If you own a 2014–2017 Roadtrek Adventurous with the E-Trek system, you’ve got a premium off-grid power setup that was cutting-edge a decade ago. You’ve also got a ticking time bomb—or at least a system walking a razor’s edge between innovation and obsolescence. The Valence lithium modules that power it are no longer manufactured. Roadtrek itself went bankrupt in 2019. When your E-Trek fails—and statistically, many do—you’re on your own.
This guide walks you through what the E-Trek actually is, why it fails, how to diagnose problems, and most importantly, your realistic retrofit options.
What Is the E-Trek System?
The E-Trek was Roadtrek’s premium lithium house battery option for the 2014–2017 Adventurous class B motorhome. It’s a tightly integrated package:
Core Components:
- Valence 13.6 kWh lithium house bank — Four KS2-series LiFePO4 modules (3.4 kWh each) wired in series/parallel to create a 48V nominal bank rated for 200 A continuous discharge
- Underhood second alternator — A 150A unit separate from the engine alternator, designed to charge the lithium bank while driving
- Magnum 3000W pure sine-wave inverter — Powers 120V AC loads when off-grid or parked
- Battery Management System (BMS) — Electronic controller that regulates charge/discharge, monitors cell voltage, and protects against over-charge, over-discharge, and thermal runaway
- Dedicated wiring and contactors — Heavy-gauge DC distribution with solid-state relays to isolate the bank and handle switching
For 2014, this was genuinely innovative. It offered 3–4x the usable capacity of lead-acid, zero self-discharge, zero maintenance, and the ability to run AC loads indefinitely at a campground or while dry-camping. Premium pricing reflected premium capability.
Then the supply chain collapsed.
The Double Bankruptcy Problem
Two events destroyed the E-Trek ecosystem:
Valence Energy Bankruptcy (2015): Valence, the California-based lithium cell and module manufacturer, filed for Chapter 7 liquidation in October 2015. The KS2 modules—the heart of the E-Trek—were never produced again. Roadtrek had already begun shipping systems; the company continued using existing inventory through 2017 but had no path to long-term supply or service. No other manufacturer has ever made a drop-in replacement for the KS2. The BMS, designed specifically around Valence cell chemistry and electrical characteristics, cannot be repaired or reflashed by field technicians. If the BMS fails, the entire module (not just the board—the whole unit) must be replaced, which is now impossible.
Roadtrek / Erwin Hymer Group Bankruptcy (February 2019): Roadtrek was acquired by Germany-based Erwin Hymer Group in 2016. Hymer filed for insolvency three years later. Any remaining factory inventory, documentation, or support infrastructure was liquidated. The company that sold you the E-Trek no longer exists in a form capable of honoring a warranty or providing technical guidance.
The practical consequence: If your E-Trek battery fails, you cannot buy a replacement battery. You cannot get the BMS reflashed or repaired. You cannot call Roadtrek customer service. You own a 13.6 kWh lithium system that is functionally orphaned.
Common E-Trek Failures
Field reports and owner groups paint a consistent and troubling picture:
Battery Failures Within Months: Many owners report that one of the four Valence modules fails within 6 months of taking delivery. The symptom is usually immediate: the BMS stops charging that module, the inverter shuts down intermittently, and voltage becomes erratic. The root cause appears to be incorrect internal wiring of the KS2 modules themselves—specifically, the charge and discharge ports must be wired in a specific polarity and sequence. If a module left the Valence factory or was installed by Roadtrek with reversed ports, it will fail silently when first charged.
BMS Electronic Failures: The BMS can fail independently of the batteries. Symptoms include:
- No charging from the alternator despite good alternator output voltage
- No charging from shore power (campground pedestal)
- Intermittent power loss mid-conversation or mid-appliance run
- Complete lockout of the inverter until the system is power-cycled
These are typically board-level failures (a capacitor, relay, or firmware corruption) inside the BMS. They cannot be repaired in the field. The BMS is not user-serviceable.
Load Dump Events: When the lithium bank is fully charged and the alternator continues to push current, the BMS is supposed to open a contactor (electronic relay) to protect the system. On some E-Trek installations, this contactor either sticks closed or fails to open cleanly. The result is a rapid voltage spike—sometimes up to 70+ volts—that propagates through the 12V distribution and damages downstream electronics: the coach computer, the backup camera, the entertainment system, and most dangerously, the main vehicle ECU.
Discharged Lithium Creates Alternator Stress: Lithium batteries at 0% state-of-charge have much lower internal resistance than lead-acid. When fully depleted, a dead E-Trek can pull 300+ amps from the alternator during recovery charging—far beyond the 150A second alternator’s safe duty cycle. One owner reported the alternator harness overheating and beginning to smoke while the BMS attempted a rapid recharge. The potential for electrical fire is real.
Relay Clicking and GFCI Tripping: Many owners report a rhythmic clicking sound (~1 per second) from the BMS relay cabinet, accompanied by intermittent tripping of shore-power GFCI breakers. This suggests the BMS is rapidly opening and closing its main contactor in response to a fault condition it cannot resolve—usually over-voltage, under-voltage, or thermal shutdown cycling.
Silent Power Drain: Some E-Trek systems continue to draw 2–5 amps even when parked with all loads off. This can drain the house bank to unsafe levels in 2–3 days. The culprit is often a failed BMS relay stuck half-open, creating continuous quiescent current draw.
Diagnosing E-Trek Problems
Before you assume your E-Trek is dead, run through these diagnostics. You’ll need a quality multimeter and a basic understanding of DC voltage.
Visual Inspection:
- Open the battery compartment and look for the four Valence KS2 modules. They are gray aluminum-cased boxes about 14″ × 10″ × 4″ each.
- Check for discoloration, corrosion, or visible damage on the modules or their terminals.
- Look at the BMS cabinet (usually mounted above or next to the modules). Check for loose connections, burn marks, or relay chatter.
- Inspect all DC wiring for burned insulation or pinched connections.
BMS Status Lights: The BMS has a set of indicator LEDs on its front face. Consult your owner’s manual (or hunt down a digital copy on Roadtreking.com or Class B Forums) to read these lights:
- Green = normal operation
- Red = fault (over-voltage, under-voltage, temperature, or module failure)
- Amber = warning or low state of charge
- Off = no power to the BMS
Voltage Testing:
- With the main disconnect switch ON and all AC/DC loads off, measure the voltage across the positive and negative terminals of the main battery bus (visible near the inverter). Expected: 48V nominal (range 44–54V when healthy). If < 40V or > 58V, the BMS is likely in fault mode.
- Measure each individual Valence module’s voltage (terminals marked on the module). Expected: 12.8–13.2V per module when at rest. If any module reads < 10V or > 14V, it has failed or is imbalanced.
- With the engine running and the second alternator driving, measure voltage again. Expected: 48.5–50V with alternator input (modest rise). If no rise after 30 seconds of running, the BMS is not allowing charging.
Consult a Specialist: If any of these tests show anomalies, contact a van electrification shop or post your detailed findings to the Roadtrek Owners or Class B Forums Facebook groups. Do not attempt to disassemble the BMS or Valence modules yourself—they are high-voltage systems and carry lithium fire risk.
Your Options: Retrofit or Revert
You have three viable paths forward. None of them are free, but all are better than the nightmare of owning an orphaned E-Trek.
Option A: Battle Born LiFePO4 Retrofit (Most Popular)
Replace the four Valence modules with two or four Battle Born 12V 280 Ah LiFePO4 modules (3.6 kWh or 7.2 kWh, depending on how many you install), wired in series to achieve 48V nominal. Pair with a modern BMS built into each Battle Born unit (no separate BMS cabinet needed). Add a 150A DC-to-DC charger to isolate the alternator from the lithium bank.
Why it’s popular:
- Battle Born modules are still in production and actively supported
- The company has a proven track record with RV lithium conversions
- Modular design: you can start with two modules (3.6 kWh) and add more later
- Built-in BMS is field-serviceable (firmware updates available)
- Extensive online documentation and DIY community
Cost: Two 12V 280 Ah Battle Born modules: ~$6,000–7,000. 150A DC-to-DC charger: ~$800–1,500. Installation labor: $1,500–3,000 (DIY can save this). Total: $8,300–11,500.
Critical point: You MUST install the DC-to-DC charger. It isolates the alternator from the lithium bank by stepping down the alternator’s variable voltage to a controlled 48V charge input with current limiting (~150A). Without it, the alternator can overheat trying to charge lithium directly, and load dump events can damage your engine electronics. This is not optional.
Option B: Other Lithium Manufacturers
Lithionics: American company, high-end RV-focused modules (12V 200–400 Ah). More expensive than Battle Born ($8,000–15,000 for a 48V bank). Excellent support and warranty. Often overkill for a Roadtrek’s power needs.
RELiON: Competitive pricing, similar specs to Battle Born. Good reviews from RV owners. Similar integration effort and cost.
Both require a DC-to-DC charger, same as Battle Born. The core retrofit logic is identical; only the module brand and upfront cost differ.
Option C: Revert to AGM (Lead-Acid Upgrade)
Install three high-end AGM batteries (like Lifeline or Odyssey) in place of the Valence modules, wired in series to 48V.
Pros: Significantly cheaper (~$2,000–4,000 for four quality AGMs). Zero lithium fire risk. Widely available, replaceable anywhere. No exotic charger required.
Cons: Usable capacity drops to ~6 kWh. Requires charging from shore power or the alternator every 2–3 days of boondocking. Self-discharges if parked for a month. Heavier. No longer a “premium” off-grid system.
This is a realistic choice if you dry-camp infrequently and don’t need multi-day boondocking range.
Parts and Support Resources
Van Electrification Specialists: Van Specialties (California), Advanced RV (multiple locations), and local solar/RV electric shops can handle DC-to-DC charger installation and troubleshooting.
Online Communities: Class B Forums (classb.org) has dedicated E-Trek and lithium retrofit threads. Roadtrek Owners and Roadtrek Owners Helping Roadtrek Owners on Facebook provide real-time peer support. Lithium RV (Facebook) covers broader RV lithium retrofit builds.
Technical Resources: Sprinter-Source.com for electrical troubleshooting, Battle Born YouTube Channel for installation guides, and your Owner’s Manual (hunt down a digital copy from Roadtreking.com or the Facebook groups).
The Bottom Line
The E-Trek was bold and ahead of its time. If yours is working perfectly today, protect it: keep the modules cool, avoid deep discharges, and monitor the BMS status lights religiously. But if you’re seeing any of the red flags above—intermittent charging, relay clicking, power drain, or a dead module—the kindest thing you can do is plan a retrofit now rather than limp along waiting for a catastrophic failure mid-trip.
Option A (Battle Born retrofit) is the path 90% of experienced E-Trek owners choose. It restores your original off-grid capability, you gain a modern, repairable BMS, and you can expand capacity later. The upfront cost is real, but so is the peace of mind.
For help diagnosing your specific E-Trek symptoms or planning your retrofit, visit SprinterRVDesk.com/diagnose to chat with our Roadtrek AI expert. We also have guides for related electrical and battery troubleshooting on our issues page and blog.
Safe travels. Your E-Trek adventure isn’t over—it’s just moving into its second act.