battery problems

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HEY GUYS
Iam having issues with my 2 batteries , firstly they wouldnt charge then i pressed on button on battery and got charger to work , so i get 100% battery charge and 94% life so batteries seem okay in assistant software
when i start fight battery lasts about 30 sec - 1 minute tops and drops to 50-60% and has critically low battery level warning ,then system error.
i tried flying holding base on idle or low revs and battery seems okay but when i increase revs to high battery sign turns red even at 95% and drops rapidly to say 80% with critically low battery warning , i go back to idle battery sign goes back to green at say 70%
Batteries have only had approx 20 discharges and i havent used much over past 12-18 months as havent had time to try and fix problem.
Tried DJI help and they said to discharge battery to 0% and recharge to recalibrated battery ,but iam not so sure about taking battery that low , and i dont think this is problem , i have taken down to about 8- 10% so to try and get charger to work but have since worked out trick, i also tried a different charger and it had same result charger light stayed on green even when battery was 10%.

i have all latest updates so any info would be greatly appreciated on what i can do so i can do some flying again.
Thanks heaps in advance
Brad
IMG_5824.JPG
 
The asst software reports all is good. But it doesn't behave correctly in flight. This is with two batteries.

I would make sure all my contacts are super clean. It almost sounds like dirty leads on the aircraft. You might even check the lead wires and the solder points.

If that doesn't help, I don't know what else is left but a deep discharge as recommended by DJI. I've had my healthy batteries deep discharged down to 3%. And they are in great shape. Just sayin'
 
I know how it is to forget some basics - I recently had to ask for reminders how to use GPS mission on Ultraflight app! So you forgetting after a year that to charge you have to turn on the battery brought a chuckle to me...

Couple more questions first:

1) What was charge levels when you stored them?
2) What was charge level when you got them out 1-1.5yrs later?
3) How long did it take to charge them back up? And from what %charge to 100%?

First look says your #2 cell is probably almost fully discharged and without discharging to LESS THAN 8% BUT MORE THAN 4% you will have useless batteries.
 
I was having an issue with mine earlier today....

I might have figured out a way of bringing life back to the batteries.

I stored them at about 30% for winter (a little low) and now went to use them and was getting all the battery warnings possible. Low/invalid/non-dji battery.

I discharged them completely like stated above. I also uninstalled the batteries firmware/software and reinstalled it. It seems to have reset the timer.just a guess.. But my battery is working again and is also now reading 1 bar higher at a time.(adding to the percentage of life).my percentage of life was reading near 30% earlier today.

(only my second time cycling the battery since winter)

This is looking as to be a promising way for me to save money on dji lipos.
 
Since when did you have to turn the battery on to charge ?? That trick is for when you interrupt a battery charge or want to top up the battery, if the battery charger is showing green with full batteries then the battery isn't reporting itself as fully charged. Do a deep deep discharge down to as low as you can or until the battery won't power on and do a full charge but if you need to turn it on to charge then in my opinion the battery is faulty.


Sent from my iPhone using PhantomPilots mobile app
 
Since when did you have to turn the battery on to charge ??

THANK YOU FOR CORRECTING MY POST!

It has been well over a year since I used the crude dji power supply to charge my P2 batts! I had forgotten! My smart charger refuses to charge unless I physically turn on the batt first. Took me almost 45 minutes to even find the old pos ps. My bad. Thank you.
 
Aussie dude, I assume you are still alive and well down under? If so, and if you want further comment and ideas on your two batts, why not respond to the open questions? You MAY get some data that MAY be useful to reviving your batts....
 
Hi guys
Sorry i it has taken me so long to back on here , i keep forgetting until i want to go for a fly and cant as my batteries have issues . i will look into all the above comments and see what i can do ,and let u know
- i would have stored probably full ,as i didnt have info then that it was bad to do this
-i have tried to full discharge to 0% to reset as advised from DJI and maybe approx 30-45 min to charge but not sure
Thank you very much for all your help ,i really do appreciate it .
Brad
 
aussie dude, way off battery issue, but yesterday I came across a youtube by the seekers so proudly singing your National Anthem "I AM AUSTRALIAN."

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THEY BLEW ME AWAY!!!!!! Never in my life have I heard another country's anthem that was anywhere near as good as our good old USA one - until yesterday!

Gave me goose bumps absorbing it!!

Then they went off and did Dancing Matilda! DANG! Made me wish for a bit I was an aussie too!

Topped it off with one of your own but not so famous guys:
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Jolly Good Job Mate!
 
The asst software reports all is good. But it doesn't behave correctly in flight. This is with two batteries.

I would make sure all my contacts are super clean. It almost sounds like dirty leads on the aircraft. You might even check the lead wires and the solder points.

If that doesn't help, I don't know what else is left but a deep discharge as recommended by DJI. I've had my healthy batteries deep discharged down to 3%. And they are in great shape. Just sayin'

0% on the flight app is not actually 0% for the battery :) the smart battery only goes down to 10.4 volts then it automatically switches off. I've seen a lot of people landing at 20% or 25% some at 15% but that is just plain silly since the battery is smart and cuts down power before even close to damaging itself.

I would personally recommend all phantom fliers (starting from P2) to use their batteries to the limit of the application (DJI VISION / Litchi / anything).
 
0% on the flight app is not actually 0% for the battery :) t
True but that's too simple an explanation. The problem is not with the app. The problem is with cell balance and also with battery operating temperature.

The % report by the battery/app assumes somewhat balanced cells and a battery that's in a favorable operating temperature. If you have a single cell out of balance and overall voltage somewhat low, the cell may shut down and so will the battery. This is also true with a battery that is too cold (below 20 C) even if the cells are balanced. Some have called it "voltage lag" where a cell drops lower than one would expect due to it's low temperature.

So in summary, the percentage can sometimes be misleading. What's really important is the voltage - combined with a good balance of the cells and good temp of the battery. In other words, we should be sure to fly with healthy balanced batteries and we should be sure the batteries are not too cold.
 
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True but that's too simple an explanation. The problem is not with the app. The problem is with cell balance and also with battery operating temperature.

The % report by the battery/app assumes somewhat balanced cells and a battery that's in a favorable operating temperature. If you have a single cell out of balance and overall voltage somewhat low, the cell may shut down and so will the battery. This is also true with a battery that is too cold (below 20 C) even if the cells are balanced. Some have called it "voltage lag" where a cell drops lower than one would expect due to it's low temperature.

So in summary, the percentage can sometimes be misleading. What's really important is the voltage - combined with a good balance of the cells and good temp of the battery. In other words, we should be sure to fly with healthy balanced batteries and we should be sure the batteries are not too cold.

Great explanation !
 
aussie dude, way off battery issue, but yesterday I came across a youtube by the seekers so proudly singing your National Anthem "I AM AUSTRALIAN."

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

THEY BLEW ME AWAY!!!!!! Never in my life have I heard another country's anthem that was anywhere near as good as our good old USA one - until yesterday!

Gave me goose bumps absorbing it!!

Then they went off and did Dancing Matilda! DANG! Made me wish for a bit I was an aussie too!

Topped it off with one of your own but not so famous guys:
To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Jolly Good Job Mate!
Glad you enjoyed it mate
aussie dude, way off battery issue, but yesterday I came across a youtube by the seekers so proudly singing your National Anthem "I AM AUSTRALIAN."

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

THEY BLEW ME AWAY!!!!!! Never in my life have I heard another country's anthem that was anywhere near as good as our good old USA one - until yesterday!

Gave me goose bumps absorbing it!!

Then they went off and did Dancing Matilda! DANG! Made me wish for a bit I was an aussie too!

Topped it off with one of your own but not so famous guys:
To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Jolly Good Job Mate!
Glad you enjoyed it mate
 
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Hey Aus dude. I'm from Sydney and I fly in similar weather conditions. Weather does affect voltage (colder = less flight times). Keep the battery in your pocket if you want longer flight times during winter.

Anyways,
The only way to prevent the critical battery voltage warnings is to NOT max stick your throttle. I know its hard, but you need limit your throttle to 70% and no more. I've had 5 OEM DJI batteries that all had this issue before any of them reached the 40 cycle mark. What is happening is that DJI has set safety voltage thresholds in the firmware that if it falls under, it will auto land. When you give it max stick for a prolonged period, the voltage will drop heavily, especially if you are at max load (The PV2+ V2 is near its maximum payload). What makes this worst is the battery cell configuration - it uses a total of 6 batteries to make a 3 cell. This means there are 2 batteries in parallel to make 1 cell. It is harder to balance parallel. This can lead to a masked damaged/saggy cell which only manifests when you are airborne.

Since I'm satisfied with the firmware on the P2, I don't use OEM P2 batteries anymore and have preferred aftermarket batteries since.

On the contrary, you don't here of this problem in the P3 as the batteries are in the true 4S cell configuration. This means 1 battery = 1 cell and this means the readings are not masked and always true.

Just remember, the P2 has 3 months warranty and the P3 has 6 months.
 
I haven't flown my P2V in around six months. When I pulled the battery out it was at about 50% charge. I flew it for a bit and I was getting a "bad cell" warning as the battery ran low. I charged it for well over an hour and I'm getting only 50% charge... What do you guys think?

-slinger
 
You should have fully charged the battery before you tried to fly.

If the battery is not charging, it may be bad. As a last ditch attempt to save it, you might discharge it to below 8%, then fully charge it, then put it in the P2V and plug it into your desktop, bring up P2V Asst and check the cell balance. If it seems okay, you might exercise it cautiously for several flights and recheck it often to see how the balance is holding up. Up to you.
 

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