As shown in this photo it is battery bank used to supply control power for panel switchboard. it is a unit consists of 1.7 x 40 no’s with a total of 110 supply. Each and battery should be connected with alternative phasing and + and – phases output will be connected to panel J and H. If these units kept with better 25-27 temperature and with less dust it can guarantee for 5 years with minimum service.
The maintenance is very simple. You can simply change the battery easily if any issue comes up. The supporting rack is made out of L angels and its is less heavy .