If the keypad is showing "LO -BATT" this means the battery in the black box, installed in your dispensers has drained down to the set voltage where it needs to be replaced.
When you see this message report it to the manager and or the maintenance personnel for your store.
The black boxes use a CR123a battery normally used in digital cameras, this could be sourced locally or ordered from Know Control.
Once all the batteries, that were displaying low, have been replaced you should perform a sensor reset from the keypad by holding down the #2 button until it asks for your access code. Enter the code and it will show once the rest is complete. Now the messages should be cleared.