Sharp VL-E610S Service Manual page 118

The timer is set to 180 minutes time limit to avoid overcharge which may be caused by -∆V detection error.
Here, -∆V detection is set to 40 to 80mV.
The third stage is trickle charging. In this mode, the fully charged state is kept even after the quick charging is
completed.
The trickle charging is generally set at 1/30 to 1/40C depending on the characteristics of battery. This adapter adopts
the charging system which is controlled by the constant voltage control operation output and fixed resistance.
These charging stages are shown in Figure 12-1-2.
3.Nickel-hydrogen battery charging mode
When the nickel-hydrogen battery is attached to the adapter to which the DC plug is not attached, existence of T
terminal is detected, and the quick charging of nickel-hydrogen is started.
The charging of the nickel-hydrogen battery has five operating modes. These modes are switched successively.
When the nickel-hydrogen battery is attached, the pre-charging is performed at first.
In this mode, it is charged with a constant current (about 0.5A), and the mode is switched to the next mode after 2
minutes.
Since this period is provided to activate the battery, the completion of charging is not detected. Only the battery
protection functions such as overvoltage detection, abnormal temperature detection, etc. are available here.
The next operation is the initial charging as in case of Ni-Cd battery.
Differing from the Ni-Cd battery, the limit voltage of the overvoltage detection is 5.7V and an abnormal temperature
detection function is provided.
The third stage is the quick charging mode, which is equivalent to the quick charging of the Ni-Cd battery.
The phenomenon detection function in this mode and the mode shift due to detection are as follows:
I ) -∆V detection
If battery voltage -∆V (22 to 62mV) is detected, the mode is switched to the trickle charge mode.
II ) Overvoltage detection
Excess of battery voltage over 5.7V is judged to be abnormal, and the mode is switched to the trickle charge
mode.
III ) ∆T detection
If the gradient of temperature rise of the charging battery exceeds 1°C/min., it is judged that the charging is
completed soon and the mode is switched to the sub-charging mode.
IV) Abnormal temperature detection
If the battery temperature reaches 60°C to 65°C during charging, charging is stopped to protect the battery, and
the mode is switched to the trickle charging mode.
V ) Timer operation
When 180 minutes elapse after start of quick charging, the mode is switched to the sub-charging mode.
In the sub-charging mode which is set due to ∆T detection and timer operation in the quick charging mode, constant
current (about 0.5A) charging is performed as with the pre-charging mode.
At this time, the mode is switched by -∆V detection function, overvoltage detection function and abnormal temperature
detection function as in case of quick charging. But the mode is switched to the sub-charging mode by the built-in timer
when one hour elapses after the pre-charging is started.
As with the Ni-Cd battery, the trickle charging current is supplied at the constant voltage and fixed resistance in the
trickle charging mode (fifth stage).
12-3
VL-E610S/VL-E610H
VL-E660S/VL-E96E
VL-E98E