Battery Storage Help

[FlyingJello]

Hello, just got a Phantom 3 for Christmas and I read in the manual that it is best to keep your battery at 40-50% for storage.

I am only planning on flying my phantom 1-3 times per week and I want to make my battery last as long as possible.

I read that you shouldn't keep your battery stored at 100% for over 24 hours. I was wondering if I could pull the battery off the charger early when it reaches 50% (according to the third LED). I've already done this once and I put the battery in the drone to see if it was at 50% (it was). Now I'm wondering if this was bad for the battery, and should I have just charged it to 100% and then let it auto discharge? All help will be appreciated because I'm a noob

 

[alokbhargava]

If you are flying three times a week, you should not worry about leaving them at 100% charged.

In fact these batteries are intelligent batteries and automatically starts discharging to safe value in set number of days.

If you are not using them for long then yes you should take care that they don't discharge below 30-40%. That's why a periodic check may be required.




Sent from my iPhone using PhantomPilots

 

[FlyingJello]

Thank you for the response

So is taking it off the charger early not a good way to get the battery in it's desired 40-50% range? Should I just stick to the auto discharge?

 

[alokbhargava]

Yes it's safe to rely on auto discharge.


Sent from my iPhone using PhantomPilots

 

[Quamera]

Thank you for the response

So is taking it off the charger early not a good way to get the battery in it's desired 40-50% range? Should I just stick to the auto discharge?

I have not even taken possession of my P4 yet but to see the maximum life of LiPo batteries in general you should avoid 4 things, keeping them near full charge or discharged, cycling them unnecessarily and heat. So taking them off the charger at 50% should be better than charging them right up and then letting them auto discharge.

Obviously its perfectly safe to allow the auto discharge to do its thing and far better than keeping them at 100% but that's just another cycle that you can never use again. The system is made to be almost foolproof but with a small amount of extra attention you can improve on it and extract the maximum life from your batteries.

For those of us that are old enough to remember the old NiCd batteries that had a "memory" and it was important to fully charge and completely discharge them to keep maximum capacity, you can forget all that, no lithium chemistry battery that I know about has a "memory".

 

[FlyingJello]

I have not even taken possession of my P4 yet but to see the maximum life of LiPo batteries in general you should avoid 4 things, keeping them near full charge or discharged, cycling them unnecessarily and heat. So taking them off the charger at 50% should be better than charging them right up and then letting them auto discharge.

Obviously its perfectly safe to allow the auto discharge to do its thing and far better than keeping them at 100% but that's just another cycle that you can never use again. The system is made to be almost foolproof but with a small amount of extra attention you can improve on it and extract the maximum life from your batteries.

For those of us that are old enough to remember the old NiCd batteries that had a "memory" and it was important to fully charge and completely discharge them to keep maximum capacity, you can forget all that, no lithium chemistry battery that I know about has a "memory".

Thank you for the info! Now I can charge my battery without worries

 

[HawkeyeDave]

I have not even taken possession of my P4 yet but to see the maximum life of LiPo batteries in general you should avoid 4 things, keeping them near full charge or discharged, cycling them unnecessarily and heat. So taking them off the charger at 50% should be better than charging them right up and then letting them auto discharge.

Obviously its perfectly safe to allow the auto discharge to do its thing and far better than keeping them at 100% but that's just another cycle that you can never use again. The system is made to be almost foolproof but with a small amount of extra attention you can improve on it and extract the maximum life from your batteries.

For those of us that are old enough to remember the old NiCd batteries that had a "memory" and it was important to fully charge and completely discharge them to keep maximum capacity, you can forget all that, no lithium chemistry battery that I know about has a "memory".

Sorry im adding to an old post but I was searching for some battery knowledge and came across this. Im one grew up with the old NiCd and was always taught to full charge and full discharge to get maximum life out of battery. Still learning about the LiPo's,,, My question after reading this is,,, if we don't have to worry about the memory of these new batteries yet I also read that you shouldn't let the battery get down to below a certain percentage. Can someone speak to this a little more.
Thanks,

 

[ChiefStealth]

Our Lithium batteries are multi-celled. We have to keep the individual cells "balanced", or very close in voltage. If any cell gets badly out of sync, it causes problems. If we have one cell out of sync, and we discharge the whole pack too much, there is a chance that the weak cell could be damaged beyond repair. That is why we don't do the 100% discharge-recharge thing like we did with Ni-Cads.
Our Ni-Cad packs were rated more on their amp delivery. Li-Pos are rated more on voltage. Draining Ni-Cads and keeping them real low until full charge for use was the proper process for achieving max amp delivery. That process has no benefit for voltage based Li-Pos. What is important is max voltage, min voltage, and cell balance.

 

[WilliamM]

Thank you for the response

So is taking it off the charger early not a good way to get the battery in it's desired 40-50% range? Should I just stick to the auto discharge?

I see some mixed advice here, Quamera is right on though. This is nothing wrong with pulling off the charger at the 50% mark, that's what most seasoned owners do for battery storage. It makes no sense at all, NONE. To fully charge a battery knowing it's going to self discharge before it's next use. That's wasting a battery's life for no good reason. The self discharge feature is meant as a back up plan in case you do fully charge a battery and don't get to use it. The setting range is between 1 to 10 days, the default is 10 (which is much too long). A better setting is something between 3 to 5 days.

 

[Quamera]

The best way to achieve maximum life and flying time from DJI LiPo batteries is to let them cool after flying to approximately 20% then charge to around 50% by removing manually from the charger as soon as the 3rd LED starts flashing or by setting the charging bank to storage. Just before flying top the batteries up to 100% and as the battery gains some age monitor the individual cell voltages so you are aware of cells that maybe loosing voltage faster than their 3 mates in each battery.

The auto discharge is an excellent fall back feature to avoid drastically reducing the life of the battery but you should never plan on using it and the 10 day default setting is a bit long. Keep the batteries away from high temperatures especially when fully charged and longterm storage should be in a cool, dry, dark area at about 30% to 50% charge.

 

[ChiefStealth]

I have one battery pack that will not auto-discharge. In the advanced tab of the battery tab in the settings within the DJI Go there is a message that says, in red text, bad cell. Its not real bad. There is one cell that is about .03 volt less than the highest cell. That's not a lot, but enough to keep the auto-discharge from working.
So, is there an approved method to discharge a battery pack other than the auto-discharge process? I could put the pack in the P3S and just let it run. Seems that would take a long time. Seems that would cause wear on motors. Maybe hook up a couple of 12volt car bulbs to slowly drain the pack? Ideas??

 

[WilliamM]

I have one battery pack that will not auto-discharge. In the advanced tab of the battery tab in the settings within the DJI Go there is a message that says, in red text, bad cell. Its not real bad. There is one cell that is about .03 volt less than the highest cell. That's not a lot, but enough to keep the auto-discharge from working.
So, is there an approved method to discharge a battery pack other than the auto-discharge process? I could put the pack in the P3S and just let it run. Seems that would take a long time. Seems that would cause wear on motors. Maybe hook up a couple of 12volt car bulbs to slowly drain the pack? Ideas??

I think if you want to discharge it more, just fly it a few feet above the ground. It shouldn't, take more than 15 or 20 mins.

 

[Quamera]

I have one battery pack that will not auto-discharge. In the advanced tab of the battery tab in the settings within the DJI Go there is a message that says, in red text, bad cell. Its not real bad. There is one cell that is about .03 volt less than the highest cell. That's not a lot, but enough to keep the auto-discharge from working.
So, is there an approved method to discharge a battery pack other than the auto-discharge process? I could put the pack in the P3S and just let it run. Seems that would take a long time. Seems that would cause wear on motors. Maybe hook up a couple of 12volt car bulbs to slowly drain the pack? Ideas??

You should put the battery in the AC and fly it at a low level over a safe area (even inside over a soft carpet but watch the drift because you will most likely be in atti mode) to see how the individual voltages hold up while flying. 30mV might not sound like much but it is a fair variation for a LiPo and it will probably grow under load, the Go app will throw up critical battery warnings and reduce the power output. Make sure you have the individual cell voltages displayed on the screen and fly it till the lowest one approaches 3.3 V and then fully recharge after it cools off.

If the cell is ok the voltage will balance out at 100% charge but always keep a watch on that particular cell because it is the most likely one to lag and let you down in the future. If that cell is still more than 30mV lower than its mates at full charge then you have an impending problem with it and the battery will probably fail soon. Keep a watch on the battery life indicator while you are using the battery, I don't know if it just works on the number of cycles or whether it is affected by battery warnings, cell voltage variations or other factors and it would be interesting to know.