Unexpected Auto Land at 1,100ft distance??

[Serpent]

This is classic of a dead or dying cell within the battery pack. The voltage looks good until a load is put on it.

Does anyone have experience or know if it's possible to disassemble the battery pack and replace just the faulty cells? Given the price of these things i'm looking at options.

 

[ATC Drone Flyer]

Does anyone have experience or know if it's possible to disassemble the battery pack and replace just the faulty cells? Given the price of these things i'm looking at options.

I would say the short answer is YES. . .

However, the long answer would be:
1.) Where are you going to source the replacement cells?
2.) Are you highly skilled / and have the manual dexterity to dissemble / reassemble one of those batteries?
3.) How are your soldering skills?
4.) Are you willing to work in close proximity of potentially volatile compounds (with a hot iron, sharp knife, etc.)?
5.) How much is your time worth?
6.) Will you have enough confidence in your repair job to fly your Phantom "NORMALLY" (whatever that might be)?

Being a veteran of one flyaway and several unexplained forced landings myself, I definitely feel your pain. My confidence in this platform has definitely been diminished over time. The only way I can bring myself to fly more than 10 feet high or 100 feet away is to pretend that the Phantom + Gimbal + GoPro + FPV Gear, etc. won't cost me well over $1000 to replace, if I never see it again. I likely have well over 200 flights under my belt at this point, in a vast variety of locations and environments. In order to continue to enjoy this hobby, I have adopted the following philosophy: "It's not a question of IF you will someday crash or experience a flyway or other unexplainable event, it's a question of WHEN". What goes up, must come down. It's a numbers game as far as I'm concerned, and we as humans cannot control 100% of the forces that influence whether these flying machines stay in the air or not. If we could, then no one would have ever lost their life flying on a commercial airliner. . .

 

[DB_Cooper]

I'm having the same problem. The battery indicates 30% to 40% left and suddenly I get the low battery warning and the Phantom starts to land. I have to gain control by flipping the S1 switch and manually bring it back to a clear landing spot. Lucky only minor hard landing. When I recover the Phantom the last light on the battery is blinking so the battery is discharged. This occurs with all 4 of my batteries. I haven't flown for 3 months before this started occurring (this week). The batteries were not stored in a cool space during storage (I live in the tropics) so maybe they were overheated? Also left fully charged during storage. Upgraded to firmware 3.08 batteries 2.0 On dry discharge (no prop load) everything works fine. Batteries have only been charged 11 times. I'll buy 1 new battery and see if the problem goes away.

Sorry for the double post. Twitchy finger.
Not sure if this is related to the OP problem but I solved my similar problem. When all else fails, read the user manual. Section 2.5 page 14. For long period storage the batteries should be only charged to 40% - 50%. Every 3 months they should be discharged to 8% and then recharged to 100%. If they are going back into storage then drop them back down to 40% - 50%.
To fix my problem I discharged all my batteries to 8% and then recharged them to 100%. I again discharged them to 20% and recharged to 100%. All 4 are now working correctly with full flight time and correct warnings for low battery at 19%. No panic drops in voltage and back to normal flights.
Might also be a good idea to check the charge level before buying a new battery at a dealer. If it's fully charged you probably shouldn't buy it. He hasn't read the manual either.

 

[msinger]

Every 3 months they should be discharged to 8% and then recharged to 100%.

Per the manual, you should discharge and charge all batteries at least once every 3 months. However, you should only do a full discharge (down to 8%) every 20 charges.

If they are going back into storage then drop them back down to 40% - 50%.

If you're running the latest battery firmware, the batteries will auto discharge to a safe level if they are stored for 10+ days. So, this one should take care of itself.

 

[ATC Drone Flyer]

Battery Firmware

If you're running the latest battery firmware. . .

I thought DJI back stepped the battery firmware because too many folks were bricking there $130 batteries :?:
I have six (6) batteries in total. Four (older ones) were upgraded successfully during that narrow window shortly after the update came out, the other two I acquired later, and are still running the previous firmware version, with no apparent way to update them. What gives?