Everything You Need to Know. VanMoof Main Battery
VanMoof SX3 Main Battery
Why Did My VanMoof Main Battery Fail?
1. Deep Discharge Due to Long-Term Storage
The bike was left uncharged for an extended period, causing the main battery to enter a deep-discharge state.
Solution: Perform a controlled battery jump-start.
2. Harness Loom Damage
Damaged cables inside the frame can trigger a safety response in the Smart Cartridge, which blocks the main battery to prevent overheating or fire.
Solution: Replace the harness loom.
3. Smart Cartridge Power Distribution Faults
Low-quality or failing components in the Smart Cartridge can cause power spikes to reach the main battery, blowing the main fuse.
Solution: Replace all weak or faulty components involved in power distribution.
4. Smart Cartridge Low-Voltage Logic Failure
Some components operate outside their specifications and draw excessive power from the Smart Battery. This drains the Smart Battery, preventing the bike’s “brain” from booting correctly. As a result, false signals may be sent to the main battery fuse, blocking the main battery.
Solution: Identify and replace out-of-spec components. When inactive, the Smart Cartridge should draw virtually no power.
5. Main Battery BMS Failure
The Battery Management System (BMS) does not properly disconnect the battery when voltage becomes too low.
Solution: Repair or replace the BMS.
6. Cell Imbalance in the Main Battery
The battery cells are no longer balanced, leading to unstable performance or shutdowns.
Solution: Rebalance the cells using a battery equalizer.
7. Physically Damaged Battery Cells
One or more cells in the main battery pack are damaged or degraded beyond recovery.
Solution: Replace all 40 battery cells.
How to Check if the Smart Cartridge Battery Is Working.
- Plug in the charger and leave it connected for five minutes. It is expected if the charger's LED is flashing green and red.
- Reboot the bike by holding down the power button (more details here).
- Within 30–60 seconds, the charging progress bar symbol should appear on the matrix display (an example can be found here).
- Leave the bike charging for another 10-30 minutes.
- Unplug the charger and reboot the bike.
If the bike shows signs of life (e.g., sounds or activity on the matrix display), the battery is working.
If the matrix display remains off or there are no signs of life, the Smart Cartridge battery likely needs replacement.
⚠️ Important Safety Notice
- Only attempt this if you are experienced with high-voltage lithium battery packs.
- Always wear protective gear (gloves, goggles).
- Work in a fire-safe, ventilated environment.
- Do not short any terminals or expose cells to heat or moisture.
- Do not use or keep any conductive tools (e.g., metal tweezers, screwdrivers) near the battery during the procedure.
- Keep your desk clean and free of unnecessary tools or objects.
- Ensure there are no liquids on or near the work area.
How to remove SX3 Main Battery
PLEASE APPLY EXTRA CARE WHEN HANDLING THE CABLE UNDER THE BATTERY COVER
This cable is delicate and prone to damage, with potential repair costs of up to £500.
Please handle it with care to avoid any pressure or jamming. Note that the cap covering the battery bed has holes specifically designed for this cable, so be sure to align it properly during installation.
To remove the battery, you’ll need a T25 Security Torx screwdriver:
Make sure it’s a T25 Security Torx, not just a regular T25 Torx.
Please use the following video as the main reference (English).
How to open SX3 Main Battery
Required Tools & Materials
- Insulated screwdriver set
- T25 Torx bit (to remove the main battery)
- Multimeter
- Heat-resistant gloves
- Safety glasses
- (optional) Plastic spudger (non-metallic prying tool)
How to remove SX3 Main Battery's BMS
All major steps can be found here