WFCO 8955 Replacement Guide: Best RV Converter Upgrade

Upgrading from the WFCO WF-8955 to a PowerMax Converters converter is one of the easiest ways to improve RV charging performance—especially for lithium battery systems, larger battery banks, and modern RV electronics.

Many RV owners replace the WFCO 8955 due to inconsistent charging behavior, limited support for lithium batteries, and a lack of voltage control. A properly matched PowerMax converter provides faster charging, adjustable output voltage, and more reliable battery performance.

Why Replace the WFCO 8955?

Common issues RV owners experience with WFCO converter chargers:

• Converter stays stuck in 13.6V “Normal Mode.”
• Charger will not reliably enter 14.4V Boost Mode
• Slow charging for lithium and AGM batteries
• Incomplete battery charging cycles
• Limited lithium battery compatibility
• No manual voltage adjustment
• Reduced charging efficiency for larger battery banks

This is especially common when upgrading from lead-acid batteries to LiFePO4 lithium batteries.

Recommended PowerMax WFCO 8955 Replacement Options

Best Direct Replacement

PowerMax PM3-55 Converter Charger

• Standard 55A replacement option
• Excellent upgrade from the WFCO WF-8955
• Smart multi-stage charging
• Reliable cooling and thermal protection
• Great for standard AGM, flooded, and lithium setups

PowerMax PM3-55-SME Adjustable Converter Charger

• Adjustable voltage output
• Ideal for lithium battery conversions
• Manual precision charging control
• LCD voltage display
• Adjustable output range from 13.0V to 16.5V

Upgrade Options (Higher Performance)

PowerMax PM3-75 Converter Charger

Recommended for:

• Larger lithium battery banks
• Faster recharge times
• Heavy inverter loads
• Off-grid RV systems

PowerMax PM3-100 Converter Charger

Best for:

• Large lithium battery systems
• High-demand RV electrical setups
• Extended boondocking applications
• Multiple battery configurations

Key Benefits of Upgrading to PowerMax

Adjustable Voltage Output

Unlike WFCO auto-mode charging, PowerMax SME models allow precise manual voltage adjustment.

Typical settings:

• Lithium: 14.2V–14.6V
• AGM: ~14.4V
• Float/Storage: 13.2V–13.6V

Faster Charging Performance

Many RV owners report significantly faster charging compared to the WFCO 8955, especially when charging lithium batteries or deeply discharged battery banks.

Lithium-Ready Out of the Box

PowerMax converters are designed to support modern LiFePO4 battery systems without relying on unpredictable “auto detect” charging logic.

Stable, Clean DC Output

PowerMax converters provide:

• Clean regulated power
• Stable voltage for RV electronics
• Low ripple output
• Reliable performance for sensitive equipment

Improved Cooling & Reliability

• Temperature-controlled fan operation
• Thermal protection
• Proven long-term reliability
• Consistent charging performance under load

WFCO 8955 to PowerMax Replacement Instructions

1. Disconnect Power

• Turn off shore power
• Disconnect the RV battery
• Verify no AC or DC power is present

2. Remove WFCO 8955 Converter Section

Locate the lower converter module inside the WFCO power center.

Remove:

• Mounting screws
• AC input wiring:
• Black (hot)
• White (neutral)
• Ground
• DC output wiring:
• Positive
• Negative

3. Install the PowerMax Converter

Mount the new PowerMax converter in the same compartment or nearby installation location.

Reconnect:

• AC input wiring to matching terminals
• DC output wiring using correct polarity

In most installations, wiring modifications are minimal.

4. Set Output Voltage (SME Models Only)

For adjustable SME models:

Recommended settings:

• Lithium batteries: 14.2V–14.6V
• AGM batteries: ~14.4V
• Float/storage: 13.2V–13.6V

The adjustable feature allows true precision charging rather than relying on automatic mode switching.

5. Test the System

• Restore shore power
• Reconnect batteries
• Confirm converter voltage output
• Verify proper battery charging operation

Is the Upgrade Plug-and-Play?

In Most Cases: YES

PowerMax PM3 replacement converters are commonly used as direct replacements for the WFCO 8955 because they offer:

• Similar footprint sizing
• Compatible wiring configurations
• Simple installation process
• Minimal modification requirements

Pro Tip for Lithium Upgrades

If you are upgrading from a WFCO converter to lithium batteries, the best option is typically the PM3-SME adjustable series.

Why?

Because it eliminates one of the most common WFCO complaints:

The converter never reliably enters boost charging mode.

With PowerMax SME models, you control the charging voltage directly for faster, more consistent lithium charging performance.