Battery pack The Lithium battery Charging Light Tower provides up to 8 hours of continuous operation without carbon dioxide emissions, fuel consumption nor noise, thanks to the battery pack. The special dry batteries are able to be recharged in few hours from either an external power source or from the built-in backup generator. Backup generator When the Lithium battery Charging Light Tower light tower has utilized all of the stored energy from the battery pack, the diesel backup generator will automatically start, providing all the energy required to power the lamps and at the same time recharging the battery pack. When the battery pack is fully recharged, the generator will automatically turn off.