User Manual

RS02109/0814/CD 18 www.cdtechno.com
8.3 Equalize or Freshening Charging
8.3.1 Equalize or Fres he ning Charge Fl oa t Charge Appli c ati ons
Under normal float char ge operating conditions, it is not necessary to e quali z e or freshen the Liberty
2V batteries when used within the criteria described in sections 5.2 and 7.
NOTE:
Some hydrogen gas may be liberated
at equalize charging voltage.
An equalizing charge should be performed if individual cell voltages fall 0.05 volts below the averag e float
voltage as specified in Table 1 (Section 7.1). Presence of a minimum voltage does not imply a battery is
malfunctioning or that it will not pr ovide the necessary power when called upon.
NOTE:
Charging current to the battery should be limited based on the Am pere Hour capacity of the battery.
Refer to Table 1 for maximum charging current.Higher charging current could potentially destr oy the
battery by overheating that subsequently causes more current to flow creating a cycle sometimes
referred to as “thermal runaw ay”.
8.3.2 Equalize or Fres he ning Charge Cyclic Applic at ions
In cycle charge applications, depending on how the system is designed
the batteries are regularly discharged and regularly re-charged. In these applications, the charging system
should be sized so that, on the average, the battery is returned to between 85 to 90% state of charge daily.
On a bi-weekly to monthly basis the battery should be charged to 100% or fully charged state using the
equalization parameters outline in Table 1 (Section 7.1) for equalization/freshening charge for 2V Liber ty DCS.
If the system is a solar-only system then the charging strategy is solely based on the photovoltaic panels
returning all of the energy to t he battery every day. The ratio to the photovoltaic array to the load during the
worst conditions should be able to bring the batteries to full charge at least once a month.
If the system is a hybrid system where there is dispatchable batt ery charging capability, the batteries should
be charged to between 85 and 90% of full charge on a daily basis (daily charge). Monthly they should be given
an equalization charge to insure that they were fully charged and the SoC is re s et.
NOTE:
Use the equalize voltage setting as shown in Table 1 (Section 7.1) for a period not exceeding the
specified hours depending on service conditions.
Consult your C&D Technol ogies Representative for additional information.