Equalizing Flooded Batteries
BATTERY EQUALIZING:There are three phases of battery charging: bulk, absorption and float. - The bulk stage is where you can give the battery whatever current it will accept not to exceed 20% of the ampere hour rating, and that will not cause overheating. - The absorption phase is voltage-regulated current charging until the battery is fully charged. This is normally when the charging current drops off to 1% or less of the ampere hour capacity of the battery. For example, end current for a 225 Amp/Hour battery is 2.25 Amps or less. - Float charging at a lower voltage is used to maintain a fully charged battery.Equalizing is a controlled (2-5% of 20 Hr A/H rating) overcharge, to equalize and balance the voltage and specific gravity in each cell of a Flooded Lead Acid Battery. Equalizing reverses the build-up of the chemical effects like Stratification (where acid concentration is greater in the bottom of the battery), and Sulfation (where sulfate crystals build up on the plates).The frequency recommendation varies by manufacturer from once a month to once a year, 50 to 100 deep cycles, or a specific gravity difference between cells of .03 or .015 volts (15 millivolts). Trojan, for instance, recommends equalizing only when low (or wide ranging) Specific Gravity (±0.015) are detected, after fully charging the battery.1. Verify that the battery is a Flooded Type - Do NOT equalize VRLA Batteries!2. Fully charge the battery.3. Remove all loads from the battery(s).4. Connect battery charger.5. Set charger for equalizing voltage (A) .6. Start charging.7. Batteries will begin vigorous bubbling & gassing.8. Check Specific Gravity (in each cell) hourly.8. Equalization is complete when S.G. stops rising while battery gassing.9. Add distilled water to fill line (equalizing uses water).Note ‘A’:Most of the new Multi-Stage Battery Chargers have an automatic “Equalize” mode. If you have a constant current - variable voltage charger, you can set the charge voltage to the specific Battery manufacturer’s specifications; or approximately 15.1 V for “SLI” Batteries, or 15.8 V for “Deep Cycle" Batteries).HTH,Gord