ECU battery discharge.
I have a M200XBL and during a flight the engine flamed out. On checking the ecu battery voltage it showed 0ma. I assumed the battery was at fault and replaced with a new battery.The fully charged 3800mah 2s Lipo battery, when connected but without switching the receivers on, discharged itself in 2 hours. I connected another fully charged battery and monitored it and observed it discharge from 99% charged to 75% in just 15 minutes. Has anyone experienced this or have an idea as to the cause?