ProMariner ProSportHD 20PLUS On-Board Marine Battery Charger – 20 Amp, 3 Bank – 44021

Keep your boat's batteries charged, maintained, and ready for your next day on the water with the ProMariner ProSportHD 20PLUS On-Board Marine Battery Charger (MFG #44021). Delivering 20 amps of total charging output across three battery banks, this waterproof onboard marine battery charger is designed for automatic charging and maintenance of compatible marine starting, trolling motor, and auxiliary batteries.

The ProSportHD 20PLUS features advanced ProMar Digital Technology and Distributed-On-Demand™ Charging, which automatically directs available charging power to the batteries that need it most. Its digital multi-stage charging system helps provide efficient charging while reducing the need for manual battery maintenance.

Designed for demanding marine environments, the ProSportHD 20PLUS features a heavy-duty tri-surface extruded heat sink, waterproof construction, and an expanded LED display with a charging completion status gauge.

Manufacturer Part #44021 replaces the older ProMariner ProSport Gen3 20 Plus (MFG #43021), making it an updated option for boat owners replacing an existing charger.

Key Features & Benefits

• 20 Amp Total Charging Output: Delivers up to 20 amps of combined charging current across three battery banks.
• 3-Bank Onboard Marine Battery Charger: Charges and maintains three compatible onboard batteries or battery banks.
• ProMar Digital Technology: Microprocessor- and software-controlled charging for precise battery management.
• Distributed-On-Demand™ Charging: Automatically allocates available charging current based on battery demand.
• Digital Multi-Stage Charging: Automatically manages charging and battery maintenance.
• Heavy-Duty Tri-Surface Heat Sink: Upper, lower, and rear-facing cooling surfaces help manage operating temperatures.
• Constant Current Charging Design: Engineered to deliver rated charging current during the appropriate charging stage.
• Expanded LED Display: Provides clear charging information and battery status.
• Charging Completion Gauge: Fuel-gauge-style display helps show charging progress.
• Four-Color Multi-Stage Status Bar: Makes it easier to monitor charging operation.
• System Check OK Indicator: Provides installation and system-status feedback.
• Individual Battery Status Indicators: Helps monitor connected battery banks.
• Battery Type Indication: Displays the selected charging profile.
• Waterproof Marine Construction: Designed for demanding onboard environments.
• Replacement for Part #43021: Updated ProSportHD model replacing the older ProSport Gen3 20 Plus.

Ideal for Marine Battery Charging & Maintenance

The ProMariner ProSportHD 20PLUS 44021 is designed for boat owners who need automatic charging and maintenance across three compatible marine battery banks.

Common applications include:

• Marine starting battery charging
• Trolling motor battery systems
• Auxiliary and house battery maintenance
• Three-bank marine electrical systems
• Fishing boats and recreational powerboats
• Battery maintenance between boating trips
• Seasonal boat storage and winterization

Its three-bank configuration makes it especially useful for boats equipped with multiple batteries that require separate charging connections.

Product Specifications

• Brand: ProMariner
• Product Series: ProSport Heavy Duty
• Model: ProSportHD 20PLUS
• Manufacturer Part Number (MFG #): 44021
• Replaces Manufacturer Part Number: 43021
• Product Type: On-Board Marine Battery Charger
• Total Charging Output: 20 Amps
• Number of Charging Banks: 3
• Charging Technology: ProMar Digital Microprocessor Control
• Charge Distribution: Distributed-On-Demand™
• Charging System: Digital Multi-Stage Charging
• Cooling Design: Heavy-Duty Tri-Surface Extruded Heat Sink
• Status Display: Expanded LED Charging Display
• Charge Completion Indicator: Fuel-Gauge-Style Status Gauge
• Battery Monitoring: Individual Battery Status Indicators
• System Indicator: System Check OK
• Battery Type Indicator: Yes
• Construction: Waterproof Marine Housing
• Quantity Included: 1 Battery Charger

Distributed-On-Demand™ Charging Technology

The ProSportHD 20PLUS uses ProMariner's Distributed-On-Demand™ technology to manage charging power across three battery banks.

Rather than permanently dividing output equally between connected batteries, the charger automatically distributes available charging current based on battery demand.

When one battery requires less charging current, unused capacity can be directed toward other connected batteries that need additional charging.

Important: The ProSportHD 20PLUS provides 20 amps total across three banks, not 20 amps per bank.

Heavy-Duty Tri-Surface Heat Sink Design

The ProSportHD 20PLUS features an upgraded cooling system designed to support consistent charging performance.

Its extruded heat sink includes upper, lower, and rear-facing cooling surfaces to help dissipate heat during operation.

This design helps the charger maintain efficient performance while delivering its rated charging output during the appropriate charging stage.

Digital Multi-Stage Charging & Battery Maintenance

The ProSportHD 20PLUS uses digital charging technology to manage battery charging automatically.

Its multi-stage charging process helps:

• Recharge batteries after use
• Control charging output as battery conditions change
• Complete charging through programmed stages
• Monitor battery charging status
• Support ongoing battery maintenance

Always select the charging profile appropriate for the connected battery chemistry and follow the battery manufacturer's charging recommendations.

Expanded LED Display & Charging Completion Gauge

The ProMariner ProSportHD 20PLUS features an expanded LED display that helps boat owners monitor charging progress and battery status.

Display features include:

• Fuel-gauge-style charging completion indicator
• Four-color multi-stage charging status bar
• Multi-stage charge mode indication
• System Check OK indicator
• Individual battery status indicators
• Selected battery type indication

These features make it easier to monitor the charger and identify potential battery or installation issues.

Waterproof Design for Marine Environments

The ProSportHD 20PLUS is built for onboard marine use with waterproof construction and a heavy-duty cooling design.

Its rugged housing is intended for demanding environments where moisture, vibration, and changing temperatures are common.

Always follow ProMariner's installation instructions, electrical requirements, mounting clearances, and applicable marine electrical standards.

Replaces ProMariner ProSport Gen3 20 Plus – Part #43021

The ProMariner ProSportHD 20PLUS (MFG #44021) replaces the previous ProSport Gen3 20 Plus (MFG #43021).

For boat owners replacing an older ProSport charger, the HD20PLUS offers an updated design with digital charging technology, a tri-surface heat sink, and an expanded LED status display.

Before replacing an existing charger, confirm that the new unit's battery compatibility, electrical requirements, mounting dimensions, and charging configuration meet your boat's needs.

Frequently Asked Questions

What is the ProMariner ProSportHD 20PLUS used for?

The ProSportHD 20PLUS is an onboard marine battery charger designed to automatically charge and maintain three compatible marine battery banks.

Does the ProSportHD 20PLUS provide 20 amps to each battery?

No. The charger provides 20 amps total, distributed across three banks using Distributed-On-Demand™ technology.

Can the ProSportHD 20PLUS charge three batteries simultaneously?

Yes. It is designed to manage charging across three compatible battery banks.

What is the manufacturer part number?

The manufacturer part number is 44021.

What charger does the ProSportHD 20PLUS replace?

The ProSportHD 20PLUS (44021) replaces the older ProMariner ProSport Gen3 20 Plus (43021).

Is the ProSportHD 20PLUS waterproof?

Yes. The charger features waterproof construction designed for marine applications. Follow the manufacturer's mounting and installation requirements.

Can I use this charger during boat winterization?

The charger can support battery charging and maintenance during seasonal storage when installed and operated according to the manufacturer's instructions.

Does the ProSportHD 20PLUS work with AGM batteries?

The charger includes battery type selection. Confirm the supported charging profiles and your battery manufacturer's requirements before connecting AGM batteries.

Can I charge lithium batteries with this charger?

Do not assume lithium compatibility. Only connect lithium batteries if the exact charger model and its manufacturer documentation explicitly support the required lithium battery chemistry.

What is Distributed-On-Demand™ Charging?

Distributed-On-Demand™ automatically allocates available charging current among connected battery banks according to their charging needs.

What's Included

• (1) ProMariner ProSportHD 20PLUS 20 Amp On-Board 3 Bank Marine Battery Charger

Shop marine battery chargers and electrical accessories at Bakes Marine. Find ProMariner onboard battery chargers, marine electrical equipment, and boat maintenance supplies to keep your boat ready for your next adventure.