Its an interesting point that you have made about the quantity of coolant in the system.
We conducted many experiments, including adding resevoirs to dramatically increase the amount of water in the system.
We found that this makes no diiference to the cooling effect, but simply adds weight and complexity to the system. Perhaps surprisingly when you first think about it, we also found that the flow rate has practically no effect on the efficiency of the system either.
The most critical thing is the design of the radiator and internal design of the cooling manifold. Through careful development of these parts we have been able to gain the most advantade, and make the system extremely effective.
A typical twin fan setup, which many drivers use, will lower the temp about 8 or 9 degs Celcius and draws 250-300mA from your cells (about 2 watts)
The TCS will typically reduce temperatures by 20 degs Celcius and in some circumstances a lot more, yet only draws 40mA (less than 0.5 watts).
Please look at the site where we have added some other background information http://www.tcscooling.com/data.html
Hope this helps