30r20 HRR 70% - low battery

Got in again before work and got straight into the 30r20 - battery on Suunto is low (screen getting dim - managed to last the session - hope it will last this lunchtime as well) also battery on my bluetooth speaker gone FFS - didn't drink any water on the drive in and I reckon that combined with the baby waking at 3:30am cost me the 0.3 seconds per 500m from the same session yesterday