Battery Faults and Questions in Unity300 SP A(BBU)

EMC - storage SP A to battery failure.

Question 1 - How do I check if I don't see how long the battery has failed in the Alerts and Logs in Events?

Question 2 - SP A Is there an effect on the system if the power is suddenly down during a battery failure?

Question 3 - Does the cache data automatically pass to SP B in the event of an SP A battery failure?

Question 4 - What happens if both of the controllers' batteries fail?

Question 5 - How is the cache memory write mode currently configured on storage? Does one battery change if it's disabled?