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Troubleshooting

NIU KQi scooters: error 41 after storage (battery over-discharge) and error 42

Error 41 shows when a KQi was left uncharged for weeks or months, and NIU's fix is to charge it straight away. Error 42 is a battery communication fault that goes to NIU after-sales if it stays.

Last edited Nov 9, 2026 by Pedalwise team Edit History Add a subpage

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You take the scooter out after a few weeks or months and the dashboard shows a red 41. This is a battery over-discharge warning, caused by leaving the scooter unused without charging. The fix is to charge right away (NIU error 41). A red 42 is different: it is a battery communication and verification fault (NIU error 42). Look any code up in the troubleshooting chapter of your own manual, since codes can differ by model. Manuals for the KQi 100, KQi 300 and KQi Air are in the NIU download center.

The battery is sealed inside the deck and is not removable (NIU FAQ). Never open the deck to get at it and never try to reset or bypass its protection. Battery faults go to NIU after-sales or a qualified shop. See battery care.

Most likely cause

A lithium battery slowly loses charge while it sits. Left long enough without charging, it drops low enough that the scooter warns you with 41 (NIU error 41, FAQ).

Other causes to rule out

  • A charger fault, if the scooter still won't take a charge. See battery won't charge.
  • Error 42 instead of 41. NIU links it to unplugging the scooter from power. Its article's step is to limit the speed to 6 km/h, and if the code persists, to submit its service form (NIU error 42).

How to confirm

  1. Read the code carefully: 41 or 42.
  2. Plug in the charger and check its light. A charger plugged into the wall on its own should show green (battery doesn't charge).
  3. Charge somewhere between 0 and 45°C (FAQ).
  4. After a full charge, power on and check whether the code is gone. The NIU app shows charge cycles if you want to check battery history (NIU FAQ).

Fix options

Charge it now (easy)

NIU's fix for 41. If the scooter charges and the code clears, you are done. Keep it topped up while stored.

Contact NIU after-sales (pro)

If 41 stays after charging, or 42 keeps showing, submit NIU's online form so after-sales can follow up (NIU error 41). The battery has a 2 year warranty (FAQ), so check that before paying for anything. North American owners can start a claim on NIU's after-sales platform.

Keep it from happening again

Charge the scooter before it sits, and top it up while stored. See store your battery for winter.

Parts

  • None for the rider. A battery replacement is an after-sales job.

When to get a pro

A battery that won't charge after 41, a code 42 that won't clear, or any swelling, heat or smell from the deck. See battery won't charge, battery drains fast and NIU scooter troubleshooting.

Sources

Stuck after these checks? Find a shop near you.

Need a pro?

If these steps didn't fix it, find a shop near you in our partner network. For battery or wiring trouble, look for shops marked Battery and electrical.

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