Equalizing And Corrective Equalization

EQUALIZATION: Individual cell readings will vary slightly in specific gravity after a charging cycle. Equalization, or a “controlled overcharge”, is required to bring each battery plate to a fully charged condition. This reduces stratification and buildup of sulphation on the plates; two circumstances that shorten battery life. One of the most commonly asked questions is “When is it time to equalize my battery bank?“ As usage is unique for each system, this will depend on several factors including depth of discharge, cycle frequency, operating temperature, charging voltage and current. Monitor specific gravity and voltage regularly as these readings will indicate when an equalization may be necessary. An Equalization should be completed when the specific gravity of individual cells within the battery bank are varied by more than .025 -.030.(Ex. 1.265, 1.235, 1.260, 1.210…) Do not attempt to equalize a battery bank with failed cells or missing batteries as this will force an overcharge on the remaining cells which may cause permanent damage. When resting in Float charge, if specific gravity readings are consistently lower than recommended it may be necessary to adjust Bulk/Absorption voltages slightly and/or Absorption time to increase charge time. To properly equalize the battery bank, follow the Correction Equalization procedure using the recommended Equalization set point in Table 2 (a) & 2 (b) Flooded Charging Parameters starting at the lower end of the provided voltage range.

CORRECTIVE EQUALIZATION: Corrective Equalizations should be performed when the battery bank is at 100% SOC. Review and complete the provided preparations before initiating the Equalization charge. Equalization time will vary depending on the level of sulphation, balance of charge, size of the battery bank and available charging source. Typically, a corrective Equalization is necessary every 60 to 180 days to de-sulphate and balance a battery bank in systems which are deficit cycled and/or charged at lower charge currents. If multiple parallel strings show charge imbalance it may be necessary to equalize each string individually. It is important to monitor specific gravity and voltage throughout the Equalization process. When specific gravity readings remain constant for 45-60 minutes this generally indicates completion.

Never try to equalize AGM batteries!

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