Minimum number of batteries for Victron inverter

[Andy]

I’m slowly researching my system and would prefer not to put down money for 6 pylontech paired with a Victron MultiPlus 8000 just yet. The link https://www.victronenergy.com/live/batt ... ch_phantom suggests it needs 6 batteries at a minimum but I keep hearing about soft start functionality in the us3000c batteries. Would that mean I can reduce the number required to say 3?

[Stinsy]

The minimum number of batteries is 1.

However the batteries form a “stack” and the “master” reports to the inverter the allowable charge/discharge current. For the US2000 batteries this is 25A per battery. So you are restricted to 1200W per battery. You’d not be getting he most out of your very expensive inverter with 3 batteries and 3600W but if that is what you want to do, go ahead!

[Tinbum]

I’m slowly researching my system and would prefer not to put down money for 6 pylontech paired with a Victron MultiPlus 8000 just yet. The link https://www.victronenergy.com/live/batt ... ch_phantom suggests it needs 6 batteries at a minimum but I keep hearing about soft start functionality in the us3000c batteries. Would that mean I can reduce the number required to say 3?

A single us3000c battery isn't enough to soft start a single Sunny Island inverter, it takes 2 goes and the inverter doesn't always like that and has to have the capacitors totally discharged to restart.

[nowty]

I'd say 4 of them as a minimum and I would recommend fitting them as 2 x 2 in parallel as in the picture from the link you sent.

Recommended continuous charge / discharge rate is 37A per US3000 battery pack.

That 8000 Victron is similar in spec to my SMA 8.0 Sunny Island which has a max continuous discharge from its battery pack of 140A.

140A / 37A = 3.8 battery packs.

If your going to limit the max continuous output to say 110A / 120A, around 5kW after inefficiencies, you could get away with a single stack of 3.