Where there is disruption in power supply, electronic door lock reliability depends on the design of their backup power supply system. As of 2023, according to UL Solutions’ test report on top-selling brands, 87% of smart locks support a dual power supply redundancy solution: 4 AA alkaline batteries (main power supply with median battery life of 12 months) and an emergency power supply through a 9V emergency lithium battery (which will support basic features for 72 hours). For example, Schlage Encode Plus can switch power in a response time as little as 0.3 seconds. It also stores 30 electronic unlocking functions (each of the power consumption being 0.15Wh) after power loss, while Yale Assure Lock 2 stores electric power in a supercapacitor. It still delivers three successful unlocks after a complete power loss (NIST 2022 test Report of the National Institute of Standards and Technology, USA).
Another important design is the mechanical emergency plan. Research reveals that 72% of electronic door locks available in the North American market contain physical keyholes (complying with the ANSI/BHMA Grade 1 standard), yet 38% of the keyholes jam as they rust when they are not used for a long time (Consumer Reports 2023 data). The Samsung SHP-DP728 features a hidden key compartment design. The maximum insertion and withdrawal force is maintained at 2.5-4.2N with a temperature and humidity condition between -20℃ and 50℃, and the failure rate is reduced by 64% from the general exposed type. Aqara A100 Pro has upgraded the mechanical opening success rate to 99.98% on the Japanese market by double controlling of solenoid valves (results of the power-off simulation experiment by Tokyo Electric Power Company).
The performance under adverse weather conditions is a proof of the robustness of the product. Under the 2022 Florida hurricane season, IP68 waterpoof-rated electronic door locks (like Ultraloq U-Bolt Pro) had a working normal rate of 97% when immersed in water during rain (1-meter depth of water for 1 hour). The failure rate was 41% for the regular model (IP54 standard). 2023 tests by the Norwegian Polar Institute showed that Kaadas K9 battery with lithium thionite chloride showed its capacity to be reduced by just 12% in the temperature condition of -40℃, and is therefore more suited to handling very low temperatures compared to alkaline batteries (reduction in capacity by 78%). Additionally, Google Nest x Yale has an AI-based prediction model that warns on the potential for battery exhaustion 24 hours ahead (with 93% accuracy) and has a user response time to swap out the battery that is 2.8 times quicker than the standard low battery notice.
New power technologies are shattering the power outage bottleneck. The Energizer Kinetic Lock introduced at the CES exhibition of 2024 achieves an unstoppable power outage by the kinetic energy harvesting door handle system (having a yield of 0.5mWh per activation). The laboratory simulation energy storage efficiency of 30 unlocks per day is 105%. Solar Lock Pro is yet another revolutionary solution. Its solar cells are capable of delivering a power of 1.2W at 500 Lux of light, completely substituting for battery power supply (benchmark battery life of over 5 years). The cost of a first product of this type is, however, up to 380 US dollars, or a 62% margin over the regular model (ABI Research cost analysis model).
The maintenance strategy has an immediate effect on the availability of power outages. The German TUV certification statistics indicate that the frequency of instant power failure for electronic door locks (e.g., Philips DDL702E), which are equipped with system self-diagnosis performed once a month, is merely 0.7 times a decade, and the frequency of products that are not subject to regular maintenance is even as high as 4.3 times a decade. End users can achieve maximum energy efficiency through firmware updates – Since the August Wi-Fi 4th Gen firmware was updated to V2.13, standby power draw dropped from 0.8W to 0.3W, and emergency mode battery life increased by 47%. On the supply chain side, industrial-grade MCU chip-based solutions (e.g., Samsung SHP-P71) are stable within a ±20% range of voltage swing and have 300% greater adaptability compared to consumer-grade chip solutions (tolerance ±10%).
From dual power supply to disaster level, electronic door locks have now achieved 98.6% availability in power-off modes (NIST 2024 benchmark test). In the process of selection, the users need to balance the Type of battery (lithium thionyl chloride batteries are 40% higher in price than alkaline batteries but have a lifespan three times longer), emergency interface compatibility (the support rate of Type-C power banks can reach 79%), and extreme environment qualifications (MIL-STD-810G military standard, etc.). In the immediate future, sixth-generation devices that use wireless power delivery (e.g., the Qi standard) and biofuel cells could completely eliminate the threat of power blackouts.
