Please select Into the mobile phone version | Continue to access the computer ver.
Serious informations for ppl using p4 batteries on p4p
3014 11 2016-12-25
Uploading and Loding Picture ...(0/1)
o(^-^)o
Alexdroner
lvl.3

United Kingdom
Offline

I have done some experiments today after I successfully retrieve my p4p from last recorded GPS location back after a critical low power landing at 2km away 499meter high at 34%.

For both test I turned off the smart RTH and flew the whole flight with P-mode (all other setting was default). Btw I found out on and off does the same thing anyway read.

1st flight
Flew the p4p with the p4 battery, i flew it around and hover near me with a altitude of 120meters until 20%. After 20% I started accend to 220m right above my home point so If anything happen I can still land it. And this time the critical low battery warning come up at 17% and landing initiated (can not be cancel) but If I pull the stick up I can still hole its altitude and fly back.

2nd flight
flew it with original p4p battery, did the same thing as 1st flight, it is absolutely fine. critical battery warning appeared as expected at 10% and started landing.

What I learnt so far was, Even though the critical battery level set at 10%, the p4p will always estimate the battery/time left required for the drone to land safety depend on your height and possibly the distance. Once it went to landing mode due to critical low battery, it cannot be cancel. (like if it can be cancel and fly it with sport  mode, I might have a higher chance to fly the drone back.) This is not due to voltage drop, it is (I guess) programmed this way to prevent hard crash.  

The reason why with the p4p battery is fine and warning started as expect is because the drone knew that the 10% of the high capacity battery left can still land safely.

So why the old p4 battery cannot? It might because a p4 battery has 9% less capacity compare to the new p4p battery and since the p4p is designed and optimised for p4p battery. Basically the 10% battery left for p4 and p4p high capacity battery are different in term of mAh left. For p4 battery at 10% are for sure so much less mAh than p4p battery at 10%, so we can't depend on that setting as I believe safety will always override that critical battery level setting. If you were like 500meter up and a few hundred meter away I believe even with the original p4p battery, the critical low power will force you to land at above the pre-set setting.

If anything were wrong, please correct me. I believe it is very important to know specially for people with p4 batteries on their p4p. Just make sure with p4 batteries on p4p at 30% batteries level the drone has to be around you with a relatively low altitude. I understand why dji support told me the p4 batteries was not suggested on the p4p but keep saying it is compatible. Merry Christmas Guys=]  
2016-12-25
Use props
ePetLicensing.c
Second Officer
  • >>>
United States
Offline

VERY GOOD POINT!!!
2016-12-25
Use props
theGrindLab.com
Captain
Flight distance : 1375846 ft
  • >>>
United States
Offline

Yes. Very useful information.
2016-12-25
Use props
DJI Mindy
Administrator
Flight distance : 7 ft
Offline

Hello Alex, as for P4 battery, it will estimate the battery time left for safety RTH as well. Could you please clarify what's the value of the critical battery warning on your P4?
2016-12-28
Use props
Alexdroner
lvl.3

United Kingdom
Offline

The setting of the critical battery warning on the p4p is as default 10%. You mean that right Mindy?
2016-12-28
Use props
Mike-the-cat
Captain
Flight distance : 17725148 ft
  • >>>
New Zealand
Offline

Flying your batteries down to 10% is 1) leaving very little safety margin as the discharge current at that level is at threshold for safety. 2) if repeated will shorten your battery life. Be safe and not sorry. Ascending to 220m to 'be safe' Sorry, I do not get the logic of this. An ascent of the sort you describe is a high current drain manoeuvre and if you do this at 20%, you are asking for trouble.
2016-12-28
Use props
Alexdroner
lvl.3

United Kingdom
Offline

Mike-the-cat Posted at 2016-12-29 03:49
Flying your batteries down to 10% is 1) leaving very little safety margin as the discharge current at that level is at threshold for safety. 2) if repeated will shorten your battery life. Be safe and not sorry. Ascending to 220m to 'be safe' Sorry, I do not get the logic of this. An ascent of the sort you describe is a high current drain manoeuvre and if you do this at 20%, you are asking for trouble.

I just wanted to test how the program works is there any better way to do it? Like even at 20% I spend me be like 1.5% battery to climb up from 120m at 17% I already recieved the critical low power and landing, even though the critical battery warning set at 10%, this is the main thing I want to show. The system know how much battery needed for a safe landing, in here safe mean won't fall off the sky. I usually stop flying at 20% I understand it is not good for the battery, but isn't it, it is good to know that how the aircraft actually perform, if this kinda of case happen, if our estimate were wrong etc. PS I also looked up at the battery voltage, the warning is not due to the voltage drop, it was still like 3.66 at 20% when draining May be like 3.5v, if there is anything abnormal I would have landed quick.
2016-12-28
Use props
theGrindLab.com
Captain
Flight distance : 1375846 ft
  • >>>
United States
Offline

DJI Mindy Posted at 2016-12-28 02:56
Hello Alex, as for P4 battery, it will estimate the battery time left for safety RTH as well. Could you please clarify what's the value of the critical battery warning on your P4?

Are you saying when a (lower capacity) P4 battery is used with the P4P, that the quad will correctly calculate the percentage of the battery left? Or would battery life still be calculated based on the capacity of a higher capacity P4P battery?
2017-1-22
Use props
Alexdroner
lvl.3

United Kingdom
Offline

theGrindLab.com Posted at 2017-1-22 20:57
Are you saying when a (lower capacity) P4 battery is used with the P4P, that the quad will correctly calculate the percentage of the battery left? Or would battery life still be calculated based on the capacity of a higher capacity P4P battery?

The percentage of p4 batteries in p4p will shows correctly, basically for both p4p and p4 batteries same rule applied when you are extreme high like 500meters, the  programs will always automatically initiate the landing mode above your critical battery level, that s not meaning the battery is fault or anything just for safety the program always calculate the amount the battery left for a safe landing. During landing given you still have signal you can always push it up to stay attudlite and come back but safety is the most important. I fly responsibly now so that warning never really come up any more, as long as you stay like below 120meter most like no weird thing will come up. also don't fly until the battery level is getting low, always return from 50% if you doing a range test. Hope it help.
2017-1-24
Use props
theGrindLab.com
Captain
Flight distance : 1375846 ft
  • >>>
United States
Offline

Thanks. I started testing with P4 batteries yesterday, and everything seemed to work as expected.
2017-1-24
Use props
QiiFlight
First Officer
Flight distance : 2999472 ft
  • >>>
United States
Offline

Alexdroner Posted at 2017-1-24 03:39
The percentage of p4 batteries in p4p will shows correctly, basically for both p4p and p4 batteries same rule applied when you are extreme high like 500meters, the  programs will always automatically initiate the landing mode above your critical battery level, that s not meaning the battery is fault or anything just for safety the program always calculate the amount the battery left for a safe landing. During landing given you still have signal you can always push it up to stay attudlite and come back but safety is the most important. I fly responsibly now so that warning never really come up any more, as long as you stay like below 120meter most like no weird thing will come up. also don't fly until the battery level is getting low, always return from 50% if you doing a range test. Hope it help.

I would suggest using your battery voltage as the primary indication of what is going on with the battery. The percentage is a calculation that may or may not lag behind what is actually happening with the battery. The percentage is a good indication, but the battery voltage is a more specific indicator. I rely on both indications and have never had an issue.
2017-1-24
Use props
theGrindLab.com
Captain
Flight distance : 1375846 ft
  • >>>
United States
Offline

QiiFlight Posted at 2017-1-24 04:11
I would suggest using your battery voltage as the primary indication of what is going on with the battery. The percentage is a calculation that may or may not lag behind what is actually happening with the battery. The percentage is a good indication, but the battery voltage is a more specific indicator. I rely on both indications and have never had an issue.

Great advice! Thank you.
2017-1-24
Use props
Advanced
You need to log in before you can reply Login | Register now

Credit Rules