Confirm your display model before using a code table. The same number can mean different things on different displays or firmware. Identify your bike and display first.

New Defiant ST: this model does not use the L300. Do not use the L300 table for it. Its exact display model is not confirmed here, and the L04NH table must not be assumed to apply. Send support a display photo and the exact code for the correct reference.

L300 — EN-V1.3 manual

Open the L300 manual.

L04NH / L04N-H — protocol-specific table

The supplied manual labels this table “Lithium Battery No.2 protocol.” Use it only when support confirms that it matches your display/firmware.

The supplied translation is unclear for codes 2 and 5. Send support a display photo for confirmation rather than using another display's definitions.

Open the L04NH manual.

What to do with an error

Stop riding and photograph the full screen and exact code. Turn the bike off before inspecting visible cables. Do not open the controller, bypass sensors, or change factory parameters to clear the error. For low-voltage indications, follow the charging guide only if the battery and charger are undamaged. If the code persists or is not listed, contact support with your model and display photos.

Check the screen first

Stop in a safe place. Note the battery indication, assist level, and any error code. If the screen is blank, follow the battery charging guide and contact support if it remains unresponsive.

1. Identify the display. Use the bike and display guide to find the correct manual. For an L300, use + / − to select an assist level as described on page 6 of its manual. For another display, follow its own instructions.
2. Check the brake levers. Make sure they return normally when released. If a lever sticks or the display reports a brake error, stop riding and contact support. Do not disconnect or bypass brake-cutoff wiring.
3. Check visible cables with power off. Look for a loose, pinched, or damaged cable. On a Defiant, check the visible motor-wire connection near the rear fork. Do not pull wires, force a connector, or reconnect anything while powered on; send support a photo if unsure.
4. Record any error. Use the display-specific code reference. A code identifies a fault condition, not necessarily a part that needs replacement.

Do not change voltage, wheel size, drive mode, or factory settings to troubleshoot a motor problem. If the problem remains, avoid further riding and prepare a service request. Do not operate the throttle or motor while inspecting cables or brakes.

References: L300 manual, L04NH manual, and Defiant motor-connection note.

Start with the battery and charger condition

If the battery is swollen, leaking, damaged, unusually hot, or has an unusual smell, stop using and charging it. Do not open the pack or try to repair its cells. Contact Jupiter Bike Support. If it is smoking or on fire, leave the area and call emergency services.

Checks you can make safely

1. Turn the bike off. Use the charger supplied with this bike, or a replacement Jupiter Bike has confirmed is compatible. A matching plug alone does not establish compatibility.
2. Check the outside of the charger, cable, plug, and battery charging socket for damage or moisture. Do not use damaged equipment or insert tools into the socket.
3. Follow your bike manual's charging sequence, temperature limits, and charge time. Avoid hot, cold, or damp charging locations. Let a hot battery cool before charging.
4. Charge only while you are present and awake. Unplug when charging is complete; do not extend the charge time to force an unresponsive battery to charge.

If charging still does not start

Do not put the battery in a freezer, heat it, bypass its protection, or use a different charger to try to revive it. Send support the bike model, battery and charger label photos, charger-light behavior, and when the issue began.

Prepare your support request · Battery care and storage

Charging guidance: CPSC charger safety. Battery condition and temperature guidance: battery safety guidance.