Winter is hard on padlocks. We know. We live in Canada. Cold can make oil sticky. Freezing rain and a hard frost can seal moving parts. Here are some things you should be considering when deploying keyless padlocks in a winter climate.
Battery Types
Most battery types (and all rechargeable types we know of) have significantly shorter battery life as temperatures drop below freezing. A typical rechargeable battery will not only lose charge in the cold, but will not recharge well in the cold either. Batteries that can’t perform in the cold will leave you locked out in the cold.
When a battery has charge, it needs to be designed for the cold to deliver its rated current in the cold. This is why automotive batteries in cold climates advertise Cold Cranking Amps. Lower current leads to less powerful or slower internal motor operation. This may result in a lock that does not open or close as it was designed to do.
The solution is simple. Ensure a battery is designed to work in the cold for reliable winter performance operation.
Sera4’s AP3 padlock uses replaceable Lithium Thionyl Chloride batteries. These military-grade batteries are formulated to perform similarly in the coldest and hottest natural temperatures on Earth. In the event that the battery is out of power after a time (this happens to every battery), the micro-USB port is convenient and accessible and facilitates access. An added bonus is that maintenance is a lot faster on a replaceable battery than with a rechargeable padlock. We can also deliver our products will full charge and ready-to-deploy, where rechargeable batteries need to ship at 30% charge.
Electronics
Electronics used outdoors in the winter must be designed and qualified for reliable use in cold temperatures. Consider that most consumer electronics in winter climates is still consistently used above the freezing point. Electronics require additional design and quality considerations to function reliably in deep cold. Designing electronics for the cold follows well-known quality standards (such as AEC-Q100), requiring specific attention during product development. We don’t expect consumer-grade electronics to consistently work outside in the dead of winter.
Ice Buildup
You should be concerned about ice buildup on padlocks in the winter. Humidity or water can get into parts of a lock and then freeze. Once there is solid ice around a mechanism that needs to move to open or close, the best thing to do is to melt the ice. This is obviously inconvenient. We recommend focusing on simple installation tricks that will keep precipitation off the padlock in the first place. AP3 is IP66-certified, so it will be fine to be left out for years in the rain. In winter climates, we recommend installing a simple vinyl flap over top of the padlock as shown below. This simple solution has proven in our tests to be more effective than more complicated approaches.
In case you do find a padlock with significant ice deposits, try to resist the urge to hit at it with a hammer to chip away at accumulated ice. This usually only removes superficial ice and can result in surface/finish damage to the padlock body or shackle. Instead, try pressing the shackle deeper into the lock body. This will often dislodge stuck components. Another smart option is to use a lock de-icer fluid. These bottles are small, inexpensive and effective.
Don’t let winter get between you and the benefits of going keyless. With the right products and a little bit of care during installation and operation, winter won’t be an issue. Feel free to talk to us if you have any questions about padlocks in winter weather.