Complete Guide to Batteries for Smart Home Devices

As smart home devices become more prevalent ensuring they remain powered is important to keeping your automated smart home running smoothly. While some smart devices are mains powered, many rely on batteries, making it important to choose the right type for longevity, reliability, and safety. Here’s a guide to the batteries most commonly used in smart home tech.

Common Battery Types in Smart Home Devices

AA and AAA Alkaline Batteries

Used in: motion sensors, contact sensors, and thermostats.
Pros: Inexpensive, widely available.
Cons: Lower capacity and shorter lifespan than lithium alternatives.
Lifespan: 6 months to 2 years depending on the device and usage.

CR123A Lithium Batteries

Used in: Motion detectors and smoke detectors.
Pros: High energy density, longer shelf life, reliable in extreme temperatures.
Cons: More expensive
Lifespan: Up to 3 years.

Button Batteries (e.g. CR2032, CR2450)

Used in: Door/window sensors, smart buttons and temperature/humidity sensors
Pros: Compact, cost-effective, long shelf life.
Cons: Limited capacity, not ideal for frequent or high-drain tasks.
CR2032 vs. CR2450: CR2450 is thicker and has a higher capacity, better for slightly more power-hungry devices.
Lifespan: 1 to 2+ years depending on use and quality.

Rechargeable (non removeable) Lithium-ion Batteries (Li-ion)

Used in: Video doorbells, smart locks, indoor/outdoor cameras.
Pros: Rechargeable, eco-friendly over time, high capacity.
Cons: Degrades over time, requires charging setup.
Lifespan: 1–3 years or 300–500 charging cycles.

Proprietary Batteries

Used in: Brand-specific smart devices like Ring, Arlo, or Google Nest products.
Pros: Tailored for the device, optimised for performance.
Cons: Expensive, replacement often limited to the manufacturer or trusted third parties.

Things to Watch Out For

Battery Life Claims: Real-world usage may vary significantly from manufacturer estimates.
Temperature Sensitivity: Cold weather can reduce performance; lithium batteries are better suited for outdoor use.
Leakage Risk: Use quality brands to avoid damage from leaking alkaline batteries.
Compatibility: Some devices may require specific battery brands.
Counterfeit Batteries: Stick to reputable retailers or the original manufacturer.
Rechargeable Batteries: Generally not recommended as they may not provide sufficient power to the device and can give inaccurate readings on remaining charge

Recommended Battery Brands

Duracell: Reliable for alkaline and lithium formats.
Energizer: Known for long-life options like Energizer Ultimate Lithium.
Panasonic: Excellent for coin cells like CR2032 and CR2450.
Sony/Murata: Trusted for coin cell and specialty batteries.
Amazon Basics: Budget-friendly, good for low-power devices.

Conclusion

It’s always advisable to purchase batteries from reputable brands and trusted suppliers. Low-cost or counterfeit batteries often have a significantly shorter lifespan and may pose a safety risk, including a higher chance of overheating or fire, due to poor manufacturing standards.

In most cases, rechargeable batteries (unless built-in by the manufacturer) are not recommended for smart home devices. They often provide a lower voltage than required, which can lead to performance issues. Additionally, many sensors struggle to accurately detect the remaining charge in rechargeable cells, potentially leading to unexpected power loss.