Switching to battery power

I’ve done it before: fully off-grid battery powered audio system. At the moment, my preamps are the only thing on the grid when I’m playing music. Long story short - battery power done right can sound fantastically smooth and detailed. Where it seems to lack (unless you put a lot of effort into it) is with musical transients - like the smack of a kick drum. Right now I find myself enjoying classical music the most - the harmonics are so full and rich! I don’t seem to enjoy music as much that has extremely demanding transients. It’s a bit hard to explain because batteries have plenty of current capacity - I’ve accidentally melted copper wire before when wiring up batteries. I think it has to do with having too few amp-hours, the high internal resistance of the batteries, etc. It’s hard to compete with the grid in that regard. Sitting between 120 volts with megawatt size generators providing the voltage and current isn’t too shabby. I’ve got to wonder how large battery banks and/or capacitors/supercaps would sound.