ProMariner ProSport 20 Plus Marine Charger
$199
Key Specs
| output | 20A (3-bank) |
| voltage | 12V |
| battery-types | AGM, Gel, Flooded, Wet |
| weight | 6.6 lbs |
| dimensions | 14.5 x 7.5 x 4.4 in |
| warranty | 3 years |
Pros
- ✓ 3-bank charger — charges up to 3 batteries independently
- ✓ 20A total output (distributed across banks)
- ✓ Fully waterproof — designed for on-board marine installation
- ✓ Digital display shows charge status per bank
Cons
- ✗ Not compatible with lithium batteries
- ✗ Larger form factor than single-bank chargers
Detailed Review
Marine-Grade Build for Permanent Installation
The ProMariner ProSport 20 Plus is designed from the ground up for one specific job: permanent on-board installation on a boat with multiple battery banks. While portable chargers like the NOCO Genius10 serve as capable general-purpose tools, the ProSport 20 is engineered to live inside your vessel year-round, connected to shore power whenever you are docked, maintaining all your batteries simultaneously without any manual intervention.
The fully waterproof and ignition-protected housing meets the demands of the marine environment — spray, condensation, and the occasional splash are not concerns. The charger can be mounted in an engine compartment, under a helm console, or in a bilge-adjacent location without worry. All connections are marine-grade tinned copper, and the AC power cord is long enough to reach most shore power connections from a typical installation point below deck.
Multi-Bank Charging Logic
The three-bank design is the ProSport 20’s defining capability. Each bank operates independently with its own charging output and monitoring circuit. This means your starting battery, bow thruster battery, and house bank are each receiving the correct charge profile for their state of charge — the charger does not simply split power three ways and hope for the best. If your house bank is deeply discharged while your starting battery is full, the charger concentrates more output on the house bank automatically.
The front-panel digital display shows the status of each bank in real time, giving you a clear view of the overall system health when you step aboard. The 20A total output is appropriate for typical three-battery setups where the combined bank capacity is under 400Ah.
Who It’s For
The ProMariner ProSport 20 Plus is the definitive choice for powerboat owners with multiple AGM battery banks who want a set-it-and-forget-it charging solution. It is particularly well-suited to vessels that spend significant time at the dock between outings, where shore power charging is the primary recharge method. Note that this charger is not compatible with lithium batteries — if you have or plan to add LiFePO4 batteries, choose a lithium-compatible multi-bank charger instead.
