Charging Method - Tab LiFePO4 User Manual

5.3.1. Charging Method

TAB d.d. recommends using the following
charging method.
A. Constant voltage, constant current,
14.6 V +/- 0.2V for a 12 V battery, 29.2 V +/- 0.2 V
for a 24 VDC battery. We recommend to use
TAB d.d. battery chargers with settings at
''Lithium-mode'' for the best result and most safe
and reliable configuration.
B. Multiple or three-stage charging, see graphic
at right, is allowed. TAB d.d. can supply you
with a battery charger with an optimized curve.
We recommend to use TAB d.d. chargers with
settings at ''Lithiummode'' for the best result and
most safe and reliable configuration.
Bulk phase
In this phase the batteries are charged with a constant current up to the end of
charge voltage (Ubulk), If UBulk is reached the charger will automatically switch to
absorption phase. The maximum charge current (Imax) for TAB d.d. batteries is 1C,
however for endurance cycle life TAB d.d. suggests to limit the current to C3
(1C = nominal battery capacity, C3 = 1/3 of nominal capacity). On some chargers the
maximum charger active time (t0) can be programmed. TAB d.d. suggests setting t0
to: t0 = 2*(BTcap / Chcur) Example: Battery capacity = 90Ah, Charger = 45A, set to a
maximum of 2*(90/45) = 2 hours.
Parameter
I
max
t
0
Table 2. Bulk Phase
15
Bulk Phase
Typical Min
-
Depends on the
battery SOC
Bulk Abstorption
min. Bulk timer min. abs timer
V Bulk
V Absorption
V Float
V Ret. to Bulk
Return
Amps
max. Bulk max. Absorption
timer timer
Max Remark
- 1C (90 A)
- 2*(BTcap /
Chcur)
Float Bulk
Return to Bulk charging Return to
Bulk timer timer Bulk timer
=voltage
=current