Costs to add extra battery?

I've currently got an AC Coupled 5.2kWh GivEnergy system to complement our solar (GEN2 battery and GEN1 inverter). I recently purchased an additional 5.2kWh battery for this (albeit only GEN1), but I'm just wondering, does anybody know how much spark's charge to simply add an extra battery to an existing system?

Also, do engineers need special access to GivEnergy's online systems to do this? I only ask as our original installer had all of that, but he lives a long way away and so just the travel costs make him uneconomic to use.

I've emailed a few of GivEnergy's supporting sparkys around southern Dorset, but so far none have replied.

I think there is another post similar to this, finding a sparkie to install hardware purchased yourself seems to be hard going. But answers would be a couple of hundred, the sparky can call GE to start a calibration.

However given problems with GE kit at the moment if the purchase is very recent I would consider sending it back until they sort themselves out.