Battery only storage - Worth it?

[Oldman22]

On the Fogstar literature it mentions something about the fact that those battery banks do not require an inverter to work. That's puzzling... I wonder how would the AC/DC/AC conversion happen?
Surely it needs an inverter!

I assume a standard inverter would be required, without the need for hybrid? This should cost less too.

It is crucial to note however, that inverter integration is not required for our server rack batteries to function.
Pretty sure that means the battery can mimic a battery type that is catered for in an inverter as Fogstar wont be on the list as its a brand new product. In my case I tell the inverter that they are Pylontech batteries.

 

[binky]

I assume a standard inverter would be required, without the need for hybrid? This should cost less too.

Standard inverters only do solar, it's either hybrid, or there are one or two battery only inverters. Look for AC coupled battery inverter./ system

 

[bladerunnerpv]

With all these battery systems one thing to bear in mind is the weight of them.

A few examples after some web searches:

One system with 13.5kWh storage has a footprint of ~600x300mm and weighs around 175kg, incl inverter

4x Pylon 3000C's is ~14kWh and ~125kg

PYLON FORCE-L2 LOW VOLTAGE SYSTEM 14.2KWH ~175kg, incl. base, in one tower

PYLON FORCE-H2 14.2kWh ~155kg in one tower, footprint ~450x300mm, 96V modules

PYLON FORCE-H1 24.8kWh ~259kg in one tower, footprint ~600x380mm, 48V modules but system can run in the 100s of volts

By instinct I'd be concerned about nearly 260kg in a loft on that size footprint!

 

[johnb2713]

On the Fogstar literature it mentions something about the fact that those battery banks do not require an inverter to work. That's puzzling... I wonder how would the AC/DC/AC conversion happen?
Surely it needs an inverter!

I think it may be this what youve seen "inverter integration is not required for our server rack batteries to function" it does still need an inverter to supply your energy, it just doesnt need comms between the battery and inverter.

I assume a standard inverter would be required, without the need for hybrid? This should cost less too.

Some people refer to inverters with a battery charger built in as hybrid.

There are inverters designed for battery storage with no solar, search for 'AC Coupled'. Victron Multiplus II and Solaredge are two that I know of.

 

[Creakyride]

I think it may be this what youve seen "inverter integration is not required for our server rack batteries to function" it does still need an inverter to supply your energy, it just doesnt need comms between the battery and inverter.

Some people refer to inverters with a battery charger built in as hybrid.

There are inverters designed for battery storage with no solar, search for 'AC Coupled'. Victron Multiplus II and Solaredge are two that I know of.

Thank you. I'll have a look at these.
Trying to source my local electrician. I have used one for a small job but not sure he want to get involved in these kind of install.

 

[Creakyride]

What size fuse is needed from the mains for a 15KWh battery and a adequate inverter? 32A?

The mains has a 100A fuse.
The 7KW car charger box has 32A.

 

[johnb2713]

What size fuse is needed from the mains for a 15KWh battery and a adequate inverter? 32A?

The inverter you need to go for 5 or 6kW as a minimum, any smaller the kettle and the toaster would cause import from the grid. My 5kW Multiplus II has a 50A MCB in it's own dis-board. It charges the batteries at 3.5kW and has supported the grid (supplied my house) with just under 9kW, way over it's design rating but it was quite happy for several minutes before the temperatures rose.

The mains has a 100A fuse.
The 7KW car charger box has 32A.

Yep, same as my setup

 

[matt.bram]

See post #3

Sorry I missed this. Thanks for explaining, very interesting. I'll be using this in my calcs.