Wholesale BMW i3 Battery High-Voltage Fuse Box – The $89 OEM-Spec Safety Component That Prevents Costly “No Power” Comebacks (Now in Stock for Bulk Buyers)
“A technician in Rotterdam spent two days troubleshooting a 2019 BMW i3 that showed ‘Check High-Voltage System’ after a new battery install. Voltage tests looked fine—until he checked the high-voltage fuse box. The original unit had micro-cracks from thermal cycling, causing intermittent resistance spikes. He replaced it with a new OEM-spec fuse box from CNS BATTERY, cleared the codes, and the car ran flawlessly. Total parts cost: $89. His note to the team: ‘We used to ignore this part. Now we replace it on every i3 battery job—it’s cheaper than a diagnostic comeback.’”
If you install or service BMW i3 battery packs, you’ve likely faced mysterious high-voltage faults that vanish after replacing one overlooked component: the battery high-voltage fuse box.
- It’s not just a fuse—it’s a critical safety interface between the pack and the vehicle’s HV network
- Original units degrade silently: plastic housings crack, busbars oxidize, contact resistance rises
- Aftermarket knockoffs lack arc-quenching design, risking fire during short circuits
- Most shops only replace it after a failure—turning a $90 part into a $400 diagnostic bill
But what if you could source a brand-new, OEM-engineered high-voltage fuse box—with exact current ratings, thermal stability, and BMW-compliant materials—at wholesale pricing, ready to bundle with every i3 battery replacement?
Now, professional EV workshops across Europe and North America are doing exactly that—and CNS BATTERY, as a direct manufacturer deeply embedded in the BMW i3 ecosystem, offers a Wholesale BMW i3 Battery High-Voltage Fuse Box built to factory specifications, rigorously tested, and available in bulk to ensure your installs are both safe and service-proof.
Clarification: The high-voltage fuse box (sometimes called the HV junction box or service disconnect) is mounted directly on the i3 battery pack’s positive terminal. It houses the main 400A pyro fuse, manual service disconnect (MSD) handle, and HV interlock loop (HVIL) contacts. Even minor internal resistance here can trigger BMS errors like “High-Voltage System Fault” or “Power Reduced.” CNS’s version replicates BMW’s original design—including ceramic fuse housing, gold-plated HVIL pins, and flame-retardant PBT casing—so it integrates seamlessly and performs reliably under load. For shops tired of unexplained post-install faults, this isn’t an accessory—it’s a foundational reliability component. In 2026, with i3 battery replacements becoming routine, skipping this part is like installing new tires without balancing them.
This guide reveals how proactive fuse box replacement is reducing comebacks—and how bulk access ensures you never delay a job waiting for this critical piece.
Why “Reusing the Old Fuse Box” Is a Hidden Risk
| Failure Mode | Reused OEM Fuse Box | New CNS High-Voltage Fuse Box |
|---|---|---|
| Housing Integrity | Brittle from heat cycles; prone to cracking | New UL94 V-0 flame-retardant PBT |
| Contact Resistance | Oxidized terminals → voltage drop | Gold-plated HVIL + tin-coated busbars |
| Fuse Performance | Pyro fuse may be fatigued from past surges | Fresh 400A Class-T fuse with certified interrupt rating |
| HVIL Signal | Intermittent open circuit → BMS shutdown | Stable <0.1Ω continuity guaranteed |
| Warranty Exposure | Fault traced to reused part = your liability | Full 2-year coverage when installed with CNS pack |
⚠️ Real-world insight: Over 31% of “no-start after battery install” cases in i3s are linked to HVIL or fuse box issues—not the pack itself.
🔌 CNS BMW i3 High-Voltage Fuse Box: Precision Safety, Priced for Prevention
✅ Key Specifications
- Part compatibility: All BMW i3 models (2014–2021), including REx
- Main fuse: 400A DC, 500V, ceramic body, arc-quenching design
- HVIL rating: 12V / 2A, gold-plated contacts
- Housing material: PBT GF30, UL94 V-0 rated, -40°C to +130°C stable
- Connector type: OEM-style lever-lock with secondary retention
- Weight: 320g (matches original)
📦 Wholesale Program (2026)
- MOQ: 5 units (ideal for shop inventory)
- Pricing Tiers:
- 5–19 units: $89 USD each
- 20–49 units: $84 USD each
- 50+ units: $79 USD each
- Packaging: Anti-static bag + foam insert in recyclable box
- Shipping: Global via standard courier (non-hazardous)
- Support: Includes torque specs, installation diagram, and HV safety checklist
Every unit is 100% new production—never refurbished, never pulled from cores.
✅ Strategic Advantages for Professional Shops
- Eliminate diagnostic guesswork: Rule out fuse box issues upfront
- Bundle as “HV Safety Refresh”: Add $150–$200 service value per job
- Prevent warranty voids: Many pack warranties require new HV interfaces
- Enhance shop reputation: “They replaced everything that matters.”
- Reduce comebacks: One less variable in complex HV systems
“Since we started replacing the fuse box on every i3 battery job, our post-install error rate dropped by 76%. It pays for itself in saved labor.”
— Baltic EV Specialists
Frequently Asked Questions: Wholesale BMW i3 Battery High-Voltage Fuse Box
Q: Does this include the manual service disconnect (MSD) handle?
A: Yes—the orange pull-handle is integrated and matches OEM ergonomics.
Q: Can I use this with non-CNS battery packs?
A: Absolutely. It’s a direct replacement for BMW part numbers like 82117302307 and fits all i3 HV architectures.
Q: Is special tooling required for installation?
A: No—standard HV safety gloves and a 10mm insulated socket are sufficient.
Q: What’s the interrupt rating of the fuse?
A: 400A @ 500V DC, with arc-quenching chamber compliant with IEC 60269-6.
Q: Do you test each unit before shipping?
A: Yes—every fuse box undergoes continuity check, insulation resistance test (>100 MΩ), and visual inspection.
In High-Voltage Systems, the Smallest Link Determines the Whole Chain’s Strength
And with CNS, you’re not gambling on a decade-old plastic box—you’re installing confidence.
Stop Letting a $90 Component Sabotage Your $6,000 Battery Install—Stock Up on Wholesale BMW i3 Battery High-Voltage Fuse Boxes and Make Every Replacement Job Complete, Safe, and Service-Proof from Day One.
Because true professionalism means replacing what’s worn—not just what’s broken.
Order Your Bulk Inventory Today—Get Volume Pricing, OEM-Spec Quality, and Peace of Mind for Every BMW i3 High-Voltage System You Touch:
👉 https://cnsbattery.com/ev-battery-home/ev-battery-contact/