Current setup is I have a 4KVA stabilizer for high voltage which is 255+ V most of time. I've tried a lot to get the electricity people to get it to 230V but it again becomes 250+V after 24 hrs. I tried everything and gave up. due to price hike in electricity units, each and every extra thing i run adds up in watts used per day and i'm looking at bills in 1.2k+ every month. each of these things - stabilizer, ups, inverter all have transformers in them and each will lose some conversion efficiency. All of them add up in load on meter. So i'm thinking of removing everything and keeping just one thing to deal with high voltage and give backup to home in power failure for around 12 hrs. Is there something I can put at mains that will run on external 150Ah lead acid battery to replace the voltage stabilizer, 850va apc inverter and the 650va apc ups i'm using? will a single 1KVA online ups do the job?