How to discharge your Phantom battery?

Joined
Mar 23, 2014
Messages
168
Reaction score
27
Location
Finland
How you can discharge your Phantom battery? Can I use e.g. bulb and connect it to battery terminals?
 

msinger

Approved Vendor
Joined
Oct 30, 2014
Messages
31,499
Reaction score
10,559
Location
Harrisburg, PA (US)
Website
PhantomHelp.com
Last edited:
Joined
Mar 23, 2014
Messages
168
Reaction score
27
Location
Finland
Thanks! It should work with 3-6 cell battery.You use it with your Phantom3 battery?
 

msinger

Approved Vendor
Joined
Oct 30, 2014
Messages
31,499
Reaction score
10,559
Location
Harrisburg, PA (US)
Website
PhantomHelp.com
I've only tried it on Phantom 2 batteries so far. The connector is the same though, so it should work on a Phantom 3 battery.
 
Joined
Apr 9, 2015
Messages
314
Reaction score
69
Age
41
Is this necessary for the P3?? I thought the battery self discharges after 10 days anyway.
 

Meta4

Moderator
Staff Member
Premium Pilot
Joined
Jan 8, 2014
Messages
14,897
Reaction score
8,899
Flying is the best way to discharge but if that's not possible ...
Point 3 here should be useful .. the time to discharge is adjustable in the app
i-Sv5Wm9T-L.jpg
 

msinger

Approved Vendor
Joined
Oct 30, 2014
Messages
31,499
Reaction score
10,559
Location
Harrisburg, PA (US)
Website
PhantomHelp.com
Is this necessary for the P3?
In the Phantom 2 manual, DJI recommends completely discharging batteries every 20 charges. I don't see that in the Phantom 3 manual -- but, they do talk about completely discharging the battery for some reason.

Flying is surely the fastest way to discharge a battery. However, your Phantom might drop from the sky if it does not land itself in time when the battery is low. For that reason, I do not recommend anyone ever try to completely discharge a battery by flying the Phantom until the battery is in a dangerously low state. If you value your investment, you should always land at or before the battery reaches the low level.

Here are some safer ways to discharge a battery:
  • Per the Phantom manual, turn your Phantom on with the motors (and props) off and wait for it to shut off.
  • Sit your Phantom on the floor, attach some kind of weights to the landing gear (so it doesn't fly away), and run it until it shuts down.
  • Use a battery discharger (like I linked above) or the SmartPower charger (not approved by DJI either).
 
Last edited:
Joined
Dec 4, 2013
Messages
103
Reaction score
32
Location
Duluth, MN
You have a good point and good recommendations. It does state this in the Phantom 3 Smart Battery Safety Guidelines on page 3.

"Charge and discharge the battery completely once every 20 charge/discharge cycles. Discharge the battery until there is 8% remaining power or until it can no longer be turned on, then recharge it the the maximum capacity. This power cycling procedure will optimize battery life."

http://download.dji-innovations.com...igent_Flight_Battery_Safety_Guidelines_en.pdf
 

msinger

Approved Vendor
Joined
Oct 30, 2014
Messages
31,499
Reaction score
10,559
Location
Harrisburg, PA (US)
Website
PhantomHelp.com
Ah, good find. So, that's still a requirement with the P3 batteries.
 

msinger

Approved Vendor
Joined
Oct 30, 2014
Messages
31,499
Reaction score
10,559
Location
Harrisburg, PA (US)
Website
PhantomHelp.com

BigAl07

Administrator
Staff Member
Premium Pilot
Joined
Jan 5, 2015
Messages
7,031
Reaction score
5,885
Age
50
Location
Western North Carolina
The weather here in WNC has been down right crappy for days. This is only the 2nd time since I've owned the P3P that it hasn't flown enough for the "auto discharge" to come into play and I have it set to 3 days (I think 3) in the GO ap. Last night I opened the case and checked all (4) batteries and sure enough they registered around 60% - 65%. I am planning to fly some this evening and all weekend so I topped them off last night.

The AutoDischarge is pretty sweet.
 
Joined
Dec 6, 2016
Messages
116
Reaction score
12
Age
36
My battery has 35 cycles and it hasn't ever been calibrated.

I flew it down to 25% and left it powered without props.

I read that then let the battery die while ac powered.

It went to 0% and cells down to 3,3 volts.

Then I read that you shouldn't let it discharge below 8% or completely discharge until battery dies.

Waiting now battery to cool down and then charge to 100%.


Did I make a mistake when I discharged it completely down to 0%???

Lähetetty minun SM-G930F laitteesta Tapatalkilla
 
Joined
Mar 10, 2016
Messages
322
Reaction score
83
How you can discharge your Phantom battery? Can I use e.g. bulb and connect it to battery terminals?
That's what I do. I take a 50 Watt 12 Volt halogen bulb and let it drain the battery. Make sure to monitor the voltage and verify the state-of-charge percentage to prevent over-draining.
 
Joined
Dec 6, 2016
Messages
116
Reaction score
12
Age
36
My battery has 35 cycles and it hasn't ever been calibrated.

I flew it down to 25% and left it powered without props.

I read that then let the battery die while ac powered.

It went to 0% and cells down to 3,3 volts.

Then I read that you shouldn't let it discharge below 8% or completely discharge until battery dies.

Waiting now battery to cool down and then charge to 100%.


Did I make a mistake when I discharged it completely down to 0%???

Lähetetty minun SM-G930F laitteesta Tapatalkilla
Just charged the battery full.

I did put it in to AC to see did i kill it, but it seems good. All cells are @ 4.3 volts but dji go shows that batterys total capacity is "only" 4350mAh?? There is printed 4480mAh to the battery. It did show the same even before discharge so no change here.

When more and more cycles come and battery life gets worse does this total capacity decrease?

Lähetetty minun SM-G930F laitteesta Tapatalkilla
 
Joined
May 9, 2015
Messages
294
Reaction score
56
Age
70
Just charged the battery full.

I did put it in to AC to see did i kill it, but it seems good. All cells are @ 4.3 volts but dji go shows that batterys total capacity is "only" 4350mAh?? There is printed 4480mAh to the battery. It did show the same even before discharge so no change here.


When more and more cycles come and battery life gets worse does this total capacity decrease?

Lähetetty minun SM-G930F laitteesta Tapatalkilla
Yes - I think that's why the full discharge - to reset the counter which keeps track of the capacity which the charger puts into the battery from that known minimum level to fully charged. The reported capacity isn't updated in real time. I saw this when I had a battery fail 1 min into a flight - showed 96%. When I cycled it a couple of times, I noticed this lag. It's at least 30 seconds.
 
Joined
Sep 20, 2016
Messages
6
Reaction score
2
Age
47
I just bought my P3 about 4 days ago. I was wondering why after 3 minutes of hove my battery dropped to 86%. I just hovered it until 8% so hopefully before my flight in the morning that will help. I was worried something was wrong.
 
Joined
Oct 14, 2016
Messages
4,239
Reaction score
1,954
Age
65
Location
UK Brit living Latvia
Even DJI now say do not deep discharge - they have just not updated some of their manuals.

It is not possible for a discharge to accurately set a capacity - because to do that would need 0volts ... not 0% and then charge to full.
All it can do is reference to the initial charge point....

As lipo's age - they still have capacity, but what happens is the amount they deliver reduces due to increasing voltage drop .... use and age causes internal resistance to increase. You put a full charged battery into model - it initially delivers power required, but the higher internal resistance causes voltage drop faster than when it was new, as you fly, this voltage drop causes telemetry numbers to be lower and you see the display accordingly.
You could land the model, switch off and then check the battery - finding voltage significantly higher than what was displayed while flying. This leads to the apparent 'reduced capacity' claims.

This is universal across lipo use in models..... computers .... phones .....

Nigel
 
Joined
Jul 24, 2017
Messages
46
Reaction score
19
Age
43
Forgive the obvious novice questions, but when you guys say things like "monitor the voltage drop", how exactly are you doing this?
 

New Threads

Members online

Forum statistics

Threads
141,085
Messages
1,453,091
Members
102,910
Latest member
Porfirioreeves