Rockwell Automation 1606-XLS240UPSD Power Supply Reference Manual - Manual (Page 23)

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.
Rockwell Automation Publication 1606-RM017A-EN-P — February 2014 23
Bulletin 1606 Switched Mode Power Supplies
26. Application Notes
26.1. Battery Replacement Intervals
Batteries have a limited life time. They degrade slowly beginning from the production and need to be replaced
periodically. The design life figures can be found in the individual datasheets of the batteries and are usually specified
according to the Eurobat guideline or according to specifications from the manufacturer.
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 guidelines, design lives have been structured into the
following different groups:
3 - 5 years:
This group of batteries is very popular in standby 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 usually us ed 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 that require longest life and highest safety levels.
This represents a 11 years design life with a production tolerance of ± one year.
A battery failure within the specified design life of the battery usually results in a complete loss of the battery
function (broken cell, faulty connection, …) and will be detected and reported by the periodical battery tests which
are included in the 1606-XLS240-UPSD DC-UPS control unit.
If the operational parameters differ from those which are specified for the design life, earlier replacement of the
battery might be necessary. The “real life” is also 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 faster; further
use of the battery is therefore not recommended.
Temperature effect:
The temperature has the most impact on service life. The hotter the temperature, the sooner the wear-out phase of
the battery begins. The wear-out results in a degradation of battery capacity. See Fig. 26-1 for details.
Effect of discharging cycles
The number as well as the depth of discharging cycles is limited. A replacement of the battery might be necessary
earlier than the calculated service life if the battery exceeds the numbers and values of Fig. 26-2.
Other effects which shortens the service life
Overcharging and deep discharging shortens the service life and should be avoided. Thanks to the single
battery concept of the 1606-XLS240-UPSD, the end-of-charge-voltage can be set very precisely to the required
value and thereby avoiding unnecessary aging effects.
Charge retention is important to ensure the longest battery life. Stored batteries that are not fully charged
age faster then charged batteries. Batteries which are not in use should be recharged at least once a year.
Excessive float charge ripple across the battery has an effect of reducing life and performance. The
1606-XLS240-UPSD does not produce such a ripple voltage. This effect can be ignored when the battery
is charged via the 1606-XLS240-UPSD.
Guidelines for a long battery service life
Place the battery in a cool location: E.g. 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 capacity immediately higher than absolutely
required. The depth of discharge reduces the service life of the battery and limits the number of cycles.
See Fig. 26-2.