Iv) Operation; A) Three Stage Charge Regimen; B) Time-Out Circuit - NewMar PT-24-20W Installation & Operation Manual

IV) OPERATION

A) Three Stage Charge Regimen

The Phase Three Battery Charger features the three stage charge
regimen which is widely recommended by battery manufacturers
for allowing the fastest possible recharge time without loss of
batteries' electrolyte (gel or liquid) which may be caused by
sustained charging at higher voltages.
This three stage regimen is initiated each time AC is first applied,
when drained batteries are most likely to be encountered. (This
also occurs when the reinitialize button on the optional Remote
Panel is activated – see section IV-D – Remote Panel Option). The
regimen proceeds as follows:
1) Bulk Charge – When batteries are significantly discharged the
charger responds initially by delivering a high amount of DC
current, at or near the charger's maximum rated output, in order to
rapidly replenish them. It is during this stage that charging current
is maintained at a high level as battery voltage increases. Bulk
charging continues until battery voltage reached the "charge"
voltage level (where batteries are at about 75-80% of capacity).
A current limit circuit prevents charger overload during this
maximum output stage
2) Absorption Charge – During this second stage of the charge
cycle, battery voltage is maintained at the "charge" voltage level.
Output current begins to taper off as the battery plates become
saturated. Charge voltage is maintained until the current sensing
circuit detects that output current has tapered to about 5-15% of
charger rating*. At this point, the batteries are at about 95% of full
charge and the Phase Three charger switches to the third and final
stage of the charge cycle.
*Note: The absorption phase may also be ended by the time-out
circuit. See section B following for a complete explanation of the
purpose and functioning of the time-out circuit.
3) Float Charge – For extended battery life, the Phase Three
then automatically switches to a lower
This float charge keeps batteries at peak condition without
overcharging. The charger may be left in this stage for months
without attention (though periodic checks of electrolyte level in
flooded batteries is recommended.) FIGURE 3: Typical Charger
Output Graph (into battery without load)
FIGURE 3: Typical Charger Output Graph
(into battery without load)
BULK PHASE
ABSORPTION PHASE
TIME
*Approximately 10 hours maximum at factory setting.
8
P.O. Box 1306, Newport Beach, California 92663 • Phone: 714-751-0488 • Fax: 714-957-1621 • E-Mail: techservice@newmarpower.com
float voltage level.
FLOAT PHASE
VOLTS
www.newmarpower.com

B) Time-Out Circuit

Batteries have a tendency to lose their electrolyte and may be
damaged if they are maintained for long periods of time in the
elevated voltage of the absorption phase. Therefore, the Phase
Three Charger employs a special time-out circuit. This circuit is
initialized each time AC is first applied to the charger (or when the
re-initialize button on the optional remote panel is activated) and
runs for a pre-set interval before forcing the charger to go into the
float (lower voltage) mode. The functioning of the charger during
this interval is as follows:
If the current demand of the batteries/load falls below 5-15 percent
of the charger's output capacity prior to the circuit timing-out, the
charger will automatically switch to the float mode. (For instance,
with model PT-40W, the charger will drop into float mode at
about 2-6 amps output.) If demand rises to about 10-20 percent
of capacity (4-8 amps with PT-40W, for instance), the charger
will return to the elevated output of the absorption phase. This
switching back and forth between modes may occur until the
circuit times-out (8-10 hours after AC is first applied), after which the
charger will remain at float voltage, until the circuit is re-initialized,
either by turning the charger off and then on again or by pressing
the re-initialize button on the remote panel.
Note: The Phase Three Charger is able to deliver its full rated
output current while in float mode.
Installation Note: The time-out circuit of the Phase Three Charger
has been set at about 8-10 hours, which is appropriate for battery
systems within the capacity range specified on the front of the
panel of the charger. If the charger is used with a battery system
with a capacity near (or outside) the upper or lower ranges of
the specified range of the charger, adjustment of the time-out
circuit may be recommended. If the installer wishes to make
this adjustment at the time of installation, the procedure is as
follows (Caution: Ensure AC input has been disconnected before
proceeding):
1) Remove the four screws on the front of the panel and two screws
on each side of the unit.
2) Remove the front cover and locate the potentiometer on the
small "charger function" plug-in printed circuit board which is
labeled "TIMER ADJ."
3) Using a small flat tip screwdriver, turn the potentiometer
clockwise to increase the amount of time the charger remains
in the absorption mode before timing out, or counter clockwise
to decrease the amount of time. The approximate ranges are
illustrated below.
FIGURE 4: Adjusting the Time-out Circuit
�����������
�������
Note: Once the time-out circuit has put the
charger into float mode, the charger will
remain in this mode. Since the Phase Three
Charger is well regulated, it is able to deliver
its full rated output current in this mode and
battery discharge will not occur (provided load
current does not exceed charger rating and
output wiring is properly sized).
�����������