Sony BC-1WD Service Manual page 6

Table of Contents
Overview ......................................................... 14
Locations and Functions of Parts ................ 16
Charging ......................................................... 17
Specifications ................................................. 19
14
Overview
The BC-1WD/1WDCE is a battery charger capable of
continuous charging, into which any four NP-1/1A/1B
battery packs can be inserted simultaneously.
The BC-1WD/1WDCE is equipped with the following
features.
Features
Up to four battery packs can be inserted
Up to four NP-1/1A/1B battery packs can be inserted
and charged in order. More than four battery packs
can be charged continuously by removing the fully
charged battery packs and replacing them with
discharged ones.
Compact and lightweight
The BC-1WD/1WDCE is compact, lightweight, and
easy to carry.
Automatic refresh function
If a battery pack with remaining capacity is charged
repeatedly, the storage capacity of the battery may be
reduced due to memory effect (phenomena by which
the remaining battery capacity is memorized). To
prevent against this memory effect, an "auto refresh
function" is provided to fully discharge a battery pack
automatically before charging.
Diagnostics functions
The BC-1WD/1WDCE has functions to check for
abnormalities in the connected battery packs. A red
and green lamp will alternately flash when a battery
pack cannot be normally charged indicating an
abnormal condition.
Life judgement function
The available capacity of the battery is indicated. This
criterion is used to determine the life of the battery
pack.
Fully charged battery skip function
When a fully charged battery pack is inserted into the
BC-1WD/1WDCE, the battery is neither charged nor
discharged, and the indication "Charging End" will
appear on the display.
Charging System
The BC-1WD/1WDCE begins discharging once the
POWER switch is turned ON. It continues to give a
booster charge until the voltage drop of –DV (see the
figures below), which occurs near the end of charging,
is detected. Trickle charging (charging at a slow rate
to normally maintain the battery in a fully charged
condition and to protect against self discharge) will be
done after all of the inserted batteries have been
charged. Trickle charging automatically stops after 24
hours of continuation. Further, the charging status
varies, as seen in the diagrams below, according to
whether you are in the auto refresh mode or the refresh
cancellation mode.
Charging in auto refresh mode
Battery voltage
V, I
Booster charge current
Discharge stop voltage
0
Rest
Discharge current
Booster charge
POWER
Start of discharge in progress
switch →ON
Check that the REFRESH
OFF button is off.
Charging in refresh cancellation mode
Battery voltage
V, I Battery charge current
0
Booster charge
Near
in progress Trickle charge
POWER
end
switch →ON
End of booster
Press the REFRESH OFF
charging
button and it will light
V : Battery voltage
I : Charging current
∆V
Trickle charge current
Time
Near
Trickle charge
end
End of booster
charging
V : Battery voltage
I : Charging current
∆V
Trickle charge current
Time
15