batteries

Following is a summary of the characteristics of popular battery technologies. For more details, see lead acid, nickel cadmium, nickel metal hydride, lithium ion, lithium polymer, zinc air, CMOS battery and memory effect.

  CHARACTERISTICS OF RECHARGEABLE BATTERIES

                      Recharge  Fast     Self
            Energy    Cycles    Charge   Discharge
            Density   To 80%    Time     Per
            (Wh/Kg)*  Capacity  (hours)  Month

 Nickel
  Cadmium    45-80       1500       1      20%

 Nickel
  Metal
   Hydride  60-120    300-500     2-4      30%

 Lithium
  Ion      110-160    300-500     2-4      10%

 Lithium
  Polymer  100-130    300-500     2-4      10%

 Lead Acid   30-50    200-300     8-16      5%

                      To 50%
                      Capacity

  Reusable
  Alkaline      80         50     2-3      0.3%


  This data is provided courtesy of
  Cadex Electronics Inc. (www.cadex.com).

  * Wh/Kg = watt hours per kilogram

A Whole Lotta Batteries

This roomful of lead acid batteries stands ready to drain itself entirely in less than a minute. It serves as interim power for a large datacenter between the time a power outage has been detected and the generators can come up to full speed.