163.3 Battery Backup Unit(1) Battery switchIf the battery switch is set to ON, the battery backup power is supplied to the cache memory at theoccurrence of a power interruption. Turn on this switch before the disk array unit is used.The battery switch may not be turned off if the power of the disk array unit is turned off.If the battery switch is set to OFF, the battery backup power for the cachememory is not provided at the occurrence of a power interruption.Turning off the battery backup unit disables write cache feature.(2) Check terminalThe check terminal is provided for maintenance inspection of the battery backup unit.Note - This terminal is exclusively used for maintenance.(3) HandleHold the handle to pull out the battery backup unit when it is replaced due to failure or the end of thebattery’s service life.When inserting the battery backup unit into the array controller, push it as faras it will go and then secure it with the screws.Incorrect insertion may cause a battery backup unit failure. .(1) Battery switch(2) Check terminal(3) Handle