PowerWall Charge Rate & TOU Tariffs

We have PowerWalls (4) and are on the Octopus GO TOU tariff with 4 cheap rate hours at night.

However, each PowerWall would only charge at 1.7kW when forced to charge by setting a high Reserve % and this is half the charge rate (3.5kW) specified in the PowerWall Tech Spec.

As a result, it is not possible to take full advantage of the Octopus GO 4 cheap rate hours – each PowerWall has a capacity of 13.5kWh.

I‘ve got nowhere with their Tech guys.

But I’m mildly pleased to report that during the last few days that limit seems to have increased to 1.8kW – a small but welcome improvement.

What are the experiences of other Forum users with PowerWalls?

How to pressurise Tesla to honour their PowerWall Tech Spec?

Ideas/comments?