Battery expansion question - Solis / Pylontech

Archer Hack · 14-04-2023 08:39AM #1

Hi there,

I currently have a 5kw solis inverter connected to a single 3.6kwhr pylontech battery.

I am looking to add 2x 4.8kwhr pylontech batteries to this setup.

inverter has a max charge/discharge of 100A and cables are rated for 100A continuous with a 125A breaker between battery pack and inverter.

Am i correct in thinking that since the inverter has a max charge/discharge of 100A then the existing cables and fuse will suffice even if the batteries themselves have the potential to discharge at higher amps?

So the upgrade would be to add the 2 extra packs as per diagram (assuming space in cabinet), set one of the new packs to be the master and possibly some adjustments of inverter settings?

I might get installer/electrician to do this, but just want to be armed with facts for what needs to be done in advance.

Thanks for any input!

SD_DRACULA · 14-04-2023 09:45AM

The one thing you don't need to worry about is that the 100a charge/discharge for the Solis is false advertising.

It can only sustain 100a for 15 mins then it derates itself to 70a so your cables will never see 100a for more than 15 mins

If the cables are at least 25mm2 then you are good.

Archer Hack · 14-04-2023 09:58AM

https://www.boards.ie/discussion/comment/120476236#Comment_120476236

Thanks for that info, did not know that limit was there. Useful to know for overnight/smart rate charging expectations. Not sure of the mm2 but thanks will check that out also.

slave1 · 14-04-2023 11:01AM

Are you sure 3XPylontech can output at that high a rate (I don't know the answer but thought they were quite low in their output level)

SD_DRACULA · 14-04-2023 12:29PM

Seems to be 2.4kw normal if they are the US5000 battery

unkel · 15-04-2023 03:25PM

https://www.boards.ie/discussion/comment/120476236#Comment_120476236

Even 16mm2 is good for 100A for such a short time, but would have to be replaced should you upgrade

Coltrane · 19-04-2023 07:07PM

https://www.boards.ie/discussion/2058292327/battery-expansion-question-solis-pylontech

Your other new 5000 will need to be connected to the (new) master before your existing battery.

The 5000s weigh 40kg so you may not wish to put them in the same stack as your existing, in which case you'll need longer cables than the standard (short) cables supplied by Pylontech to make the connection between the two stacks.

Battery expansion question - Solis / Pylontech

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