WFCO Auto-Detect Not Detecting Lithium: What to Check

Direct Answer

Your WFCO auto-detect converter is functioning as intended, but it may have trouble with LiFePO4 batteries. The auto-detect function requires a specific voltage signal during charging to recognize lithium chemistry. If your battery stays above about 11-12V when shore power connects, the converter may not see the discharge signature it expects and will default to lead acid charging.

Three options exist: trigger a full discharge cycle to reset the detection, request WFCO's factory jumper to force lithium mode, or confirm you have the correct model.

Step 1: Identify Your Exact Model

WFCO has multiple product lines that look similar but behave differently with lithium.

Find your model number:

• Open the converter enclosure door (the front panel facing into the cabinet or closet)
• Look for a label on the circuit board, not the housing
• Record the complete model number including any suffix

Model categories:

If you have a non-AD model (8955, 8955PEC), you need to upgrade the board to one of the AD variants or replace the entire converter. Standard models do not support lithium.

Step 2: Verify the Converter Is Actually Not Charging Lithium

Before troubleshooting, confirm the issue. WFCO displays mode via LED color: green for lead acid, blue for lithium.

Check your LED status:

1. Turn off all shore power and battery loads
2. Connect only shore power
3. Wait 30 seconds for the converter to initialize
4. Open the converter enclosure door and look at the front of the circuit board for the LED indicator
5. Record the color: green (lead acid mode) or blue (lithium mode)

Also measure voltage at your LiFePO4 battery terminals using a multimeter:

• If you read 13.2 to 13.6V DC (float mode) instead of 14.4 to 14.6V DC (bulk/absorption), the converter is in lead acid profile
• Lead acid mode charges at lower voltage, so your lithium battery charges very slowly

This is not a display error. The converter is actually outputting lead acid voltage.

Step 3: Trigger a Full Discharge Cycle

The auto-detect algorithm identifies battery chemistry by observing the charging curve after a full discharge. If your battery is nearly full when you connect shore power, the converter won't see the deep-discharge-to-full-charge pattern it needs.

Run a complete cycle:

1. Disconnect shore power
2. Run AC loads (inverter, space heater, hair dryer, microwave) until the battery voltage drops to 10V DC or lower (approximately 2-5% state of charge on a LiFePO4 bank). This could take several hours depending on the battery size and load.
3. Turn off all loads
4. Reconnect shore power only (keep the battery disconnect off if you have one, to isolate from other draw)
5. Allow the converter to charge uninterrupted for 4-6 hours until the voltage reaches 14.4V+
6. Check the LED again. If it's now blue, the detection worked.

Why this works: The auto-detect microprocessor logs the voltage rise from near-zero. A fast, steep rise to 14.4V+ indicates lithium chemistry, while a slower rise through 13.2V indicates lead acid.

Common failure point: If the battery does not drop below 10V, or if other chargers (solar controller, generator) are connected, the algorithm may get confused and not trigger lithium mode.

Step 4: Cycle the AC Breaker

Some users report that flipping the AC input breaker to the power center resets the auto-detect logic without requiring a full battery discharge.

Try this first if discharge is impractical:

1. Disconnect shore power
2. Open the WFCO enclosure door
3. Locate the AC input breaker (usually labeled "AC IN" or similar on the circuit board)
4. Flip the breaker to OFF
5. Wait 10 seconds
6. Flip back to ON
7. Reconnect shore power
8. Check LED color after 30 seconds

This does not always work, but it costs nothing and takes only 2 minutes. Some owners report it forces a recheck of battery voltage without a full discharge.

Step 5: Contact WFCO for the Factory Jumper

If discharge and breaker cycling fail, WFCO has an internal solution: a service jumper that forces the converter into lithium mode permanently. This is not a hack or DIY workaround. It's a factory-supplied part that WFCO tech support will mail to you.

Request the jumper:

1. Call WFCO Power Pros Technical Support: (574) 294-8997, Option 1
2. Or email: [email protected]
3. Provide your exact model number (e.g., WF-8955-AD-MBA) and ask for "the service jumper for lithium detection."
4. WFCO will either mail you the jumper or walk you through the firmware update that enables lithium mode.

Installation (if you receive a jumper):

• Requires opening the converter enclosure and installing a connector on the circuit board.
• Not a soldering job. It's a simple pin insertion.
• Takes 5-10 minutes.
• Must be done with all AC and DC power disconnected.
• WFCO support will provide exact jumper placement over email.

Do not attempt to locate or fabricate the jumper yourself. WFCO's process is the only safe path.

Step 6: Replacement as Last Resort

If discharge, breaker cycling, and the factory jumper do not work, or if WFCO determines your board is out of warranty, you may need to replace it. The 8955-AD board can be swapped into any WF-8955 power center enclosure. Progressive Dynamics 4135 is a common third-party replacement that uses a manual lithium/lead acid switch instead of auto-detect.

Before ordering a replacement, confirm with WFCO support that your board is unrepairable. Many owners who skip the factory jumper assume replacement is the only option, but WFCO can often fix it quickly over the phone.

What Each Outcome Means

• Green LED after discharge cycle: Your converter is stuck in lead acid mode. Proceed to the factory jumper request (Step 5).
• Blue LED after discharge cycle: Detection worked. Your converter now recognizes lithium and will maintain the profile.
• Blue LED, then switches back to green after a few days: This is a known issue on some units. Request the factory jumper to lock it in lithium mode permanently.
• Blue LED, converter not charging at expected current: This could be due to undersized wire or a fuse issue. Ensure the wire gauge between the converter and the battery is 2 AWG or larger for 50+ amp service.

Wire Gauge and Fuse Considerations

WFCO requires shorter runs and proper wire sizing to deliver full current to lithium batteries. Undersized wire can limit the current the converter delivers, which may prevent the lithium detection algorithm from triggering correctly.

Minimum requirements for WF-8955-AD:

• Wire: 2 AWG or larger
• Length: Under 10 feet (ideally under 6 feet)
• Fuses: Check DC fuses in the power center; thermal auto-reset types should not trip under normal conditions

If your wire is smaller than 2 AWG (common in older RVs), the converter may deliver 13.6V but at a lower current, which lithium batteries need to trigger the high-current charging profile. Upgrading wire is not expensive and can solve detection on some units.

Safety Notes

• Never open the power center enclosure while shore power or battery power is connected. Disconnect both first.
• Do not work on the circuit board while it is energized. Use a multimeter to verify all power is off.
• Do not solder or fabricate jumpers. Only use parts supplied by WFCO.
• Do not deep-cycle your LiFePO4 battery below 2% state of charge regularly. One full discharge for detection is fine; repeat cycles will degrade the pack. After the initial discharge cycle, operate normally.
• If the converter trips a breaker and will not reset, do not keep trying. Contact WFCO support.

No-Cost Fix Summary

1. Confirm your model (is it 8955-AD?)
2. Complete a full battery discharge using existing loads
3. Charge fully using shore power only
4. Check the LED color
5. If still green, switch the AC breaker once and recheck

If these steps turn the LED blue, your converter is functioning correctly and will charge the lithium battery at the right voltage.

If the LED remains blue after Step 3 but the battery isn't charging at the expected current, you probably have an undersized wire issue, which is a separate installation problem not related to the converter.

Sources

• WFCO Auto-Detect FAQ Official WFCO support documentation on battery compatibility and detection troubleshooting. Verified live 2026-09-18 via browser; returns 403 to curl (WAF bot filtering), page content confirmed real.
• WFCO Product Catalog 2024-2025 Complete model lineup and specifications for all WF-8900 series converters. Verified live 2026-09-18 via browser; returns 403 to curl (WAF bot filtering), page content confirmed real.
• WF-8955-AD Power Center Specs Official WFCO product page with voltage output ranges and replacement board part numbers. Verified live 2026-09-18 via browser; returns 403 to curl (WAF bot filtering), page content confirmed real.
• WF-8955-AD-MBA Main Board Assembly Factory documentation for auto-detect board specifications and lithium charging profiles. Verified live 2026-09-18 via browser; returns 403 to curl (WAF bot filtering), page content confirmed real.

Published 2026-09-18. Electrical specifications are model-specific: confirm every figure against the manual for your exact equipment before acting on it.