Rockwell Automation 1606-XL240-UPSE Power Supply Reference Manual - Manual (Page 20)

All parameters are specified at an input voltage of 24V, 10A output load, 25°C ambient and after a 5 minutes run-in time unless noted otherwise.
It is assumed that the input power source can deliver a sufficient output current.
20 Rockwell Automation Publication 1606-RM013A-EN-P — March 2014
Bulletin 1606 Switched Mode Power Supplies
27. Application Notes
27.1. Battery Replacement Intervals
Batteries have a limited lifetime. They degrade slowly beginning from the production and need to be replaced
periodically, The design life figures can be found in the indidividual battery datasheets and are usually specified according
to the Eurobat guideline or according to the manufacturer’s specifications.
The design life is the estimated life based on laboratory condition, and is quoted at 20°C using the manufacturer’s
recommended float voltage condition. According to the Eurobat guideline, design lives have been structured into the
following distinct groups:
3 - 5 years:
This group of batteries is very popular in stand-by applications and in small emergency equipment.
This represents a 4 years design life with a production tolerance of ±1 year.
6 - 9 years: This group of batteries is generally used when an improved life is required.
This represents a 7.5 years design life with a production tolerance of ±1.5 years.
10 - 12 years: This group of batteries is used in applications for which longest life and highest safety level are
required. This represents a 11 years design life with a production tolerance of ±1 year.
A battery failure within the specified design life of the battery usually results in complete loss of battery
function (broken cell, faulty connection, …) and will be detected and reported by the periodical battery tests
included in the 1606-XLS240-UPSE DC-UPS control unit.
If the operational parameters differ from those specified for the design life, earlier replacement of the battery may prove
necessary. The “real life” is called service life and is defined as the point at which the cell’s actual capacity has reached
80% of its nominal capacity. At the end of the service life, capacity degrades much more rapidly, so that further use of
the battery is not recommended.
Temperature effect
Temperature has the greatest impact on service life of a battery. The hotter the temperature, the earlier the wear-out phase of the
battery begins. The wear-out results in a degradation of battery capacity. See Fig 27-1 for details.
Effect of discharging cycles
The number as well as the depth of discharging cycles is limited. Replacing the battery may prove necessary earlier than the
calculated service life if the battery exceeds the numbers and values in Fig. 27-2.
Other factors shortening service life
Overcharging and deep discharging shortens the service life and should be avoided. Thanks to the single battery
concept of the 1606-XLS240-UPSE, the end-of-charge-voltage can be set very precisely to the required value, thereby
preventing unnecessary aging effects.
Charge retention is important to achieve the longest battery life. Stored batteries not fully charged age faster than
fully charged batteries. Batteries which are not in use should be recharged at least once a year.
Excessive float charge ripple across the battery has the ffect of reducing life and performance. The 1606-XLS240-UPSE
does not produce such a ripple voltage. This effect may therefore safely be ignored if you’re charging a battery with
your 1606-XLS240-UPSE.
Guidelines for long battery service life
Place the battery in a cool location, for instance near the bottom of the control cabinet.
Do not place the battery near heat generating devices.
Do not store discharged batteries.
Do not discharge the battery more than necessary. Set buffer time limiter to the required buffer time.
When choosing the battery capacity, always try to get the next higher capacity than the one you require.
The depth of discharge reduces the battery service life and limits the number of cycles. See Fig. 27-2.