Elon Musk says
@SpaceX AI Satellites will now include batteries for power assistance.
That enabled peak power to rise from 150 kW, to 230 kW (67% increase). The batteries will be charged using the abundant solar energy available 24/7 in space.
This will lower the number of satellites needed to reach a certain compute threshold. Elon already has immense expertise with batteries, so this makes perfect sense (basically reduces launch costs, manufacturing volume, etc).
I wonder what batteries they will use and the capacity, LFP? Probably most likely.