Rechargeable Energy Storage
The trip to the lunar surface will last approximately 3.5 days where the vehicle will experience a one hour long eclipse of the sun by the Earth, and several shorter eclipses of the sun by the moon.  Once Googol has landed on the moon, the sun will be in full view for the next 26 days without interruption.  A solar PV-battery system suits this type of mission very well by charging the batteries and running system power strictly from the solar panels during times when the sun is in view, and operating the vehicle strictly from battery power when an eclipse is taking place.

We chose Li-ion MicroSat batteries from Saft Batteries Inc.  Again, these batteries are space-proven and come as a self regulating module.  Therefore, there is no need to include the added weight and cost of a charge/discharge (C/D) module in the power management and distribution (PMAD) system.  These batteries will have a capacity of 16.8 Ah and a nominal energy level of 480 Wh.  This power is enough to sustain operations on the vehicle for more than two hours of darkness.  The figure below shows the battery module that will be used as the primary power backup onboard the Googol lander.