Powerful 110VAC to 12VDC converter with 3-stage smart charging. Compatible with Lithium, AGM, and Lead Acid batteries. 1460W continuous output.
The PowerMax PM3-100A is a high-performance 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 massive 100-amp continuous output (1460 watts), this converter can rapidly charge large battery banks while simultaneously powering all your 12V devices.
Featuring advanced 3-stage smart charging technology, the PM3-100A 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-68100 converters, the PM3-100A 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 93% efficiency with minimal heat generation, while built-in protection against reverse polarity, overload, and thermal issues ensures safe, reliable operation for years to come.
1460W continuous power - charges 100Ah battery in 1 hour, 200Ah bank in 2 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 PM3-100A 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 100 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 PM3-100A 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 PM3-100A 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 & Motorhomes: Direct replacement for WFCO WF-68100 converters. Powers all 12V lighting, water pumps, slide-outs, awnings, and electronics while rapidly charging house battery banks. Perfect for large Class A motorhomes with 400Ah+ battery capacity. Off-Grid 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, bowfishing lights, 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. Communications & Off-Grid Cabins: Reliable power for ham radio stations, cellular boosters, internet equipment, and small cabin electrical systems. Converts noisy 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: • PM3-100A 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 PM3-100A 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 100A 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 PM3-100A is Perfect for Lithium: The PowerMax PM3-100A 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 PM3-100A 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 PM3-100A's 100-amp output is safe for most lithium banks 200Ah 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 PM3-100A is a direct drop-in replacement for the WFCO WF-68100 with several significant improvements. Both are 100-amp converters with the same physical dimensions and mounting footprint, but the PowerMax offers: (1) Adjustable voltage output - The PM3-100A has a fixed voltage mode with adjustable output from 13.0V to 16.5V, making it compatible with lithium batteries. The WFCO is fixed at lead acid voltages only. (2) Better efficiency - The PM3-100A achieves >93% efficiency compared to WFCO's ~85%, meaning less AC power consumption and less heat generation. (3) Quieter operation - Temperature-controlled proportional fan runs quietly during light loads, while WFCO fans run at full speed constantly. (4) Superior surge capacity - The PM3-100A can handle momentary peak loads better than WFCO converters. (5) 3-stage smart charging - More sophisticated charging algorithm extends battery life. The PM3-100A uses the same wiring connections and mounts in the same location, making upgrades quick and easy. Many RV owners report dramatic improvements in battery charging performance and reduced fan noise after upgrading from WFCO to PowerMax.
A: Yes, absolutely - that's one of the primary design features of the PM3-100A. The converter delivers 100 amps continuously, which can be distributed between battery charging and powering 12V loads simultaneously. For example, if you're running 30 amps of 12V lighting, water pump, and electronics, the converter will supply those 30 amps to your loads while still delivering 70 amps to charge your batteries. The PM3-100A acts as both a power supply and a battery charger at the same time. This is how RV electrical systems work when plugged into shore power - the converter maintains a constant 12V supply for all your equipment while keeping batteries charged. The converter automatically adjusts its charging voltage based on load conditions, seamlessly transitioning between the 3 charging stages as needed. This means you never have to worry about disconnecting loads or turning off the charger - it all happens automatically. The only limitation is total current: if you're drawing more than 100 amps combined (loads + charging), the converter will current-limit and charging rate will slow down. In practice, this rarely happens unless you're running extremely high loads like large hydraulic systems or industrial equipment.
A: Battery bank sizing depends on battery chemistry and manufacturer specifications, but here are general guidelines: Lead Acid (Flooded/AGM/Gel): Most manufacturers recommend charging at 10-25% of battery capacity (C-rate). For full 100-amp charging, you'd want 400-1000Ah of lead acid batteries. A 400Ah bank can safely accept 100 amps (25% C-rate), while 600Ah is more conservative (17% C-rate). Smaller banks (200-300Ah) can use the PM3-100A but won't accept full 100A during bulk charging - the converter will automatically reduce output as batteries approach full charge. Lithium LiFePO4: Lithium batteries can accept much higher charge rates, typically 0.5C to 1C. A 200Ah lithium bank can safely accept 100-200 amps, so the PM3-100A is perfect for lithium banks from 100Ah to 600Ah+. The PM3-100A's fast charging really shines with lithium - a 200Ah Battle Born bank goes from 50% to 100% in about 1 hour. Bottom line: The PM3-100A is ideal for RV house banks from 200Ah to 800Ah. Smaller banks (100-200Ah) still benefit from the PM3-100A's power output capability for running loads, even if batteries can't accept full 100A charging. Oversizing your converter is never a problem - it will only deliver the current your batteries can safely accept.
A: The PM3-100A uses a temperature-controlled proportional fan that adjusts speed based on internal temperature and load. This is normal operation and here's what to expect: Fan Runs Continuously: If you're charging heavily discharged batteries or powering high 12V loads (50+ amps), the converter generates significant heat and the fan will run continuously at varying speeds. This is normal and expected - the fan is working to keep internal components cool. In hot ambient temperatures (80°F+) or poor ventilation conditions, the fan may run more often even with moderate loads. Make sure the converter has at least 1" of free air space on each side for proper airflow. Fan Doesn't Run: During light loads (below 30-40 amps) in cool conditions, the fan may not run at all or run very briefly. This is also normal - the converter only activates the fan when needed to maintain safe operating temperature. If the converter is delivering power but the fan never runs even under heavy loads, check that nothing is blocking the airflow vents. If temperatures rise too high, the converter will shut down to protect itself (thermal overload protection). Fan Cycles On/Off: This is the most common operating mode. The fan starts when temperature reaches a threshold, cools the converter, then shuts off. This cycling is normal and expected during moderate loads. The proportional control means the fan may run at different speeds - slower for light cooling needs, faster for heavy loads.
A: Yes, PowerMax converters can be wired in parallel to combine their outputs for higher total current. Two PM3-100A units in parallel deliver 200 amps, three units deliver 300 amps, etc. This is perfect for very large battery banks (800Ah+) or applications requiring massive 12V power like mobile workshops, food trucks, or off-grid homes. Parallel wiring: Connect all positive outputs together and all negative outputs together, then connect these combined outputs to your battery bank. Use heavy gauge wire (4 AWG or larger) for the parallel connections to handle the combined current. Each converter operates independently but shares the load automatically based on its internal impedance. Important considerations: (1) Use converters of the same model for parallel operation - don't mix PM3-100A with other models or brands. (2) All converters must be set to the same voltage output, especially critical in fixed voltage mode for lithium batteries. (3) Install all converters with equal wire lengths to battery bank for balanced load sharing. (4) Mount converters with adequate ventilation since total heat output doubles/triples with multiple units. (5) Each converter requires its own AC circuit - you'll need multiple 15-amp 120VAC circuits for multiple converters. Series connection: Converters can also be wired in series for 24V or 48V systems. Two 12V converters in series output 24V, three output 36V, four output 48V, etc. Series wiring is useful for commercial, telecommunications, and alternative energy applications requiring higher system voltages.
A: The LED indicator light on the PM3-100A should illuminate when the converter is powered and outputting voltage. If the LED is not lit, work through these troubleshooting steps: 1. Check AC power: Verify 120VAC is reaching the converter. Test the outlet with another device, check that the circuit breaker isn't tripped. 2. Verify battery voltage: This is the most common cause of no LED. The LED only lights when the converter's output voltage is HIGHER than the battery voltage. If you've set the fixed voltage mode to 13.2V but your batteries are at 13.5V, the LED won't light because the converter isn't actually charging (current flows from higher to lower voltage). Solution: Increase the fixed voltage setting above battery voltage, or if in 3-stage mode, ensure the voltage is set to 14.6V (factory default). 3. Check voltage mode switch: Make sure Switch A is in the correct position ("Three Stage" for automatic charging or "Fixed Voltage" for constant output). 4. Measure output voltage: Use a voltmeter on the DC output terminals. If you read 14.6V (or your set voltage) but the LED isn't lit, the LED itself may be defective - converter is still working fine. If you read 0V or very low voltage, proceed to step 5. 5. Check for blown fuses: The PM3-100A has internal reversed-battery fuses that blow if battery connections are reversed. If you accidentally connected positive to negative (easy mistake), these fuses protect the converter but require replacement. Contact PowerMax tech support for fuse replacement under warranty. If none of these steps resolve the issue, contact PowerMax technical support - the converter may need warranty service.