Does my battery really charge during a power cut?

We have a GivEnergy Gen 3 Hybrid Inverter and a Gen 2 9.5kWh battery, and it has an EPS setup where 2 of the mains rings (downstairs sockets and lights) run through the battery, so we can use it during a power cut.

We had a power cut just now and I saw 2 things I wasn't expecting:

1) The mobile app continued to report that the panels were feeding power to the house and the battery. My installer had told me this wouldn't happen because the inverter needs a grid connection to run. Is my mobile app telling me lies?

2) The backup EPS worked but my computer still fell over at the switchover point. I guess the switch over is not fast enough. Is that normal or can I do anything about that?

Thanks

YES

On grid failure your inverter will disconnect from the grid so that you do not back feed battery power or PV power into the grid that could harm anyone working upstream on the power network.
This is called "islanding" mode. Your house and system become an island.
Your PV panels will still produce DC if the sun is shining and feed it into your inverter.
Your inverter will produce AC and feed your house via the EPS output.
If you are producing more PV power than the EPS is using, the inverter will charge the battery simultaneously.

The EPS cutover is about 5 seconds as default.
GivEnergy can change this for you so it acts as UPS (uninterruptible power supply) if you ask them.

EPS requires that the inverter continues to run with no grid power - that's what it's there for. Installer was correct that the normal AC output from the inverter is disabled - possibly for safety reasons, since the people working out on the street would not appreciate the cables being live. Also earthing may not be reliable during a power cut. But with the inverter still running, no reason it can't continue to service the solar panels.

If you search for "UPS" on here, it seems that it is possible to configure it for a faster changeover.

Thanks guys that's very useful.

I don't see any settings to change the switchover time, so I guess I'll try emailing GivEnergy support.

Just to follow up on this, I can confirm that emailing GivEnergy support is what you need to do. They have enabled UPS for me. It is not enabled like this by default to give people time to turn stuff off if they are using more than their battery can supply.

7TheAvenue What would happen if the house was using more than the battery can supply?

Glennh exactly that's why it's not enabled by default. In my case we only have the sockets in a couple of rooms enabled and nothing in there will go over a few hundred watts.

7TheAvenue It is not enabled like this by default to give people time to turn stuff off if they are using more than their battery can supply.

5s isn't really all that much time to get to turn off a high-power device. Reaction time is going to be around that sort of time. Eg everything's just gone dark and you've got to dash through to the kitchen to turn off the kettle.

But my plan is also to leave the kitchen sockets off the EPS, so that there shouldn't be much power drawn.

DD Yeah agree, the 5 seconds thing didn't really make sense to me either!

Glennh I would assume it would just trip the breaker and shut everything down like if you put something on that trips the circuit.