cen-tech 55 amp battery charger 66722 manual

The Cen-Tech 55 Amp Battery Charger (Model 66722) is a versatile automotive battery charger designed for 12V lead-acid batteries. It features a 55-amp engine start function, 2-amp trickle charge mode, reverse polarity protection, thermal overload protection, and a digital display with voltage and charge status indicators. Below are key sections for safety, features, installation, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Safety Instructions 3. Installation & Setup 4. Specifications 5. Controls and Indicators 6. Charging Procedures 7. Engine Start Function 8. Maintenance & Storage 9. Regulatory Information 10. Troubleshooting

Features at a Glance

Key components: Charger unit, Battery clamps (red/black), AC power cord, Digital display panel, Mode selection switch, Engine start button.

Feature	Description
55-Amp Engine Start	Provides high current for starting vehicles with dead batteries
2-Amp Trickle Charge	Maintains battery charge without overcharging
Digital Display	Shows battery voltage and charging status
Reverse Polarity Protection	Prevents damage from incorrect clamp connections
Thermal Overload Protection	Automatically shuts off if overheated
Heavy-Duty Clamps	Insulated copper jaws for secure connection
Mode Selection Switch	Selects between CHARGE and ENGINE START modes
Power Indicator LED	Illuminates when charger is powered on
Charge Complete Indicator	LED signals when battery is fully charged
Carrying Handle	For easy transport and storage

Safety Instructions

Read all instructions before use. Failure to follow may cause injury or damage.

Use only with 12V lead-acid batteries. Do not use with gel-cell or lithium batteries.
Work in well-ventilated area away from sparks or flames.
Wear safety glasses and gloves when handling batteries.
Ensure charger is unplugged before connecting/disconnecting clamps.
Connect red clamp to positive (+) terminal first, then black to negative (-) or chassis ground.
Do not touch clamps together when charger is powered.

WARNING! Battery gases are explosive. Keep open flames away. Do not charge frozen or damaged batteries.

Installation & Setup

Unpack and inspect contents. Place charger on stable, dry surface.

Position charger: Place near battery but away from engine moving parts.
AC connection: Plug power cord into 120V AC, 60Hz outlet.
Battery connection: Ensure charger is OFF. Connect clamps as described in Safety.
Mode selection: Set switch to CHARGE for normal charging or ENGINE START for jump starting.
Power on: Turn on charger; digital display will illuminate.

CAUTION! Do not place charger directly above battery where dripping acid could damage unit.

Specifications

Model: 66722
Input Voltage: 120V AC, 60Hz
Output Voltage: 12V DC
Charge Rate: 2 Amps (trickle), 55 Amps (engine start)
Battery Compatibility: 12V lead-acid (standard, AGM, deep-cycle)
Display: Digital LCD (voltage, charge status)
Protections: Reverse polarity, thermal overload, short circuit
Cord Length: 6 ft AC cord, 4 ft clamp cables
Dimensions: 10" x 7" x 6" (approx.)
Weight: 8.5 lbs

Controls and Indicators

Front Panel: POWER switch, MODE selector (CHARGE/ENGINE START), Digital display, Power LED (green), Charge Complete LED (red).

Display Readings: Voltage (0.0-15.9V), Charge status (0-100%).

LED Indicators: Green LED = power on. Red LED = charging in progress (flashes when complete).

Mode Selector: CHARGE position for normal/trickle charging. ENGINE START position for jump starting (use only with engine off).

Charging Procedures

For standard 12V battery charging:

Ensure charger is unplugged and OFF.
Connect clamps: Red to positive (+), black to negative (-) or clean chassis ground.
Plug charger into AC outlet.
Set mode switch to CHARGE.
Turn POWER switch ON; green LED illuminates.
Monitor display: Shows battery voltage and charge percentage.
When red LED flashes, battery is fully charged (may take 4-12 hours depending on battery).
Turn POWER OFF, unplug AC cord, disconnect black clamp first, then red.

Tip: For maintenance charging, leave connected in CHARGE mode; charger will automatically switch to float mode.

Engine Start Function

Use only for starting vehicles with discharged batteries.

Connect clamps as in charging procedure (ensure vehicle ignition is OFF).
Set mode switch to ENGINE START.
Turn POWER ON; green LED illuminates.
Wait 30 seconds for battery to receive initial charge.
Start vehicle: Turn ignition key while charger is powered on.
Once engine starts, immediately turn charger POWER OFF.
Disconnect black clamp first, then red clamp from battery.
Allow vehicle to run for 20 minutes to recharge battery.

WARNING! Do not use ENGINE START mode for more than 3 seconds continuously. Allow 3 minutes cooling between attempts. Never touch clamps together in this mode.

Maintenance & Storage

Unplug and clean after each use. Store in dry location.

Cleaning: Wipe with dry cloth only. Do not use liquids or solvents.
Clamp maintenance: Keep jaws clean; remove corrosion with wire brush.
Cord inspection: Check for damage before each use.
Storage: Coil cords neatly; store in original box if possible.
Battery care: Check electrolyte levels before charging (on non-sealed batteries).

CAUTION! Do not store with clamps connected to battery. Keep away from moisture and extreme temperatures.

Regulatory Information

FCC Part 15: Class B digital device; complies with interference limits. UL listed. Copyright © Harbor Freight Tools. For support, visit www.harborfreight.com or contact 1-800-444-3353. This device complies with Part 15 of FCC Rules. Operation subject to conditions: (1) device may not cause harmful interference, (2) device must accept any interference received.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No power indicator	AC outlet dead / cord not plugged	Check outlet with another device; ensure cord fully inserted.
Display shows "0.0"	Clamps not connected / poor connection	Reconnect clamps; clean battery terminals.
Charger overheats	Ventilation blocked / high ambient temp	Move to cooler area; ensure vents unobstructed.
Engine start not working	Battery severely discharged / bad connection	Check connections; try CHARGE mode first for 10 minutes.
Reverse polarity alarm sounds	Clamps reversed	Immediately disconnect and reconnect correctly.
Battery not holding charge	Old/damaged battery	Test battery with load tester; replace if necessary.

Reset: Unplug for 5 minutes to reset protection circuits.

Service: 1-800-444-3353; www.harborfreight.com