uninterrupt power supply is mainly use for short time .means according to ups VA it gives backup.
ups is also two types :
- on line.
- offline.
online ups having high volt and amp for long time backup with with high dc voltage.but ups start with 2v dc with 7 amp. but inverter is startwith 2v,24,dc to 36v dc and 20amp to 80amp battery with long time backup.