I would have opted for a PoE system. Perhaps it's time for an upgrade. Decent CCTV NVR's come with onboard PoE in a variety of channels. Eg. 4, 8, 16, 32 and 64 channels. You plug the UPS into a main power outlet, and the NVR into the UPS. A decent size UPS usually has 4 power outlets, so, NVR in one, internet router in another, maybe a small LED light in another, and the other one free for charging a phone. There's plenty of them for sale on Lazada. Here's a random one from the front page. They also come in kits. HikVision (decent brand) 8CH PoE. https://www.lazada.co.th/products/pdp-i3870590673-s14811074345.html?c=&channelLpJumpArgs=&clickTrackInfo=query%253Acctv%252Bnvr%252BPoE%253Bnid%253A3870590673%253Bsrc%253ALazadaMainSrp%253Brn%253A1e321a3f76e386c0388d89b7f1a1b81a%253Bregion%253Ath%253Bsku%253A3870590673_TH%253Bprice%253A3400%253Bclient%253Adesktop%253Bsupplier_id%253A32412%253Bsession_id%253A%253Bbiz_source%253Ah5_internal%253Bslot%253A4%253Butlog_bucket_id%253A470687%253Basc_category_id%253A14399%253Bitem_id%253A3870590673%253Bsku_id%253A14811074345%253Bshop_id%253A2641%253BtemplateInfo%253A107882_A3_E%2523-1_C%2523&freeshipping=0&fs_ab=2&fuse_fs=&lang=en&location=Nonthaburi&price=3.4E%203&priceCompare=skuId%3A14811074345%3Bsource%3Alazada-search-voucher%3Bsn%3A1e321a3f76e386c0388d89b7f1a1b81a%3BoriginPrice%3A340000%3BdisplayPrice%3A340000%3BisGray%3Afalse%3BsinglePromotionId%3A-1%3BsingleToolCode%3AmockedSalePrice%3BvoucherPricePlugin%3A0%3Btimestamp%3A1784203681954&ratingscore=4.777777777777778&request_id=1e321a3f76e386c0388d89b7f1a1b81a&review=18&sale=61&search=1&source=search&spm=a2o4m.searchlist.list.4&stock=1 Then, plug the NVR into a huge UPS like this one, and you are good. (2000Va - 1200 watts) It doesn't have to be this big, but a UPS this size is big enough to run some other electronics during a power outage. https://www.lazada.co.th/products/pdp-i3870590673-s14811074345.html?c=&channelLpJumpArgs=&clickTrackInfo=query%253Acctv%252Bnvr%252BPoE%253Bnid%253A3870590673%253Bsrc%253ALazadaMainSrp%253Brn%253A1e321a3f76e386c0388d89b7f1a1b81a%253Bregion%253Ath%253Bsku%253A3870590673_TH%253Bprice%253A3400%253Bclient%253Adesktop%253Bsupplier_id%253A32412%253Bsession_id%253A%253Bbiz_source%253Ah5_internal%253Bslot%253A4%253Butlog_bucket_id%253A470687%253Basc_category_id%253A14399%253Bitem_id%253A3870590673%253Bsku_id%253A14811074345%253Bshop_id%253A2641%253BtemplateInfo%253A107882_A3_E%2523-1_C%2523&freeshipping=0&fs_ab=2&fuse_fs=&lang=en&location=Nonthaburi&price=3.4E%203&priceCompare=skuId%3A14811074345%3Bsource%3Alazada-search-voucher%3Bsn%3A1e321a3f76e386c0388d89b7f1a1b81a%3BoriginPrice%3A340000%3BdisplayPrice%3A340000%3BisGray%3Afalse%3BsinglePromotionId%3A-1%3BsingleToolCode%3AmockedSalePrice%3BvoucherPricePlugin%3A0%3Btimestamp%3A1784203681954&ratingscore=4.777777777777778&request_id=1e321a3f76e386c0388d89b7f1a1b81a&review=18&sale=61&search=1&source=search&spm=a2o4m.searchlist.list.4&stock=1 The above is all DIY. You do not play around with any 240v.