How many days are your batteries discharge set at. After that number of days they automatically discharge for safe storage. So if they're set at 10 days and you charged them two weeks ago when you put it in it will show 100% as it's the last value stored from charging however given the length of time passed the battery has automatically discharged for safe storage. When you power it up, apply load, and everything calibrates you'll drop from the 40% no load storage level to critical quickly and require a hasty landing and a change of underwear.