I don't have racks so I went free-standing like the picture below (with APC 3000 +Chargery 16 BMS) - which are more 'consumer' than 'professional' grade. However, battery wise, I'm guessingthey are all 24v or 48v nominal. @Korishan has pointed out that some models of the professional grade will even let you set things like charge voltage max - but I don't know of a specific model to share.Overmind said:@OffGridInTheCity are these rackmount (high quality) like these: www.forit.ro/ups-uri/apc/196687-smart-ups-1500va-lcd-rm-2u-230v-smartconnect/ or just standard cheap versions