Flooded lead acid batteries are designed for long life and high performance – as long as users follow a watering plan. Battery watering doesn't have to be complicated! In fact, it can actually be a simple process if you follow these basic battery watering rules.
Neglecting to water your battery will cause damage. For instance, overwatering dilutes sulfuric acid inside the battery, hindering performance. Under watering slashes lifespan and runtime. Fortunately, the solution to both these problems is simple: Maintain liquid levels above the top of battery plates, but not above the battery cover vent well.
Here are some keys to battery watering:
Always wear Personal Protective Equipment (PPE), including safety glasses, gloves, and long sleeves
Use only distilled or demineralized water (never add battery acid)
Only water after charging is complete (watering before charging may cause battery electrolytes to overflow, a chemical spill that also diminishes battery capacity)
If battery plates are uncovered or not submerged electrolyte, do not charge them. Instead, fill batteries until just the tops of the battery plates are covered with liquid. Then they are ready for charging.
Now, watering schedules will vary based on the operating environment, battery age, and temperature. Ask your manufacturer or installer for recommendations – and be sure to put routine maintenance in your calendar.
Finally, consider a battery watering system
For instance, many Crown deep cycle batteries include the PROeye watering indicator, which can be inspected after charging or before starting a duty cycle. (Green means no watering is required; all clear or white means it’s time to check fluid levels.)