


12V Battery Monitor
I’m paranoid about the 12V battery failures some people have reported with Subaru/Toyota EVs and other automakers, so I installed this ANCEL BM300 Pro battery monitor. It took less than five minutes to install.
It has notifications and alarms you can set if the battery drops below a certain voltage. It uses Bluetooth, so you need to be within about 10–15 feet of the car to get data, but it makes it easy to monitor your battery’s state of charge (SoC) through the app.
There will be times when we don’t drive the car for a few days, and I want to make sure telematics requests from the Subaru Connect app aren’t draining the 12V battery.
Other things I’m doing to avoid 12V battery drain:
- Disabled ACC mode
- Never use “Power On” mode (massive drain)
- Always use “Ready” mode if I’m sitting in the car waiting, so the traction battery charges the 12V battery