Replace/upgrade the current battery pack with accumulators that can be charged by USB (USB-3).
The new battery pack would have the same dimensions. But it would have as well a power input (even better several: USB micro, USB-3, maybe lightening) to recharge it. Users could use another power bank to charge it “overnight” by just hanging the power bank to the door handle. No need to take it out, to remove the battery pack.
- ease of use: no need to remove the battery pack
- environmental friendly: no need to use batteries
- reducing the risk of low battery
- an embedded power bank might be more powerful than rechargeable or single use batteries.
- included into new future SmartLocks
- to be bought as additional device, for people who would prefer to charge the “new power bank” at a plug.