So, they have sacrificed running time (the ampage of the system) by increasing the charge rate drastically? That's not going to solve the problem, it will create an altogether new one.
The problem that you face with batteries in long draw applications like cars and, in this scenario, trams, is that you are depleting a power source through usage. For example, you have a 120 amp battery and your current draw is 10 amp per hour; you are, before you completely flatten the battery, going to get 12 hours running time. But it is not as simple as that; the voltage will deteriorate way before the 12th hour has arrived, meaning that you cannot access the power and therefore your running time is reduced even further. So, and I see what they have done here, by have a 'quick' 30 second charge every stop, they keep the bank of batteries in a fully charged condition so that the running time of the batteries can be accessed.
That said, you're only creating surface charge on the batteries. You would not, in that time scale, recover the ampage, only the voltage that has been drawn. Start the motor, and you loose the surface charge and you're back to square one. It would be no different to using a jump pack on your car when you have a flat battery. Therefore, if you're not the ampage in the system but maintaining the voltage, then you would need a very high ampage to compensate for the distances the tram will travel.
Which brings me to my main concern. You either have a high voltage with low amps, or a low voltage with high amps. You cannot, in the same physical space, cram a 12v 500amp system with anything higher than a 24v 250amp system. It's simply not the case. 760v is a ridiculously high voltage; what is the ampage and running time that the tram would have at such a rate? Why not have access to twice the running time at 380v? Also, at 760v, imagine the heat generated for the bank of batteries. You get a bad cell or internal short, you're going to have a problem.
