ProMariner - Pro IsoCharge 3-Bank - 23125
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The ProMariner ProIsoCharge 180-3 is an advanced digital battery isolator for 12V marine charging systems with one alternator input and three independent battery bank outputs. Unlike a traditional diode-style isolator, the ProIsoCharge design is intended to distribute alternator charging with zero voltage loss, helping battery banks receive full alternator charging voltage without the typical diode drop. Part number 23125 is the 180 amp, 3-bank version for larger marine DC systems with separate starting, house, auxiliary, bow thruster, windlass, or equipment battery banks.
Key Features
- ProMariner part number: 23125
- Model: ProIsoCharge 180-3
- Product type: Advanced digital battery isolator
- System voltage: 12V DC marine electrical systems
- Configuration: 1 alternator input / 3 battery bank outputs
- Maximum output rating: 180 amps DC
- Charging design: Zero-voltage-loss smart isolator
- Control type: Microprocessor-controlled charging distribution
- Priority function: Prioritizes engine start battery charging before bringing auxiliary banks online
- Start battery threshold reference: 13.3V
- Load isolation: Helps isolate high-draw battery bank loads from other banks
- Housing protection: Sealed waterproof housing rated IP66
- Diagnostics: Front-facing LED status indicators for charging, tracking, alternator fault, and over-voltage conditions
- Activation: Ignition-activated operation to reduce parasitic draw when the vessel is off
Product Compatibility
This isolator is intended for 12V marine electrical systems using a single alternator to charge three separate battery banks. Common layouts may include:
- Engine start battery
- House battery bank
- Bow thruster battery bank
- Windlass battery bank
- Auxiliary equipment battery bank
- Electronics or accessory bank
The ProIsoCharge 180-3 is best suited for vessels where battery-bank separation is important, but where the charging system should avoid the voltage drop associated with conventional diode isolators.
Fitment Notice
Confirm the alternator's maximum rated output, system voltage, battery bank count, battery chemistry, cable length, cable gauge, circuit protection, ignition feed, and charging layout before ordering. This unit is for 12V systems and should not be selected for 24V or 32V installations unless the manufacturer documentation for the exact model confirms compatibility.
The isolator rating must meet or exceed the alternator output. Part number 23125 refers to the 180 amp, 3-bank version. The lower-rated 120 amp version is a different model and is commonly referenced as part number 23124.
When This Product Needs Replacement
Replace or upgrade the isolator if the existing charging system undercharges house batteries, causes uneven bank charging, allows one battery bank to drain another, creates excessive voltage drop, or no longer matches the vessel's alternator and battery-bank layout. It may also be used when converting from an older diode isolator to a zero-voltage-loss digital charging isolator.
Common symptoms of a weak or mismatched isolator include low charging voltage at the house bank, batteries that never fully recover underway, excessive heat at terminals, alternator fault warnings, or starting batteries being affected by large auxiliary loads.
Installation Notes
Mount the unit in a dry, accessible, well-ventilated location suitable for marine electrical equipment. Use properly sized marine-grade cable, terminals, fuses or breakers, and strain relief for the alternator and battery-bank circuits. Keep wiring runs as short and direct as practical while maintaining service access and safe routing.
Connect the ignition activation feed as required so the isolator operates only when the engine key is in the run position. After installation, verify alternator output, battery-bank voltage, LED status indicators, terminal temperature, and charging behavior under real operating load.
For high-output alternators, bow thruster banks, windlass banks, lithium battery systems, or complex multi-charger installations, confirm the full charging design before installation. Follow the ProMariner instructions and applicable marine electrical standards.
Alternate/Superseded Part Numbers
- ProMariner: 23125
- Model reference: ProIsoCharge 180-3
- Common description: 180 Amp Advanced Digital Battery Isolator, 1 Alternator / 3 Battery Banks
- Related lower-output model: ProIsoCharge 120 amp version, part number 23124
Parts Desk Insight
The major advantage of the ProIsoCharge style system is eliminating diode voltage loss. That matters on boats where the house bank, thruster bank, or windlass bank is not recovering properly from alternator charging. Before choosing this unit, confirm the alternator's rated output and the number of battery banks so the isolator is sized correctly for the full DC system.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.