Any BLE HR strap should work. They all use a CR2032 coin cell that lasts several months. * The Wahoo chest strap is more comfortable and more convenient to do

Any BLE HR strap should work. They all use a CR2032 coin cell that lasts several months. * The Wahoo chest strap is more comfortable and more convenient to don and doff (it uses a snap at the front) and easier to change the battery. Main disadvantage is that the battery door is a known weak point (but you can 3D print a replacement) and can leak sweat inside, which causes galvanic corrosion on the circuit board. Also, it is sensitive to battery condition: silently stops transmitting, or transmits bad data when the battery is low. * The Garmin chest strap is less comfortable because the strap bunches up. Also, the plastic hook rubs on your ribs. It's less sensitive to battery condition and gives accurate low battery warnings, but you need a tiny torx (maybe a T1 or T2?) to replace the battery, which is annoying. On the other hand, the battery needs changing less frequently than on Wahoo's strap. I haven't tried Polar's chest strap, but it looks to be designed like Wahoo. Wahoo's arm strap (optical, like Apple Watch) seems to have less reliable data (like all optical straps). The battery only lasts ~6-8 hours, and requires a proprietary cable to charge. If you have any other fitness devices, like a bicycle GPS head unit or a GPS running watch, I would look for straps that are dual protocol (BLE / ANT+). ANT+ just works better than BLE: Easier pairing, lower energy consumption, fewer data dropouts.