UPS Backup uses a lot of electricity when charging the battery but only when doing so when the battery is finished charging and there is no load shedding, whereby the accessories one has only use the power stored up on the battery.
UPS in full is, Uninterruptible Power Supply/Source, a gadget or battery that acts as a stoppage/backup or protection when the normal power supply is interrupted, fails, or drops to an unacceptable voltage