so many different versions and the documentation doesn't always keep up. The 24v have different communication to the inverter depending on age and I have seen different charge voltages in the pylon documentation.

Some docs show 28.2 - 28.5v and others 28.2 -28.8v

[Stinsy]

The thing is with the pylontech their are so many different versions and the documentation doesn't always keep up. The 24v have different communication to the inverter depending on age and I have seen different charge voltages in the pylon documentation.

Some docs show 28.2 - 28.5v and others 28.2 -28.8v

Either way 28.4V is good to go!

[Joeboy]

You were not balanced as you know, please redo your cables too. 1 in 6 out. Keep balancing. Batteries are one of the few representations of Not Just plug & play although appearing to be. All the best, cheers!

[DavB275]

You were not balanced as you know, please redo your cables too. 1 in 6 out. Keep balancing. Batteries are one of the few representations of Not Just plug & play although appearing to be. All the best, cheers!

Thanks Joeboy. Yes, I intend to re-balance again at some point. Have already re-configured the cables. Now have 1 in, 3 out, and 4 in, 6 out. Both ins and outs feeding from common bus bars, as I read somewhere that it's not good to run a stack of more than 4 from a single set of the Pylontech long cables. Trust this will work ok. All advice is welcome. Cheers. Dave

[Joeboy]

You were not balanced as you know, please redo your cables too. 1 in 6 out. Keep balancing. Batteries are one of the few representations of Not Just plug & play although appearing to be. All the best, cheers!

Thanks Joeboy. Yes, I intend to re-balance again at some point. Have already re-configured the cables. Now have 1 in, 3 out, and 4 in, 6 out. Both ins and outs feeding from common bus bars, as I read somewhere that it's not good to run a stack of more than 4 from a single set of the Pylontech long cables. Trust this will work ok. All advice is welcome. Cheers. Dave

No worries, glad to help. Had not heard about 4+ being an issue? I run 6 US2000's and have not had any problems or even felt heat in the cables. Good to know though.

[Tinbum]

The cables are limited to about 120A so for more than 4 units you should run 2 sets of cables from the pack to the inverter. (I guess it really depends on the max current your going to pull or charge).

[nowty]

@DavB275, sorry for not replying to my question about your max charge voltage as I missed it, but I think its all been correctly covered by the reply's from Tinbum and Joeboy.

I first thought 28.4v, thats high for a 24v system !, but as the 48v Pylontechs have 15 cells, the 24v ones must have 8 so when I cross checked on my own tables, 100% on an 8 cell Pylontech would be about 28.3v.

Others have found some low cell alarms when they are first installed, it seems that sometimes, especially if you are using the whole capacity you need to do a few cycles for all the cells to balance up.

For your reference I knocked up this table for an 8 cell Pylontech battery for voltage vs SOC


Cells are damaged if you go above 3.7v per cell so 29.6v with the pack, or below 2.65v per cell or 21.2v with the pack.