total motor kw-100kw,crane class-m6,the crane should be operated on ups as the conventional electric supply is off , back up time require-30 min.
About 4200 AH( TOTAL) is required with 12 V batteries.
To account for the inefficiencies, and startup currents, you should have a 200 kW (200 kVA) inverter with peak power of 800 kW. The batteries would have to store and deliver about 150 kW. But lead acid batteries would need to be of a higher capacity to guarantee that power level for 1/2 hour, which calculates to 75 kW-hour. I'd say 100 kW-hour capacity. A large 12 volt battery can store about 100 amp-hours which translates to 1 kW-hour, so you would need 100 of this size batteries connected in series/parallel. I made a lot of guesses, you should get better numbers for the motors, the inverters and batteries for a more accurate calculation. An inverter of the size needed will not be a 12 volt unit, but probably 48 or 96 volts DC. so you need to configure your batteries in series parallel to get that voltage. Altogether, the 100 large batteries make this not a practical solution. There are lots of large cranes in the world, what do they use for backup? And why do you need backup. With no power, the clutches would keep the crane and loads fixed in position, my guess.
