UPDATE1.
Met with Bitcoin Mining Specialist, (he had upto 100 Rigs at our town,
i saw his farm, he was using SINEWAVE UPS 2000VA for every RIG, from more than a year..
so i bought it and tested, it is giving 40 mins of Backup on 4gtx 1070 with OC and still going on power outage (havent test till last)
it have multiple MCB, and i tested to DIM the current and voltage and other various task to which can harm rig,
it gave well safety..
using 2 batteries of 12V of EXIDE brand
and inverter of SUKAM brand both with 2 years warranty,
saw the box, was labelled as for "heavy Computers"
this saved my investment alot,
it took 238$ to setup it..