Schumacher Battery Charger Manual SE 4020

The Schumacher SE 4020 is a fully automatic battery charger and maintainer designed for 6V and 12V lead-acid batteries, including standard, AGM, and gel cell types. It features microprocessor-controlled charging, automatic voltage detection, float mode monitoring, reverse hook-up protection, and a multi-stage charging process for optimal battery health and longevity. Below are key sections for safety, features, operation, maintenance, and troubleshooting.

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

Features at a Glance

Key components: Microprocessor control unit, Charging cables with clamps, AC power cord, LED status indicators, Mode selection button.

Feature	Description
Automatic Voltage Detection	Detects 6V or 12V battery automatically
Multi-Stage Charging	Bulk, Absorption, Float modes for optimal charging
Battery Type Support	Standard, AGM, Gel Cell lead-acid batteries
Float Mode Monitor	Maintains battery at full charge without overcharging
Reverse Polarity Protection	Prevents damage if clamps are connected incorrectly
Spark-Proof Technology	Safe connection to battery terminals
LED Status Indicators	Shows charging, maintenance, and fault conditions
Fully Automatic Operation	No manual adjustments needed after connection
Compact Design	Portable for garage, workshop, or storage use
Overcharge Protection	Automatically switches to float mode when full

Safety Instructions

Read all instructions before use. Charger produces hydrogen gas—keep away from flames and sparks.

Use in well-ventilated area only.
Wear eye protection when working near batteries.
Do not charge frozen or damaged batteries.
Ensure charger is unplugged before connecting/disconnecting clamps.
Connect to battery before plugging into AC outlet.

WARNING! Risk of explosive gases. Do not smoke or use near open flame. Battery acid can cause severe burns.

Installation & Setup

Unpack charger and inspect for damage. Ensure work area is dry and well-ventilated.

Prepare battery: Clean terminals if corroded. Remove battery caps if applicable (except sealed batteries).
Connect clamps: RED clamp to POSITIVE (+) terminal. BLACK clamp to NEGATIVE (-) terminal or grounded metal.
Plug in charger: Insert AC plug into 120V, 60Hz outlet.
Automatic start: Charger will detect voltage and begin charging automatically.

CAUTION! Never connect clamps in reverse order. Ensure firm contact with terminals.

Specifications

Model: SE 4020
Input Voltage: 120V AC, 60Hz
Output Voltage: 6V / 12V automatic detection
Charging Current: 2A (trickle), 10A (standard)
Battery Types: Lead-Acid (Standard, AGM, Gel Cell)
Charging Stages: 3-stage (Bulk, Absorption, Float)
Protections: Reverse polarity, spark-proof, overcharge
Indicators: LED (Power, Charging, Maintenance, Fault)
Cable Length: 40-inch battery clamps, 6-foot AC cord
Operating Temperature: 32°F to 104°F (0°C to 40°C)

Controls and Indicators

Front Panel: POWER LED (green), CHARGING LED (red), MAINTENANCE LED (green), FAULT LED (red).

LED Status Guide:

POWER (Green): AC power connected
CHARGING (Red): Actively charging battery
MAINTENANCE (Green): Battery fully charged, maintaining float voltage
FAULT (Red): Reverse connection, bad battery, or other error

Operation: Fully automatic—no buttons to press after connection. For maintenance mode, leave connected after full charge.

Charging Procedure

Follow these steps for safe and effective charging.

Ensure charger is unplugged from AC outlet.
Connect RED clamp to battery POSITIVE (+) terminal.
Connect BLACK clamp to battery NEGATIVE (-) terminal or clean chassis ground.
Plug charger into 120V AC outlet.
POWER LED will light green; CHARGING LED will light red.
Charger automatically progresses through bulk, absorption, and float stages.
When MAINTENANCE LED lights green, battery is fully charged.
To disconnect: Unplug AC cord, then remove BLACK clamp, then RED clamp.

Tip: For deeply discharged batteries, charger may take several hours to reach full charge.

Maintenance Mode

The SE 4020 can be left connected to maintain battery charge indefinitely.

After full charge (MAINTENANCE LED green), charger switches to float mode.
Float mode monitors battery voltage and provides small charge pulses as needed.
Ideal for seasonal vehicles, boats, motorcycles, or stored equipment.
Safe for long-term connection—prevents sulfation and discharge.

Note: Maintenance mode works only with healthy batteries. Do not use on damaged or leaking batteries.

Care & Storage

Unplug and disconnect from battery before cleaning. Store in dry, cool location.

Wipe exterior with dry cloth only.
Inspect cables regularly for cracks or exposed wire.
Keep clamps clean and free of corrosion.
Store in original box or protective case when not in use.

CAUTION! Do not immerse in water or use solvents. Keep away from children and pets.

Regulatory Information

FCC Part 15: Class B digital device; complies with limits for residential use. UL and cUL listed. Copyright © Schumacher Electric Corporation. All trademarks property of their respective owners. For technical support, visit www.schumacherelectric.com or call 1-800-621-5485.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No LED lights	No AC power	Check outlet; ensure plug is fully inserted; try different outlet.
FAULT LED lit	Reverse connection / bad battery	Disconnect and reconnect clamps correctly; test battery voltage.
CHARGING LED blinks	Battery voltage too low	Allow more time; if voltage below 3V, battery may be unusable.
Battery not holding charge	Old or damaged battery	Test battery with load tester; replace if necessary.
Charger gets warm	Normal during bulk charge	Ensure ventilation; if excessively hot, unplug and contact support.
Clamps sparking	Loose connection	Ensure clamps have firm contact; connect negative clamp first.

Reset: Unplug charger, disconnect clamps, wait 30 seconds, then reconnect.

Service: 1-800-621-5485; www.schumacherelectric.com