Well in reality it does not matter if the combined voltage will drop in the batteries. I'm sure it will since there are losses. The thing that really matters is, can even 1% of the energy running trough a load be recycled back into the batteries? I'm sure it can and will. I'm testing my own setup soon. And I did some test with a few 22k Mf caps and it does work. So I presume it will also in a battery setup. only difficulty in a battery is that it is hard to 'really' know how much energy it holds. In cap that is much less of a problem.

To me the whole T. Switch idea is "using the energy recycling to power a load longer with the same available energy" And it won't matter if the batteries loose power, as long as they do more work than the rate of discharge.

Kind regards,
Steven