Battery Problem?

hangloose · Aug 11, 2016

Hello Folks,

In the interest of not losing my P3P, I need to know if it's time to replace my 2 batteries. I have two batteries. Battery one sits on the charger and the lights are out (not blinking green, 4 full bars). I put it into the phantom and the DJI app indicates that I have 98%. About 6 minutes into the flight (roughly) I get a low battery warning at 65% and need to return to home. Something doesn't seem right.

I marked this battery as being bad based on previous flights where I was able to fly about 7.5 minutes out and 7.5 minutes back to land safely with 30% left.

The second battery when I placed it in the P3P is showing 94% when I first start up so I'm not even attempting to take off at this point.

Do I need to replace both of these batteries about 1 year old now with 26 charges each? Seems like I'm doing something wrong.

Any advice, and thank you guys/gals

hangloose!

Mark The Droner · Aug 11, 2016

IMO you need to look at your cells for a balance problem. If there is a balance problem, try a deep discharge and see if that fixes it. If it doesn't fix it, retire the battery.

pomonabill220 · Aug 11, 2016

Do you store your batteries fully charged????
You said you let the batteries sit on the charger... that is a NO NO! "Battery one sits on the charger and the lights are out (not blinking green, 4 full bars)" They should be stored NO MORE than 60%.
How long between flights do you store your batteries?
Search for battery storage for tips on storing them correctly.

hangloose · Aug 12, 2016

Thanks guys. You've given me a place to start.

pomonabill220 · Aug 12, 2016

I hope you get your batteries figured out because storing them fully charged will REALLY kill their life.

hangloose · Aug 12, 2016

Battery #1, all of the cells looked even before I started a deep discharge by running it down in the vehicle with the props off. I'm recharging now. According to the manual I should I have done this about 6 cycles ago. I don't charge the batteries right after each use of the vehicle, but rather charge them prior to each use. I generally, and I say generally store them with the second bar blinking which should indicate about 30% left.

pomonabill220 said:
I hope you get your batteries figured out because storing them fully charged will REALLY kill their life.

I think the way that I typed my original message makes it definitely sound like I store them fully charged. I usually charge them either before flying or the night before. When they sit, they are at 2 bars, with one flashing. I hope that makes sense. I performed a deep discharge today for both batteries. I will charge them in the AM and try see if it makes a difference.

Also, the battery life indicator, indicated 90% battery life left.

pomonabill220 · Aug 12, 2016

I see now! Yes, it did sound like you left them sitting on the charger... sorry I misunderstood.
Storing them with bar #2 flashing is about right, although from what I understand (and I am NOT an expert by any means!) #2 flashing is, as you stated, about 30% and that is "recommended" by DJI for long term storage.

For short term storage, you don't have to take it that low, but about bar #3 flashing (~60%). Short term storage, from what I understand, is for greater than 2-3 days and less than a week.

If you are going to fly every other day for instance, I would imagine that letting it sit where you last flew and charging it before you fly would be just fine, no matter where the charge is. Just don't forget and let it sit there for very long.
Please someone correct this for all of us!

There is so much controversy on this subject that it gets very confusing!
I just tried to research all the different schools of thought and this is what I came up with.

pomonabill220 · Aug 12, 2016

Another thought.... how many flights have the batteries had?

pomonabill220 · Aug 12, 2016

Just being concerned and responsible about your batteries health means that you are diligent and want to make sure that you don't have problems due to batteries.
After all, without a battery, you have a rock! lol

hangloose · Aug 12, 2016

pomonabill220 said:
Another thought.... how many flights have the batteries had?

27 charges each.

pomonabill220 · Aug 13, 2016

Yeah... that is getting up there for these batteries!
Not too sure what others are getting, but I think 30-50 "cycles" is about all they are good for.
When you say 27 charges, is that 27 flights as well? and how far discharged (roughly) were they? 20 minutes/25 minutes/30 minutes flight time?

hangloose · Aug 13, 2016

pomonabill220 said:
Yeah... that is getting up there for these batteries!
Not too sure what others are getting, but I think 30-50 "cycles" is about all they are good for.
When you say 27 charges, is that 27 flights as well? and how far discharged (roughly) were they? 20 minutes/25 minutes/30 minutes flight time?

Good question on the number of flights. Is there a way to tell definitively how many flights I've logged? My general trend has been to run the batteries down to 30% and land in a single flight, but I'm sure there's been a few occasion where I might fly a short duration, land, and take off again. One message that I've seen pop up recently is something about the propulsion system being limited.