Differences between two offgrid solutions

Q&A and troubleshooting
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1

Hallo,
I’m planning to build an offgrid system (no grid connection!) and have to choose between two device-combinations. The system is to charge an electric car without grid, single phase, 10A and 235V. There is a big LiFe battery 48V / 30 kWh and 6 kWp solarpanels (at two strings).

  1. Victron MPPT RS 450/100 + Victron Inverter Smart VA 48/5000
    I believe that the inverter can handle peak loads better because of the toroidal transformer. Right? And there ist a eco-mode, which consumes only 3W at standby.

  2. Victron Multi RS Solar 48/6000/100
    Only one device, cheaper than (1), smaller, lighter. But lower “max. PV operational input current” (13A instead of 16A). No eco-mode (consumes always 20W) and I don’t know how it handles peak loads without heavy transformer.

Can you help me to decide? Thanks!
Lars

2

So you are expecting a 2300 to 2500 watt load? (10A x 230v)

This is more than capable. The 13A refers to the panels chosen. So what are the panel spec of what is available to you?

It can do a peak of 9500 watts if you have decent battery voltages.

If you are fully offgrid then look at the inverter RS. It is cheaper than the multi rs.

3

Yes.

String 1:

a) 8 Panels with 450 Wp, Voc 38.80V, Isc 14,35A, Vmpp: 32,35V, Impp 13,51A (touches the 13A operational input)
or b) 7 panels with 450 Wp, Voc 52.6V, Isc 10.7A, Vmpp 44.6V, Impp 10.1A (only 7 panels because of 450V)

String 2 has only 7 modules anyway, so there is no problem with 450V.

Overall the MPPT RS 450/100 would be better with less restrictions.

The Inverter RS 48/6000 supports only 1 solar string, not 2, and I need 2. I would have to AC-couple the second string (and buy a additional inverter for that).

4

If you have machines with heavy peak loads like welding equipment, go for MP2.

If you have man shades and/or different angels consider adding micro grid inverters to an MPPT.

One hybrid Multi RS 6000 would be great from installation point of view. Everything is included including DC switches.

The Multi RS cannot be paralleled, if you need additional inverter capacity. You can only add PV inverters for more AC or RS 450 for more DC chargers.

The RS do not hum like the MP2.

5

Well, a Multiplus-2 48/5000 would be much cheaper than a pure inverter like the “Inverter Smart VA 48/5000”. Onlineprices 555€ instead of 866€. Both use copper toroidal transformer and should perform similar at peak loads (?). The MP2 offers more functions (which I don’t need) and is cheaper at the same performance class (?).

In an other community somebody wrote, he tried to charge his car with an cheap inverter, and the car stopped charging in the first few seconds because it thought the supply was too weak. Then he bought a inverter smart VA 48/3000 and it worked. Perhaps some cars act like peak loads while starting the charge.

The noise of MP2 or of “inverter VA 48/5000” does not matter, it will be outside the house in a shed.

For argumentation to the network operator it’s easier, if the device is not able to connect to the network at all than if it were able and I just don’t connect it.

So I will choose combination (1) of the first post. Thanks for the answers and new food for thought!
Lars

6

You can add more charge controllers to the system.

Has the same peak power as the Multi RS.
Although in aes search mode has the 2-3w standby that you want

7

Oh, yes, I forgot this. Then the RS 48/6000 is an interesting alternative.

Thank you again! I have to read much more…