Vectronics VEC-412K - Manual (Page 29)

VEC-412K Owner's Manual Rapid Battery Charger/Conditioner Kit
27
voltage, plus an extra 2-volts to compensate for losses in the charger circuitry,
we will need a power supply capable of supplying 8 Vdc.
Since the cell count is between 1 and 6, Range Switch SW3 is set to the OFF
position. Rotary Switch SW1 is set to position 5 as shown in Table 1 for a 5-cell
battery pack.
We know the battery has a 600-mAh rating. What this means, in theory, is that
the battery will supply 600-mA of current for one hour. Conversely, applying
600-mA of charging current for one hour should fully charge the battery. This is
also theoretical. Charging involves losses, such as heat, and heat is wasted
energy. Charging may require 70 or 80 minutes at a 600 mA charge rate current.
Likewise, in reality a 600-mAh battery may be able to only deliver a maximum
300-mA current over a two-hour span.
The battery fast charge rate is not given on the battery label. To be safe, we will
use the C/2 charge rate, 300 mA. Table 2 shows the closest Charge Rate Current
is 250 mA. Table 3 shows for the C/2 fast charge rate the Time Out safety timer
is 180 minutes, or 3 hours. 3 hours x 250 mA = 750 mAh. 150 mAh should
provide enough margin to fully charge the 600 mAh battery.
At this point we also know our charger power supply must be rated for
something greater than 250 mA.
For the 250-mA charge current, Table 2 shows a jumper must be placed on HD4
pins 1-2, and on HD5 pins 2-3.
For the C/2 fast charge rate, Table 3 shows HD2 has a jumper on A-B, and HD1
has no jumper applied (open).
We also don’t know the maximum discharge rate specified for this battery. Since
a discharge rate equal or less than the battery capacity C ( 600 mA) is
acceptable, either the 120 mA or 240 mA discharge rate may be used. We will
use the 240 mA discharge rate. The HD3 jumper is placed over the 240-mA
position.
The battery label plainly identifies the battery as being a NiCd pack. The
Negative Increment of Voltage Detection for NiCd packs is enabled by placing
the jumper over the ON position of the HD6 header.
Attach the battery to the charger leads. The red charger lead is attached to the
positive ( + ) battery terminal, the black charger lead is attached to the negative (
- ) battery terminal. With the power supply connected, the charger may be
turned on using power switch SW2.
Upon turn on, the red Status LED CR1 will show the current charger activity.
Refer to Table 4 to interpret the LED status indication.