Guest ChargePro 28106 6A 12V 1-Bank On-Board Battery Charger

The Guest 28106 ChargePro is the 6-amp, 12-volt, 1-bank on-board marine battery charger - the entry tier of the ChargePro line, designed for boats with a single 12V battery (typical small fishing boats, day-sailers, runabouts, jet skis with auxiliary house batteries). Guest is the marine charger brand owned by Power Products / Marinco - they've been building marine on-board chargers for decades and the ChargePro series is the company's current production line, replacing the older Charge Pro Guest chargers (with the same mounting footprint for drop-in replacement on existing boats).

What it is. An on-board battery charger means the charger lives permanently mounted on the boat, with hardwired DC connections to the battery and a plug-in AC connection to shore power. Plug into shore power at the dock, walk away, the charger handles the rest. When you unplug the AC cord (or when the breaker trips), the charger goes inactive and doesn't drain the battery. This is the right approach for any boat that spends nights at a dock with shore power - it eliminates the manual battery management that used to be a chore for boat owners.

6 amp charge rate. The 6-amp rate is the entry-tier output - appropriate for batteries up to about 60 amp-hours of capacity. For typical small-boat starting batteries (Group 24 / 27 sizes, 60-90 Ah typical), the 6A rate gives you a full charge in 10-12 hours starting from significantly discharged. For bigger battery banks or for boats that come back to the dock badly discharged after a long day, the higher-output ChargePro models (10A, 15A, 20A, 30A) are better matched - the 6A on a 100+ Ah bank takes too long. For small-boat singles, 6A is right.

1 bank means single battery output. The 1-bank designation means the charger has one output circuit feeding one battery (or a battery group connected in parallel to count as one bank). For boats with separate house and starting batteries that need independent charging, the 2-bank or 3-bank ChargePro models are the right call - they isolate each battery on its own charge circuit so the start battery doesn't get over-charged while waiting for the deep-cycle house bank to finish.

Universal 120V / 230V AC input. The ChargePro 28106 accepts both 120V North American and 230V European / international AC input on the same unit - no switch, no jumper, the charger auto-detects and adapts. For boats that travel internationally (sailboats crossing oceans, charter operations between regions, RV / boat snowbirds in different countries), the universal input means the same charger works at any shore power outlet anywhere in the world. For owners who'll only ever plug in at home dock, this is just a convenience - but it's the convenience of not having to think about it.

Multi-stage charging profile. The microprocessor controller runs a multi-stage charge profile: bulk charge (high current to push the battery from discharged toward full), absorption (constant voltage as current tapers, finishing the charge), and float (low maintenance voltage that holds the battery topped up indefinitely without overcharging). This is the right charging behavior for modern marine batteries - older single-stage chargers either undercharge (battery doesn't reach full) or overcharge (gas the battery, shorten its life). The ChargePro's profile keeps the battery healthier over years of use, which matters because marine batteries are expensive and the charger's role in extending their life is meaningful.

Flooded and AGM compatible. The charger's profile handles both flooded lead-acid (the traditional wet-cell battery, with caps you can open and add distilled water to) and AGM (Absorbed Glass Mat - sealed, maintenance-free, more expensive, more capable). The microprocessor adjusts the absorption voltage curve for each chemistry's needs. Lithium batteries are NOT supported - the ChargePro 28106 is a lead-acid charger, and using it on a LiFePO4 or other lithium battery damages the battery and voids the lithium battery's warranty. For lithium installations, use a lithium-specific charger.

Automatically sends charge to batteries that need it most. The charger's controller monitors battery voltage continuously and adjusts the charge output based on the battery's state. For 1-bank installations, this means: when the battery is deeply discharged, full bulk current goes in. as the battery charges, the controller transitions to absorption and float automatically. when the battery is full, the float holds it without overcharging. For owners switching from older fixed-output chargers, the smart behavior is the visible difference - the old charger ran the same current regardless of battery state, and you had to remember to unplug it to avoid overcharging.

IP67 sealed and epoxy-filled. The charger housing is rated IP67 (fully sealed against dust, immersion-protected) and the internal electronics are completely epoxy-filled. Critical for the marine environment where the charger lives in damp lockers, gets sprayed by occasional water intrusion, and operates in the salt-air corrosion conditions that destroy non-marine electronics fast. The epoxy fill means there are no exposed circuits inside the housing - water that does get past the case seal can't short anything out because the electronics are encased in solid epoxy. The housing itself is non-corroding (zinc-plated steel and corrosion-resistant plastic), which keeps the charger looking and functioning right over years of marine use.

Designed for harsh marine and industrial environments. The ChargePro is moisture-rated, salt-spray rated, shock-tested, and vibration-tested. The shock and vibration ratings matter because boats experience constant low-amplitude vibration underway plus occasional high-amplitude shock from waves and wakes - older marine chargers that weren't shock-rated often failed from solder joints fatiguing over time. The ChargePro's design eliminates that failure mode through both the epoxy potting (which damps vibration on internal components) and the heavy-duty mounting design.

Global compliance. UL listed, CE marked, CSA approved, ABYC compliant (American Boat & Yacht Council electrical standards), and California CEC efficient (California Energy Commission energy efficiency requirements). The compliance set means the charger is legal and approved across all major recreational marine markets. ABYC compliance is the most relevant for US recreational boats - if your boat insurance survey scrutinizes the electrical install, ABYC-compliant components don't get flagged.

ConnectCharge plug compatibility. The 28106 supports Marinco's ConnectCharge inlet system - a hardwired AC inlet on the boat (item 150CCI sold separately) that the shore cord plugs into directly. With the ConnectCharge inlet installed, you don't need a removable AC plug and cord assembly inside the boat - the charger is permanently wired to the inlet, and you just plug the shore cord into the inlet from outside. Cleaner install, faster shore-power connection at the dock, and the inlet is rated to the same waterproof standards as the charger itself.

Drop-in replacement for older Guest chargers. The 28106 has the same external dimensions and mounting footprint as the previous Charge Pro Guest 6A 1-bank charger. For owners replacing an older Guest charger, this means the existing mounting holes work and the existing cable runs are the right length - install is mostly a matter of disconnecting the old unit and connecting the new one in its place. Total replacement install is typically 30-60 minutes for a competent boat owner.

Compact 8.9 x 6.4 x 2.4 inches. The compact form factor lets the charger fit in tight battery compartments, under helms, in starboard lockers, and in other typical small-boat mounting locations. At 2.4 inches depth, it's slim enough to mount on bulkheads where deeper chargers wouldn't fit. Plan for 1-2 inches of clearance on all sides for ventilation - the charger generates heat during bulk charging and needs airflow to manage it.

Limited 2-year warranty. Guest backs the ChargePro 28106 with a limited 2-year warranty against manufacturing defects. Reasonable warranty term for an entry-tier marine charger - enough to cover infant-mortality failures (the early failures that come from manufacturing defects) without the longer-warranty premium price of higher-tier marine chargers. Save the receipt and the original packaging if practical for warranty service.