Added a refurb 2nd battery and have finally found my charge limit with just hitting the 90-100% charge rate curve reduction in the last 15 minutes.
We've a 5hr cheap slot on Octopus Go from 0030-0530
Battery went from 8% to 92%, so a 84% charge increase.
17.2kW added, or 3.44kW per hour. That's enough for us for a day, and any additional solor can/will charge the remainder, although it would be more cost effective to export it than charge.
84% and 17.2kW gives the 2* 9.5's notional batteries capacity of 20.5kW when full.


