Store the heart rate monitor (HRM) with at least one chest strap button unsnapped. When both are connected, the HRM is on and using the battery.
You’ll need to change the battery periodically. You can do so by using a quarter to open the battery door on the electronic tab with the Peloton logo. The heart rate monitor uses a 3V Lithium battery model number CR2032. You can pick up a replacement battery at your local drug or hardware store.
You can hand wash the chest strap by removing the electronic tab.