The HPE Smart Storage Battery is a lithium-ion, low-halogen centralized backup source and is required to backup the write cache content onto flash memory on the HPE Smart Array Gen10 and Gen9 performance RAID (P-class) controllers in case of an unplanned server power loss. The battery is also the backup power source for HPE NVDIMMS and allows any data in flight on the DRAM to be moved to the non-volatile NAND flash. Only one battery is required per server as it can support multiple devices.