The SCXI-1161 is composed of 8 SPDT relays. If you want to drain a battery, you will want to connect a load to it.
If you want to be able to take the load off of the battery, you'll need to break the circuit which you can do by using one of the relays of the 1161. When you close the switch, the load is applied and when you open it, the circuit is broken.
Hope this helps.
Jack A.