Is it normal for the mini 3 pro batteries to drain when not in use? I always charge mine fully after each flight using the 3 battery charging station then put them in my case. It's been 2 weeks since my last flight and when I checked my battery levels all 3 were down to 3 lights instead of 4.
This makes it a bit difficult to just 'fly without planning ahead'

Disregard, found out it's normal.

Yes they do, and take a while to charge back as you've likely found out.

Normal? It's a must that the battery get drain when not in used. If it doesnt, your battery will explode. Lipo battery do not want to be storage at full. That is why dji battery will drain itself. These types of battery likes being about 60 to 70%. Keep them 100% charge and they will puff up like a balloon. Even explode. You do not want to see what happens when a lipo battery blows.

Hi there. Thank you for your inquiry. The DJI Mini 3 Pro Intelligent Flight Battery supports Auto Discharging Function. To prevent swelling, the battery automatically discharges to approximately 96% of the battery level when it is idle for one day, and approximately 60% when idle for nine days. It is normal to feel moderate heat from the battery while it is discharging. For more information you may visit the DJI Mini 3 Pro user manual on page 30 using this link https://dl.djicdn.com/downloads/ ... _Manual_v1.6_EN.pdf also other downloadables for the DJI Mini 3 pro for your reference here https://www.dji.com/mini-3-pro/downloads . Hope this helps. Thank you.

I'm not a fan of this system.  I have never had a lithium battery to swell on any other device that does not have this system, yet they all stay charged.  A good example of why this system sucks is there was a fire ab9ut half a mile down the road last night in a house.  Grabbed the drone to get some aerial photos/videos, but discovered that evej though my batteries were fully charged, I didn't even have 2/3 of a full battery.  Why does DJI feel the need to implement this system while no other lithium batteries I own do this?  I own a construction business and have MANY DeWalt tool batteries.  They all stay charged through summer and winter alike and I have never had a failure nor any swelling.

djiuser_vg8SLPlm4ayj Posted at 1-27 11:41
I'm not a fan of this system.  I have never had a lithium battery to swell on any other device that does not have this system, yet they all stay charged.  A good example of why this system sucks is there was a fire ab9ut half a mile down the road last night in a house.  Grabbed the drone to get some aerial photos/videos, but discovered that evej though my batteries were fully charged, I didn't even have 2/3 of a full battery.  Why does DJI feel the need to implement this system while no other lithium batteries I own do this?  I own a construction business and have MANY DeWalt tool batteries.  They all stay charged through summer and winter alike and I have never had a failure nor any swelling.

It only has to happen once, and it will not be a nice picture, trust me!
That is the reason why it is STRONGLY recommended not to charge LiPo batteries over 85% if you are not planning to use it for a longer period of time (anything above 2-3 days s long). It would be ideal to have it somewhere between 20-85% at all times, and with mobile phones that is not a big problem but with other devices it is not so easy.
Some of the batteries or chargers (like DJI) that you can buy today have a special microcontroller built in that slowly discharges the battery, and with it greatly reduces possible issues like explosion.
Regarding DeWalt tool batteries, I'm not sure if they use LiPo or NiMh batteries but I have Bosch blue line where its LiPo battery slowly discharges over time, but not so fast as DJI chargers does it.
Anyway this is really great decision what DJI did, but as you said it is a possible issue with spontaneus flights. That is the reason why I always have with me 20 000Mha fast charging Power Bank