« Back to Battery 101

Equalizing (Flooded batteries only)

Many experts recommend that batteries be equalized periodically, ranging anywhere from once a month to once or twice per year. However, we only recommend equalizing when low or wide ranging specific gravity (± .015) is detected after fully charging a battery.

Equalizing is an over voltage - overcharge performed on flooded lead acid batteries after they have been fully charged. It helps to eliminate stratification – the uneven distribution of acid - and sulfation – the build up of sulfate crystals on the plates. These are two of many conditions that can reduce the overall performance and life of a flooded battery. An Equalize charge – or equalizing – should only be used on flooded batteries when specific gravity readings vary from cell to cell at +/-.015 on a fully charged battery. 

Equalize charging should not be performed on AGM or GEL batteries. Balance Charge modes are included in all our Discover® Industrial, Commercial and Electric Vehicle charges. Balance Charging is similar to an equalize charge cycle but is performed at formulated and temperature compensated voltage, time and current data.

Step by Step Equalizing

  • Verify the battery(s) are flooded type
  • Remove all loads from the batteries
  • Connect battery charger
  • Set charger to equalizing mode
  • Start charging batteries
  • Batteries will begin gassing and bubbling vigorously
  • Take specific gravity readings every hour
  • Equalization is complete when specific gravity values no longer rise during the gassing stage

Note: Many chargers do not have an equalization setting so this procedure can’t be carried out.

General Lead Acid Battery Description
General Lead Acid Battery Applications
General Lead Acid Battery Types
General Lead Acid Battery Chemistry
Discover® Sealed Valve Regulated Lead Acid Batteries
Discover® Deep Cycle AGM Battery
Discover®700 Series Dry Cell Battery
Discover® EV Traction Dry Cell Battery
General Benefits and Features of Discover Valve Regulated Lead Acid (VRLA) Technology
Sales Channels for Discover Battery Technologies
Things to question when making a battery buying decision
What to consider when buying a deep cycle battery
Information gathering before buying batteries
Calculating cost to own when purchasing batteries
Safety First
Safety and Productivity
When working with batteries
When handling battery acid
When installing or replacing batteries
When booster cables are used
Danger of exploding batteries
Warning and warning labels
Parallel connections for sophisticated users and installers
Parallel connections for unsophisticated users and installers
When charging batteries
Selecting a charger
General charging information for AGM and GEL batteries
GEL battery charging
AGM battery charging
Equalizing (Flooded batteries only)
Typical self-discharge of VRLA batteries at different temperatures
Typical self-discharge of high quality deep cycle flooded batteries at different temperatures
How much will a system cost for my 2000 square foot home?
Can I use all of my normal 120/240 VAC appliances?
What components do I need for a grid-tie system?
What components do I need for a complete solar system?
What type of solar module mounting structure should I use?
Where should I mount the solar modules and what direction should I face them?
Should I set my system’s battery bank up at 12, 24 or 48 VDC?
Should I wire my home for AC or DC loads?
Can I use PV to heat water or for space heating?
How do solar panels (cells) generate electricity?
Will solar work in my location?
Tables & Figures