Have you read the Intelligent Flight Battery Safety Guidelines from DJI? Lips hate the cold. Do not store them at less than normal room temps. Set to auto-discharge after a certain amount of days in the app if you leave them fully charged.
Sorry but this is VERY VERY wrong! If you are storing your Lipos for a prolonged period the absolute best environment for them is a colder storage - A fridge is ideal. You do not need to store them this way if you are going to use them again in a few days but for prolonged storage - say longer than 3 weeks cold is better to prolong their life.
Perfect conditions would be at around 3.86v per cell at approx 4 degrees. DJI packs are nothing special in the Lipo world and rely on a chemical reaction to release their energy the same as every other pack.
Packs degrade over time whether they are being utilized or not but if you want to slow down that degrading process then the best way to store them is as I stated above. However, the caveat being is you MUST bring them back up to room temp BEFORE charging.
Stores in this way your pack will only lose circa 2 - 6% of their capacity over a 12 month period. Storing Lipos in a warm environment can mean they lose up to 30% of their original capacity in a year! That means your 4,500mAh pack is only going to give you 3,150mAh and then you should only fly to 80% of that which mean 2,520mAh !
Also... yes, you should allow your packs to cool back down to ambient temp after a flight before you recharge them. Charging warm packs is not good for them.
I've actually posted on another thread here http://www.inspirepilots.com/threads/lipo-discharge-threshold.707/
as I'm curious to know how DJI have set their discharge/empty levels for their packs.