Hi, Thanks for your question about the VNX battery. You should be able to do one at a time.          Let us know if you have any additional questions. 
Hi guys, sorry, my English is not very good.  I have both SPS failures on VNX7500, I have both new batteries for repayment and will replace two SPS, I'd like to know if I can replace both SPS online, I replace SPS A end wait for the charger then after charge, I replace SPS B, or if I need shutdown the VNX? I downloaded the procedure on solve but there it only mentions changing a battery
Replace both sps on vnx