Battery empty: how to open your lock

When the battery of your TMD Chain Lock is completely empty, the lock no longer responds to the button and does not connect to the app. In this article you can read how to still open your lock, even when you are on the go.

How to open the lock

1. Attach the charging cable to the bottom of the lock. It connects magnetically.
2. Plug the USB-C end into a power source. This can be a wall adapter, but also a power bank or your phone (if it has a USB-C port).
3. Let the lock charge for a few minutes. While charging, the button shows a white rotating light.
4. Open the app and walk to the lock. As soon as it connects, you can open the lock as usual.

A few minutes of charging is enough to open the lock. A full charge from 0 to 100 percent takes about 2 hours.

On the go without a charging cable

If you don't have the charging cable with you, you can't charge the lock. In that case, please contact support and we'll look for a solution together. You can also order a spare charging cable from our webshop.

How to prevent an empty battery

• On average a full battery lasts 9 months.
• When the battery is almost empty (below 20%), the lock button flashes orange three times and you hear three beeps. You will also receive a notification in the app. Charge the lock as soon as possible after that.
• Leaving your bike for a longer time, for example at the airport or during a holiday? Fully charge the lock beforehand and take the charging cable with you.
• Keep the charging cable in a fixed place, for example in your bike bag.

Updated on: 11/02/2026