Methods Of Preventing Over-Discharge
The following precautions must be taken to prevent over-discharging a battery.
The battery surface (particularly its top) should always be kept clean and dry.
The terminal connections should be clean and tight.
At every routine maintenance, check the electrolyte level.
This also applies to batteries designated as "low maintenance" and "maintenance-free".
When the vehicle is not going to be used over a long period of time, disconnect the negative battery terminal. (If the vehicle has an extended storage switch, turn it off.)
Check the charge condition of the battery.
Periodically check the specific gravity of the electrolyte. Keep a close check on charge condition to prevent over-discharge.