I have an old equallogic internally running testing - which I don't want to turn off or restart at the moment.  Meaning a replace of battery without turning off the SAN:

I have a battery failure, and have a challenge to pick the correct Controller module to pull from SAN, ref Fig 1 and Fig 2 below.

Fig 1. There is a battery failure in Secondary Controller Module/Type14

 

It does not specify which is the secondary module from the back of the SAN, ref Fig2 below.  My thinking was that the secondary module would be the one with no activity:  But bottom module shows activity on the ethernet while the top module I connect to via the management port and shows activity on the management port.  FYI I pulled the management cable from the top module - and I could not connect to the SAN. It seems both modules are in use? Pull Top Module or Bottom Module for battery replacement?    Please advice. 

Fig2.