I've gotten rid of my big water tank (which hadn't been used for years) so now I've got room to move the current 25kWh AERL battery outside to free up space in the garage, and of course to help reduce any possible fire risk.
Plus the Australian government has just turned on the free money printer and is subsidising home batteries.
Peter from AERL tells me that installing an additional 50kWh battery would be basically the same price as an extra 25kWh, so I might as well max it the benefit, giving me 75kWh

I'll wait to see what he comes back with in terms of housing the batteries, I might be able to consolidate the housing, as my current 5x5kWh batteries are in the indoor only rated rack.
My 25kWh so far has been adequate on some days, and not enough on other days.
Also, with my new 3 hour free charging window, with the 5kW Deye I can only get 15kWh free a day, the rest has to come from the panel excess.
And the 5kW Deye has been a bottleneck, no to mention my issues with it, so I'll be replacing that with another brand, preferably 10kW (will need a cable pull upgrade).
Peter is recommending this 8kW Solis:
https://www.solisinverters.au/product_detail/S6-EH1P(3-8)K-L-PLUS-AUThat will give me 24kWh/day for free from the grid which is nice.
Looks decent, apparently it's a 5th gen product compared to Deye being a 1st gen product. Still made in China though

It does support the grid side AC coupling, microinverter on gen port, and charge timers that I need.