The BM1 is a WiFi-enabled battery monitor for 12V and 24V battery systems. It runs ESPHome and is intended for seemless integration into Home Assistant. This device it perfect to add to cars, trucks, heavy equipment, backup generators and lawn equipment, and is especially useful for equipment that will be stored during off-season. An on-board beeper is also configured to chirp if the battery voltage drops below a safe level for 12V or 24V lead-acid batteries, giving an audible warning. In addition to it’s primary function, the device provides a simple temperature sensor that is convenient for monitoring the environment.
Other similar devices rely on phone apps and a Bluetooth connection, and often proprietary closed-source software. WiFi allows for greater range and Home Assistant integration allows monitoring from any device and long-term data logging. No proprietary apps required.
The 3D-printed enclosure is made from ABS-GF (glass-reinforced ABS), and is resistant to high and low temperature environments.
Options:
- For added moisture resistance, please select the conformal coating option
- For added UV resistance, please select ASA-GF material option
- For a magnetic case instead of screw down tabs, please select the Magnetic case option
- For a longer wire, please select the 36″ wire option
Specifications
- Measurement Range: 6 – 28 Volts
- Operating temperature: -20° to +85° C
- Sample Interval: 30 minutes
- Sleep Current: ~300 uA
- Active Time: 45 seconds
- Active Current: 4 mA
- Average Current: ~400 uA
- WiFi Working Range: 150 m
- Enclosure Size: 64.5 mm x 42.5 mm x 18.5 mm
- Mounting Tab Width: 86.75 mm
- Mounting Tab Hole Spacing: 75.5 mm
- Mounting Tab Hole Diameter: 5 mm
- Enclosure Material: ABS-GF
- Wire length: 8″
Kyle –
Nice battery monitor for weekend sports car
A quality device that provides useful information. It’s a snap to install on a car battery, and just as easy to pair with ESPHome. I really like having battery statistics for my less driven vehicles.