Replace the Key Fob Battery

Last updated: June 10, 2026

If the key fob on your NIO ET7 (2022–2024) has gone weak or the locking has become intermittent, the coin cell inside is almost certainly flat. Note that this fob uses a larger-than-usual CR2477 cell — check before you buy.

Battery First — What You Need

• A CR2477 coin cell (not the common CR2032 — the NIO fob takes the larger CR2477).
• A thin plastic prying tool.

Replacing the Cell

1. Pinch the sides of the key firmly.
2. Use a thin plastic tool to separate the cases.
3. Remove the old cell.
4. Fit a new CR2477 with the positive side facing DOWN (as marked).
5. Refit the cases and check the remote locks and unlocks the car.

Lost Key or Adding a Spare

A cell swap keeps the existing coding. A lost or broken key can only be ordered and programmed by NIO — there’s no owner sequence.

If a Fresh Cell Doesn’t Help

• Make sure it’s a CR2477 and fitted positive-side down.
• Use the phone key (NIO app) in the meantime.
• Still intermittent? A receiver fault can store a code — look it up on autodtcs.com.

Frequently Asked Questions

What battery does the NIO ET7 key use?

A CR2477 coin cell — larger than the usual CR2032 — fitted positive-side down.

Do I need to reprogram the key after the swap?

No — the coding is retained for a battery change.

Why won’t a CR2032 work?

It’s too thin to contact properly — the fob is designed for the thicker CR2477.

Can I still get in with a dead fob?

Use the NIO phone key as a backup.

If the fob stopped working after a 12 V issue, see our NIO ET7 12V battery guide.