Information

Capacity as a function of temperature for CYCLON
®
Battery Single Cells &
Monoblocs (use graph up to 40°C for Monoblocs)
State of charge for CYCLON
®
Battery Single Cells & Monoblocs
Figure 5-2: CYCLON
®
Battery Storage Time Vs. Temperature
Charging recommendations:
Broadly speaking, a battery may be
recharged using either a constant voltage
(CV) charger or a constant current (CC)
charger, or a modification of either or
both of these.
The exact regime chosen generally
depends upon the time and economic
constraints imposed by the system.
Constant current charging is widely used
in cyclic applications where a recharge
must be accomplished in a relatively
short time period. Constant voltage
charging, where a single voltage level
is applied across the battery terminals,
is the most suitable method to recharge
CYCLON
®
batteries. Depending on the
CV charger's current limit, it is possible
to recharge these batteries from a 100%
discharged condition to better than 95%
state of charge in less than one hour,
using only the cyclic charge voltage.
Constant voltage charging
Constant voltage (CV) charging
should be within the following ranges:
Fast Chargers, Per cell:
2.40 to 2.45 volts @ 25°C
12 volts:
14.40 to 14.70 volts @ 25°C
(for a maximum of 16-20 hours)
In cyclic applications, where the battery
is being significantly discharged at a
frequency greater than once per week,
the charge voltage should be a nominal
value of 2.40 Volts per cell (VPC), but can
range between 2.35 VPC and 2.45 VPC
to maximise cycle life.
Float Chargers, Per cell:
2.27 to 2.35 volts @ 25°C
12 volts:
13.62 to 14.10 volts @ 25°C
Nominal float voltage is 2.27 VPC
at 25°C, but float voltage can range
between 2.25 VPC (@25°C) and 2.35
VPC (@25°C) depending on the details
of the application. Voltages nearer 2.35
VPC would be used in applications
which are float in nature, but could have
frequent discharges of significant Depth
of Discharge (DOD).
To avoid thermal runaway in warmer
temperatures, and to improve charge
acceptance in colder temperatures, the
charger voltage should be compensated
by approximately 3 millivolts per cell per
degree Centigrade variance from 25°C.
This is a negative coefficient, with the
voltage being lowered as the temperature
increases, and vice versa.
7
Publication No: EN-CYC-SG-004 - June 2014
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