Efficient 110VAC to 12VDC converter with 3-stage smart charging. Compatible with Lithium, AGM, and Lead Acid batteries. 910W continuous output.
The PowerMax PM3-65A is a versatile AC to DC converter and battery charger that converts 110VAC shore power or grid power into clean, regulated 12VDC power for charging batteries and powering 12-volt equipment. With a solid 65-amp continuous output (910 watts), this converter provides an excellent balance of power and efficiency for medium-sized battery banks while simultaneously powering all your 12V devices.
Featuring advanced 3-stage smart charging technology, the PM3-65A automatically adjusts its charging profile to match your battery's needs: bulk charging at 14.6V for rapid recharge, normal charging at 13.6V for safe completion, and float charging at 13.2V for long-term maintenance. The unit also offers a fixed voltage mode with adjustable output from 13.0V to 16.5V, making it compatible with ALL battery types including LiFePO4 lithium, AGM, gel cell, and traditional lead acid batteries.
As a direct replacement for WFCO WF-9865 converters, the PM3-65A installs easily in RVs, boats, off-grid solar systems, automotive applications, and anywhere reliable 12V power is needed. Its efficient switch-mode design delivers over 85% efficiency with minimal heat generation, while built-in protection against reverse polarity, overload, and thermal issues ensures safe, reliable operation for years to come.
910W continuous power - charges 130Ah battery in 2 hours, 260Ah bank in 4 hours
Automatic charging profile: 14.6V Bulk, 13.6V Normal, 13.2V Float for optimal battery health
Fixed mode with 13.0V-16.5V adjustment - perfect for lithium batteries and custom applications
Works with Lithium LiFePO4, AGM, Gel Cell, Flooded Lead Acid - all battery types supported
Stage 1 - Bulk Charging (14.6V): When your battery is depleted (below 80% state of charge), the PM3-65A delivers maximum current at 14.6 volts to rapidly restore capacity. This "boost" mode brings batteries back to life quickly after heavy discharge. The converter stays in bulk mode as long as the battery can accept the full 65 amps. Stage 2 - Normal Charging (13.6V): Once the battery reaches approximately 80% charge and can no longer accept full current, voltage drops to 13.6V for safe, controlled charging to 100% capacity. This absorption phase ensures batteries are fully charged without overcharging damage. The PM3-65A simultaneously powers all your 12V devices during this stage. Stage 3 - Float/Storage (13.2V): After batteries reach full charge, the converter automatically switches to 13.2V float mode to maintain charge without overcharging. This trickle charge keeps batteries fresh during storage or light use, preventing sulfation and extending battery life. Perfect for RVs plugged in at home between trips. Automatic Mode Switching: The PM3-65A constantly monitors battery voltage and load conditions, automatically transitioning between charging stages as needed. When you turn on appliances that draw power, the converter instantly provides current while adjusting the charging profile. This intelligent system works 24/7 with zero user intervention required.
RVs & Travel Trailers: Direct replacement for WFCO WF-9865 converters. Powers all 12V lighting, water pumps, slide-outs, awnings, and electronics while rapidly charging house battery banks. Perfect for mid-sized travel trailers and Class C motorhomes with 150-300Ah battery capacity. Off-Grid Cabins & Solar Systems: Converts AC power from generators or grid-tied inverters into clean 12VDC for battery charging. Works alongside solar charge controllers for faster battery recovery during low-sun periods or high-demand situations. Marine Applications: Charges deep-cycle marine batteries when connected to shore power at the marina. Powers 12V electronics, navigation equipment, bilge pumps, and cabin lighting while keeping batteries topped off. Automotive & Performance: Powers car audio systems, emergency vehicle equipment, and mobile workshops. Fast charging between uses means less downtime and more performance. Emergency Backup Power: Maintains battery banks for backup power systems, communications equipment, and critical infrastructure. Float mode keeps batteries ready for instant use during power outages. LiFePO4 Lithium Battery Systems: Adjustable voltage mode (13.0V-16.5V) allows precise matching to lithium battery specifications. Set to 14.4V or 14.6V for optimal lithium charging without battery management system conflict. Telecommunications & Remote Sites: Reliable power for radio equipment, cellular sites, internet equipment, and remote monitoring systems. Converts generator power into clean DC for sensitive electronics.
Certified Electrician Installation Required • Professional Installation Mandatory: All PowerMax converters must be installed by a certified electrician per NEC code requirements. • Ventilation Critical: Minimum 1" free air space required at each end for proper cooling. Do NOT install in zero-clearance compartments. • AC Circuit Requirements: Connect to dedicated 15-amp 120VAC circuit within 36" of converter. Do NOT share circuit with high-draw appliances. • Wire Sizing: Use minimum 8 AWG copper wire for DC output connections. Larger wire recommended for long runs to minimize voltage drop. • Battery Disconnect: ALWAYS disconnect battery positive (+) terminal BEFORE connecting converter to prevent sparks and reversed polarity damage. • Never in Flammable Storage: DO NOT install in compartments containing batteries, gasoline, propane, or other flammable materials. • Proper Grounding: Connect 8 AWG ground wire from chassis to converter bonding lug for safety and code compliance. • Terminal Torque: Tighten all DC connections securely - loose connections cause overheating and fire risk.
In The Box: • PM3-65A Converter/Charger Unit • Built-in 36" AC Power Cord • Chassis Bonding Lug (Pre-installed) • Mounting Flanges with Holes • Reversed-Battery Fuses (Internal) • Owner's Manual with Wiring Diagrams • Warranty Documentation NOT Included (Required for Installation): • 8 AWG or larger DC wiring • Wire terminals/lugs for DC connections • Mounting screws/bolts • 8 AWG chassis ground wire • Professional electrician installation service
Compare the PM3-65A with other models in the PM3 Series to find the right converter for your power requirements.
Estimated time to charge from 50% to 100% state of charge (bulk + absorption phases). Actual times vary based on battery type, temperature, and condition.
Note: Charging times assume battery can accept full 65A charge rate. Absorption phase may take additional 30-60 minutes to reach 100% capacity. Lithium batteries typically charge faster than lead acid due to higher charge acceptance rates.
Why the PM3-65A is Perfect for Lithium: The PowerMax PM3-65A offers adjustable voltage output (13.0V-16.5V) that allows precise matching to your lithium battery manufacturer's specifications. Most LiFePO4 batteries charge optimally at 14.4V to 14.6V, and the PM3-65A can deliver exactly that voltage continuously. Setting Fixed Voltage Mode for Lithium: 1. With the converter unplugged, locate the two switches on the side of the unit 2. Move Switch A (right) to "Fixed Voltage" position 3. Plug the converter into 120VAC power 4. Using a voltmeter on the DC output terminals, adjust Switch B (up/down dial) until you reach your desired voltage 5. Common lithium settings: 14.4V (most conservative), 14.6V (faster charging), or per your battery manufacturer's specs 6. Once set, the converter will maintain this exact voltage every time it's powered on Important Lithium Considerations: • Consult your battery manufacturer's charging specifications before setting voltage • Battle Born recommends 14.4V | RELiON recommends 14.6V | Lithionics recommends 14.4V • Ensure your lithium battery has a proper Battery Management System (BMS) that will disconnect charging if cells become imbalanced • The PM3-65A's 65-amp output is safe for most lithium banks 130Ah and larger (0.5C charge rate or less) • Lithium batteries charge much faster than lead acid - expect 50% faster charging times • Monitor first few charge cycles to ensure battery BMS and converter work together properly Returning to 3-Stage Mode: To switch back to standard 3-stage lead acid charging, power down the unit, move Switch A back to "Three Stage" position, power up, and use Switch B to adjust voltage to 14.6V with a voltmeter.
Product Documentation: Download PM3 Series Owner's Manual (PDF) Download PM3 Series Specification Sheet (PDF) Lithium Battery Resources: Using PowerMax with Battle Born Batteries (External Link) Warranty Information: 2-Year Limited Manufacturer's Warranty Covers defects in materials and workmanship under normal use No forms required - call tech support for rapid replacement Replacement unit shipped promptly upon defect confirmation Return shipping arranged for defective unit Company Website: www.powermaxconverters.com PowerMax Converters 5107 Lena Road, Suite 108 Bradenton, FL 34211
A: The PM3-65A and PM3-55A are very similar converters with the primary difference being output current capacity. The PM3-65A delivers 65 amps (910 watts) while the PM3-55A delivers 55 amps (800 watts) - a difference of 10 amps or 110 watts. Both models have identical physical dimensions (7.8" x 9.5" x 3.5"), same weight (7 lbs), same efficiency (>85%), and identical features (3-stage charging, adjustable fixed voltage mode, same protection circuitry). Choose the PM3-55A if: Your battery bank is 100-200Ah and you have moderate 12V loads (under 40 amps). The 55A output provides sufficient charging current for this size system. Choose the PM3-65A if: Your battery bank is 150-260Ah, or you frequently run higher 12V loads (40-50 amps) that would push the PM3-55A near its limit. The extra 10 amps provides more headroom for simultaneous charging and loads. Cost consideration: The PM3-65A typically costs $20-30 more than the PM3-55A. For this modest price difference, many RV owners choose the PM3-65A for the extra capacity "just in case" future needs grow. Both converters share the same AC circuit requirements (15 amps), so electrical installation is identical. If your battery bank is right at the border (around 200Ah), the PM3-65A is the better choice for faster charging and more headroom for loads.
A: The PM3-65A is a direct drop-in replacement for the WFCO WF-9865 with several meaningful improvements. Both are 65-amp converters with similar physical dimensions, but the PowerMax offers: (1) Adjustable voltage output - The PM3-65A has a fixed voltage mode with adjustable output from 13.0V to 16.5V, making it compatible with lithium batteries. The WFCO is designed primarily for lead acid batteries only. (2) 3-stage smart charging - More sophisticated charging algorithm (Bulk/Normal/Float) that extends battery life compared to WFCO's charging profile. (3) Better fan control - Temperature-controlled proportional fan runs quietly during light loads, whereas some WFCO models run fans at constant speed regardless of load. (4) Improved reliability - PowerMax converters have a strong reputation for long-term reliability with fewer warranty claims than some WFCO models. (5) Equal efficiency - Both achieve >85% efficiency, so power consumption is comparable. The PM3-65A uses the same mounting pattern and wire connections as the WF-9865, making upgrades straightforward. Installation typically takes 30-60 minutes for an RV technician. Many RV owners report improved charging performance, quieter operation, and better lithium battery compatibility after upgrading from WFCO to PowerMax. The PM3-65A is particularly popular among RV owners who have upgraded to lithium batteries and need a converter that can properly charge them.
A: Whether 65 amps is sufficient depends on your battery bank size and typical usage patterns. Here's how to evaluate: Battery Bank Sizing Guidelines: For lead acid batteries, a safe charging rate is 10-25% of battery capacity (C-rate). A 65A converter can safely charge: (1) 260Ah minimum (65A = 25% charge rate), (2) 390Ah typical (65A = 17% charge rate), (3) 650Ah maximum conservative (65A = 10% charge rate). For lithium batteries that accept higher charge rates (0.5C to 1C), 65 amps is suitable for 130Ah to 260Ah banks. Typical RV Scenarios: (1) Small-Medium Travel Trailers (200-300Ah lead acid): 65A is perfect - provides good charging speed without overwhelming batteries. (2) Large Travel Trailers or Small Motorhomes (300-400Ah): 65A works but charges slower. Consider PM3-75A or PM3-100A for faster recovery. (3) Lithium Systems (100-200Ah): 65A is ideal - provides 0.3C to 0.65C charge rate which lithium batteries handle easily. Load Considerations: Remember the converter must power both charging AND your 12V loads simultaneously. If you regularly run 30-40 amps of loads while charging, only 25-35 amps goes to batteries. This is fine for smaller banks but larger banks will charge slower. Bottom line: 65 amps is the "sweet spot" for many mid-sized RVs and provides excellent value. It's significantly more powerful than 45A or 55A models but doesn't require the heavier AC circuit that 75A+ models need.
A: Yes, absolutely - the PM3-65A is designed to simultaneously power 12V loads (like refrigerators) while charging batteries. This is one of the primary functions of RV converters. Here's how it works: The PM3-65A delivers 65 amps total output, which is automatically distributed between (1) charging your batteries and (2) powering your 12V loads. Example scenario with a 12V refrigerator: A typical 12V RV refrigerator draws 4-8 amps when the compressor is running (cycling on/off). Let's say your fridge averages 6 amps, you have lights and fans using 8 amps, and your water pump occasionally runs (10 amps peak). Total loads: 6A + 8A = 14A continuous, plus 10A pump when running = 24A peak. The PM3-65A delivers: 65A total - 24A loads = 41A remaining for battery charging (during peak loads), or 65A - 14A = 51A for charging during normal operation. Your batteries charge at 41-51 amps while the refrigerator runs continuously. Important points: (1) The converter prioritizes loads over charging - your refrigerator always gets power first, (2) Battery charging rate automatically adjusts based on load demand, (3) If total demand exceeds 65A, the batteries supplement the difference (but this rarely happens with typical RV loads). Real-world performance: RV owners report excellent results running residential refrigerators (12-15A draw) on the PM3-65A while still charging batteries at 50A+. The converter handles the load easily without overheating or triggering protections. Just ensure proper ventilation and your batteries are large enough to handle brief high-load periods when converter output is fully utilized.
A: Fixed voltage mode serves several important purposes beyond the standard 3-stage charging that most RV owners use. Here are the main reasons to use fixed voltage mode: 1. Lithium Battery Charging: This is the most common reason. LiFePO4 lithium batteries typically require 14.4V-14.6V continuous charging (check your battery specs). The PM3-65A's 3-stage mode charges at 14.6V/13.6V/13.2V, which works but isn't ideal for lithium. Setting fixed voltage to exactly 14.4V (or 14.6V) provides optimal lithium charging without the voltage drops of 3-stage mode. Your lithium BMS handles charge termination, so you don't need the converter's multi-stage profile. 2. Powering 12V Equipment: Some sensitive 12V equipment requires a stable, constant voltage (like 13.8V) for proper operation. Fixed mode provides rock-solid voltage without the fluctuations of 3-stage charging. This is important for: radio equipment, telecommunications gear, industrial controls, or medical equipment. 3. Custom Battery Types: Some specialty batteries (certain gel cells, calcium batteries, or custom lithium chemistries) have specific voltage requirements that don't match the 14.6V/13.6V/13.2V profile. Fixed mode lets you match manufacturer specs exactly. 4. Temperature Compensation: In extreme cold environments, some users manually adjust voltage higher (14.8V-15V) to improve charging efficiency. In hot climates, lowering to 13.8V-14.0V reduces gassing and water loss. 5. Extended Storage: For long-term RV storage (months), some owners set voltage to 13.5V-13.8V to maintain batteries without overcharging. This is lower than the normal 13.6V float voltage for gentler long-term maintenance. Bottom line: Most RV owners with standard lead acid or AGM batteries never need fixed voltage mode - 3-stage works perfectly. But for lithium batteries or specialized applications, fixed voltage mode is invaluable and sets PowerMax apart from converters that lack this feature.
A: If your PM3-65A is cycling on and off repeatedly (turning on for a few seconds, then shutting down, then restarting), this indicates a protection circuit is activating. Here's how to diagnose and fix the problem: Most Common Cause - Overload or Short Circuit: The converter detects excessive current draw (over 65A) or a short circuit and shuts down to protect itself. Check for: (1) Shorted wiring - inspect all DC connections for bare wires touching metal, damaged insulation, or pinched wires, (2) Failed 12V device - disconnect all 12V loads one by one to identify which device is causing the overload, (3) Battery voltage sensor problem - weak battery connections can cause voltage sensing errors. Second Common Cause - Thermal Overload: The converter is overheating and thermal protection is shutting it down. After cooling briefly, it tries to restart. Check for: (1) Blocked airflow - ensure 1" minimum clearance on both ends for cooling, (2) Excessive ambient temperature - converter installed in hot compartment (engine bay, near water heater), (3) Fan failure - listen for fan operation during high loads, (4) Dust buildup - clean ventilation openings with compressed air. Other Possible Causes: (1) AC input problems: Weak AC power supply (low voltage, loose connections, undersized circuit) causes converter to shut down and restart, (2) Reversed battery connections: Internal fuses have blown - converter attempts to start but fails immediately, (3) Internal component failure: Rare, but possible - converter may need warranty service. Troubleshooting steps: (1) Disconnect ALL loads and battery from converter DC terminals, (2) Power on converter and measure output voltage (should read 14.6V with no load), (3) If voltage is stable with no load, gradually reconnect loads to identify problem device, (4) If cycling continues with no load, check for overheating, blocked airflow, or contact PowerMax tech support for warranty service.