How long do chest strap batteries actually last?

Coin-cell straps like the Polar H10 and Coospo H808S advertise 300–400 hours and reviewers generally see close to that with normal use. Rechargeable pods like the Wahoo TRACKR (~100 hours per charge) and the Garmin HRM 600 trade swap-the-battery convenience for USB-C charging. Reddit threads on r/wahoofitness and r/Garmin note that rechargeables eliminate the dead-battery-mid-ride problem older coin-cell straps had.