Help or Advice

I have a Giv energy system. The system has 17 400 watt solar panels , a 5 kw hybrid inverter and 2 9.5 givenergy batteries. As the output to the grid max is governed by inverter I was told that my max output to my demand would be 5kw. This was what I wanted as my max demand was about 4.5 ( swimming pool system) . I charge my batteries in the winter 100 % on economy 7 supply and in the summer I vary the charge time weather depending - all looked great. BUT then came the shock if I need the battery then the max output allowed to is 2.6 kw and the rest comes from the grid which is counter productive. I am not technical in terms of electronics etc just want a system to support my needs. I had thought of splitting the system in 2 but givenergy as I understand do not support this approach.
It is a dc system has anybody any ideas or even a givenergy supplier who could help. I like the system and the support I have found to be good but what am I missing in order to meet my requirement and allow max battery usage.

Trumper Other than going for two unoupled inverters (which I think you've already explored), upgrading to a gen-3 (or gen-2 ?) inverter would increase the battery limit from 2.6kW to 3.6kW - not a completel solution, but does get you closer. And if you hang onto the gen-1, then maybe when the EMS does come out, and it supports mixed generations of inverters, you could run the two inverters together.

Trumper Hello there, as you have found the headline ‘5kW inverter’ refers to the maximum DC that can be converted to AC, unfortunately not the same as the max battery charge or discharge rate which as DD says is 2.6kW on a Gen 1 and 3.6 on a Gen 2 or 3 inverter.

You can have multiple hybrid inverters working together to share the workload and whilst it is not a recommended solution by GivEnergy, it is supported and it does work - I have just such a setup and max discharge is around 5.6kW (I get 2.9kW from the inverter with the 9.5 battery and about 2.7 from the one with a 5.2). Max charge is about 4.8kW (2x 2.4).

The only real issue with this setup is that since the inverters are independent and not aware of each other, they can tend to cross charge, one senses a load and discharges, the other sensing excess power starts charging. For me this is quite gentle, about 100-200kW, for others (I think the Gen 3’s respond faster) it can be up to full rate. You can fix this by setting the inverters to pause charge, but need to clear this when you do want to charge them!
The EMS will in theory at some point in the future resolve this issue, but I wouldn’t hold you breath as to when its launched. I believe the focus also is on multiple AC coupled inverters in the first release, not hybrid’s.

Other issue, of less importance for me, is that the load and power generation figures in the portal and app are screwed. But if you can live with this it’s not a major inconvenience.

Alternative would be to get an all in one. Has a 6kW discharge limit and they are now starting to offer multiple parallel units. Would mean junking your existing inverter and batteries though.

Sidebar-
If your inverter capacity is 5kW and the panels have a higher capacity than that (6.8kWp based on 17 x 400W) then you are also going to experience clipping unless there is space in your batteries to store the excess energy.
I know some members limit their charge rate to spread their export more through the day in order to manage that, exporting earlier whilst their battery is not full to ensure that they still have battery space available when the sun is at its peak. It may be that some of your panels are shaded or north facing and you will never actually see that 6.8kWp, but on Octopus Outgoing Fixed that could be up to £0.27/hr going to waste on really sunny days.
Of course we don't know what realistic limit your DNO would allow on a G99 certificate, and your maximum charge limit sounds like it is sufficient to soak up any possible excess of you do manage the charge state.
System automation may be worth playing with to handle that for you. Several users seem very happy with cloud based services if you don't want to set up and manage something yourself.

Small silver lining WRT discharge, members have reported that the maximum discharge limit increased to 3kW on supported Gen 1 inverters and batteries under the yet to be released fast response firmware when they were testing it. So that may close the delta slightly for you if your kit will support that when the firmware is eventually released.

pwdst 2.89kw on mine with the new software