6
Users Manual SMP Service Charger
SMP
is a High Frequency Charger and DC Power Supply developed for service needs as well as for
your electronic laboratory. SMP is a perfect help when servicing of batteries and chargers since it is so
small and handy. This unit is extremely suitable for the purpose of de-sulphating batteries. It can also
be used when checking and adjusting the battery chargers PCB’s voltage levels (not for
microcomputer controlled chargers). It is also useful as an aid to start deeply discharged batteries.
The
SMP
is equipped with an On/Off switch for safe operation and two potentiometer knobs for the
adjustment of Voltage and/or Current levels. In effect voltage and current levels will never increase
above adjusted levels. A display with back-light makes it very easy to read the values even in the
darkest service areas.
Adjustments
:
Are done with knobs market
VOLTAGE
and
CURRENT
as well as the
SET
button. The SMP has to be connected to an electric load to be able to
see any current draw from the display.
Voltage Limit:
Turn the knob marked
VOLTAGE
to the required voltage level.
Current Limit:
Turn the knob marked
CURRENT
to the required current level.
Voltage:
Press the
SET
button to see the adjusted voltage level.
Current:
Press the
SET
button, to see the adjusted current level.
This is a typical example of adjustment when de-sulphating batteries. Typical for a sulphated battery
is that the capacity is low even if the charger shows fully charged. The total charging time normally
tends to be rather short and the specific gravity is lower than for a normally fully charged battery.
The
SMP-charger
can be a very good aid to recondition batteries. A constant low DC-current during
a long period of time is needed (2-14 days). A rule of thumb is that the voltage should not override
2,8V/cell and the current should only be 0,8-1,0% of the battery capacity (Ah/5h). It is essential, not to
increase the current level in the belief to speed up the de-sulphating process. It may only destroy the
battery through over-heating.
Practical example:
Let’s assume that we have a 48 V battery on 500Ah/5h capacity. A suitable
voltage according to above information should be 2,8V/cell x 24 cells =
67,2V. The adjusted current should be 0,8% x 500Ah / 100 = 4, i.e. 4,0A
(0,008 x 500 = 4)
9904111 Issue 4
