A77D/A77DE (Micro Processor Controlled SCR Charger)

The La Marche Model A77 Series Battery Charger is engineered for the demanding requirements of Switchgear, Process Control, Oil Exploration and other DC power applications. Powered by Microprocessor Controlled SCR technology, the A77 Series Battery Charger / Battery Eliminator has ±0.25% DC voltage regulation from no load to full load over the specified input voltage, frequency and ambient temperature ranges. These chargers are available in DC output voltages of 24, 48, 130, and 260 VDC with DC output currents from 6 amps and above. Consult factory for any special input and output requirements not mentioned above. The La Marche A77 charger provides value added features such as AC/DC breakers, easy to read LCD display with text readout alarm LED’s and form “C” alarm contacts. Communication options are available to remotely monitor and control the charger using DNP3, Modbus, IEC 61850 and SNMP protocols. The SNMP option features easier and faster charger setup and configuration using a web browser. Designed to meet NEMA PE5 and UL 1012 safety standards.


A77D/A77DE Data Sheet 

A77D/A77DE Instruction Manual

A77D/A77DE Brochure

Stationary Battery Charger Applications

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• Microprocessor Controlled SCR Technology

• A77D - Filtered

• A77DE - Battery Eliminator

• Automatic AC Voltage Compensation

• AC & DC Surge Protection (MOV)

• AC & DC Breaker

• Temperature Compensation Adjustable (1-5 mV /cell/°C)

• Float / Equalize Mode Switch

• Digital Float and Equalize Adjustments

• Digital Current Limit Adjustment 50 to 110%

• ±0.25% DC Voltage Regulation

• SCR Failure Detection

• Load Sharing

• Master Equalize

• Over Temperature Protection

• LCD Display: DC Voltage and Current, Alarms, Unit Temperatures

• Advanced Data Logging (Micro SD)

• LED Indicators: Float / Equalize, AC Failure, AC ON, Summary Alarm, Charger Failure, Low DC Current, Overload / Current Limit, Low DC Voltage, End of Discharge, High DC Voltage, High DC Voltage Shutdown, Positive & Negative Ground Detection

• Remote Annunciation Form “C” Contacts: AC Failure, Summary Alarm (See Optional Accessories For Additional Alarm Contacts)

• Alarms Latching / Non-Latching

• Equalize Timer - adjustable from 1-255 hours with with five selectable modes of operation (manual, automatic every 7, 14 or 30 days and equalize after sensing a low DC voltage)

• UL 1012, CUL & IBC

• 5 Year Warranty

• 2 - Pole High Interrupting Capacity AC Breaker* 65KAIC @ 240 VAC / 35KAIC @ 480 VAC

• 2 - Pole High Interrupting Capacity AC Breaker* 100KAIC @ 240 VAC / 65KAIC @ 480 VAC / 25KAIC @ 600 VAC

• 3 - Pole High Interrupting Capacity AC Breaker* 65KAIC @ 240 VAC / 35KAIC @ 480 VAC

• 3 - Pole High Interrupting Capacity AC Breaker* 100KAIC @ 240 VAC / 65KAIC @ 480 VAC / 25KAIC @ 600 VAC * Only available for units with current draws above 8 amps

• AC Breaker Trip on HVSD

• Adjustable Ground Detection Sensitivity

• AC Voltage & Current Metering (1%)

• Special 30mV Filtering

• Equalize Fan Control Relay

• Reverse Polarity Protection & LED

• Copper Ground Bus Bar

• Lightning Arrestor

• Blocking Diode

• External Temperature Probe 24ft

• External Temperature Probe 100ft

• I.D. Tags - White text on black background

• I.D. Tags - Black text on white background

• Heat Shrink Wire Markers with Electrical Schematic

• Discrete Alarm Relays: Positive Ground, Negative Ground, High DC Volts, Charger Failure,  Low DC Volts, Low DC Amps, Battery End of Discharge, High Voltage Shutdown

• 12 Pulse Rectification

• 5% THD

• Zero Center Ammeter

• Hydrogen Det. HUB, Alarm Interface & Sensor

• Hydrogen Det. HUB, Alarm Interface

• Electrolyte Level HUB, Alarm Interface & Sensor

• IBC Certification Label (consult factory for Anchor Kits)

• IEC 61850 Ethernet

• DNP 3.0 Communications RS232/RS485/Ethernet

• Modbus Communications RS232/RS485/Ethernet

• Modbus RTU RS232/RS485

• SNMP & Web Browser (Ethernet)


AC Input Operating Range Voltage

Voltage range: +10, -12% from nominal

Frequency range: 60 Hz ±5% (50Hz Consult Factory)

Single Phase Voltages

120, 208, 240, 480 or 600 VAC (Tap selectable 120/208/240 on units up to 25 amp output. All other units must specify single input voltage). Consult factory for other voltages.

Three Phase Voltages

208, 240, 480 or 600 VAC

Consult factory for other voltages

DC Output

24, 48, 130, 260 VDC

6 to 500 amps


Single Phase >85%

Three Phase >90%

DC Voltage Regulation Steady State

± 0.25% of setting from no load to full load over the specified input voltage, frequency and ambient temperature ranges.

Data Logging

A77 Battery Charger is equipped with data logging capability on an internal Micro-SD Card. It logs and stores data of Event-Driven and Time-Interval-Driven Events. The charger’s data-log file does not need proprietary software to examine the data; it could be viewed and easily formatted with many popular spreadsheets programs.

Dynamic Response (On Battery)

Voltage transient <±5% over a step change in the load from 20% to 100%

Recovery Time <200mS

Audible Noise

Less than 65dBA at any point 5 feet from any vertical surface of the unit.

Load Sharing

Identical La Marche A77 units, when connected in parallel, are capable of sharing DC load within ±5% for individual unit outputs greater than 5% of the rated output.

Remote Monitoring

Form “C” Alarm Contacts

With optional Communication Card: Connect to SCADA System, Web Monitoring, Alarm / Notification Email

Current Walk-in

The output current will gradually increase after the charger is turned on, eliminating surges and overshoots.

Current Limit

Electronic Current Limiting Control Circuitry provides a digitally adjustable limit from 50 to 110% of the rated output current of the charger, factory set at 110%.

AC Breaker

Single Phase units are equipped with a 2-pole circuit breaker

Three Phase units are equipped with a 3-pole circuit breaker

DC Breaker

Standard units are equipped with a 2-pole circuit breaker

Operating Temperature

0 to 50C (32 to 122⁰F)

Storage Temperature

-40 to 85⁰C (-40 to 185⁰F)

Relative Humidity

0 to 95% (non-condensing)


Convection Cooled

NEMA Type 1

Consult factory for other type enclosures


Floor, wall, or rack mounting is available


Pretreated with a seven stage iron phosphate wash, sealer and deionized rinse. Then coated with an environmentally safe and durable ANSI 61 gray Polyester TGIC Minite powder finish


ABS, UL/CUL 1012, EN 55011, NEMA PE5, FCC Part 15, IEEE/ ANSI C37.90.1, IEC 60255-22-3, IEC 61000-4, IBC


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