It's not common to see a +48v/-48v bipolar power supply. But, charging a +96v/0v is no different than charging a +48v/-48v system. Isolated components (those that do not bond one rail or the other to its case and expect that to be the 0v reference/safety ground) work in either configuration. Non-isolated components are not suitable for use in a bipolar power supply system but work in a normal system. In either case, you still need the voltage difference to go up to ~116vdc to get a full charge. The same solar array configuration will work for both. Btw, I don't use two 48v chargers in series to get 96v, just isolated 96v chargers.?
Randy Cain