What is the storage life for stationary batteries?
Answer: The storage interval from date of shipment to date of installation and initial charge should not exceed six (6) months. If stored at temperatures 77 degrees F or below, the battery should be given its initial charge at or before 6 months and recharged at 6 month intervals.
Will the battery be adversely affected if stored at warmer temperatures?
Answer: Yes. For every 18 degrees F above 77 degrees, the time interval for the initial charge and recharge should be halved. If a battery was stored at 95 degrees F the maximum storage interval would be 3 months. Storage beyond these periods without proper charge can result in excessive sulfating of plates and positive grid corrosion which is detrimental to battery performance and life.
What kind of battery testing should be performed to insure that I have enough battery backup?
Answer: There are a number of good testing methods available, i.e., resistance, impedance, and conductance which will provide good indicators of the strength of one battery cell compared to the next or how your battery today compares with itself when it was new (as long as initial readings were taken). These tests however do not provide a true indication of the capacity of the battery.
The best and only way to truly test battery capacity is to apply a load test by either using the load of the equipment being backed up or by using a resistive load bank. This test when performed per IEEE specifications will provide the owner with the facts required to determine whether or not a battery needs to be replaced.
What are the minimum battery requirements to maintain my warranty?
Answer: This varies by manufacturer. At a minimum, the user is required to annually measure and record voltage and temperature readings. Some manufacturers also require specific gravity readings (flooded battery) and cyclic readings (how many times the battery is discharged and recharged).
What considerations should I use when deciding between sealed batteries vs. flooded batteries?
Answer: The sealed batteries (VRLA- valve regulated lead acid) have come along ways since their entrance into the backup power industry in the late 70’s. Many have used this battery successfully for years. The advantages over the flooded battery being; the minimal amount of maintenance required, the smaller footprint for the same capacity, the minimal amount of gassing under normal conditions, ease of installation and an easing of requirements for spill containment and venting.
The flooded battery on the other hand has been around for over a hundred years and many feel that it is more reliable and worth the added expense involved in freight, installation, maintenance, etc. Application and personal preference play a big part in this decision.
What is the difference between and VRLA and a flooded lead acid battery?
Answer: The flooded battery is enclosed in a clear plastic jar. The negative and positive plates are completely immersed in electrolyte. The specific gravities are generally either 1.215 (for a low and medium discharge rate) and 1.250 (for a high rate of discharge). The plates are separated by a rubber separator. By design the flooded battery gasses during the charging and discharging process. This requires that additional water (distilled or I/O) be added as needed. Because of its gassing nature, copper that is not plated or protected is more likely to develop corrosion. Just these two items explain why the maintenance demands on a flooded battery are greater than a VRLA.
The VRLA battery is available in basically two types; silicone gel (commonly referred to as a gel cell) and AGM (absorbent glass mat-not a gel cell). Both batteries are sealed so that the escaping of moisture is reduced. As the battery charges and discharges it creates gas, as the flooded product, but through the recombination process the moisture stays within the cell. If the gassing is excessive (caused by high heats or excessive charging) the gasses may release through the vent cap (valve) located between the posts of the cell. This should be minimized as much as possible to prevent premature failure of the battery. The plates are separated by the glass matting in the case of the AGM and a rubber separator in the case of the gel cell, like that used in the flooded cell. Maintenance is still required in the VRLA product but is greatly reduced because of its non-gassing nature.