Battery Discharge while Stored?

[nutsnbolts]

So I had 4 batteries charged 100% and haven't flown it for 4 to 5 days due to inclement weather. Is it normal that it discharges that quickly?

I flew today with a 100% charged battery that was attached to my spark and when I went into my case to pull out another one, 2 out of the 3 that was in the case was discharged to around 75%.

Is this normal? I guess I have to check my batteries next time before going out.

 

[clouseau]

So I had 4 batteries charged 100% and haven't flown it for 4 to 5 days due to inclement weather. Is it normal that it discharges that quickly?

I flew today with a 100% charged battery that was attached to my spark and when I went into my case to pull out another one, 2 out of the 3 that was in the case was discharged to around 75%.

Is this normal? I guess I have to check my batteries next time before going out.

Yes, this is normal, I see this most often on my friends Sparks that have older batteries which have many flights on them. I believe the batteries which have a higher % of either cell resistance or voltage tend to start discharging faster than the other batteries which have cells that are more equally balanced.

 

[nutsnbolts]

Yes, this is normal, I see this most often on my friends Sparks that have older batteries which have many flights on them. I believe the batteries which have a higher % of either cell resistance or voltage tend to start discharging faster than the other batteries which have cells that are more equally balanced.

These were new batteries. No older than 3 weeks old I would say and as I have numbered them I have rotated the use accordingly. Hmm...

 

[msinger]

haven't flown it for 4 to 5 days due to inclement weather

Is it possible that it was more like 10 days? The batteries will start auto discharging down to about 65% after idle for 10 days.

 

[Virtual1]

Spark batteries will automatically (and fairly rapidly) self-discharge to 75% for storage. This is a documented feature of the batteries, and IIRC it happens if the batteries go 10 days without use. (I could be way off on that day count) Pressing the button (even briefly to check battery level) will reset the counter. It's normal for batteries to get noticeably warm (like "just flew on this battery" warm) while they are self-discharging.

They do this because lipo batteries degrade (chemically) when left at full charge for an extended time. The most common symptom you see from this is battery swelling. (common on laptop computers that spend most of their time connected to their power pack and thus keep their batteries at 100%) I ran across the "storage voltage" table for lipo awhile ago but don't recall the numbers exactly, it's not a very big drop, something like 0.15v or so. Discharging them to safe storage voltage improves their life expectancy and should practically eliminate the risk of storage swelling.

BTW, you can see how many times a battery has been recharged by checking the aircraft status in the Go4 app. Useful to tell if you have a battery getting a lot more (or a lot less) use than the rest.

 

[nutsnbolts]

Spark batteries will automatically (and fairly rapidly) self-discharge to 75% for storage. This is a documented feature of the batteries, and IIRC it happens if the batteries go 10 days without use. (I could be way off on that day count) Pressing the button (even briefly to check battery level) will reset the counter. It's normal for batteries to get noticeably warm (like "just flew on this battery" warm) while they are self-discharging.

They do this because lipo batteries degrade (chemically) when left at full charge for an extended time. The most common symptom you see from this is battery swelling. (common on laptop computers that spend most of their time connected to their power pack and thus keep their batteries at 100%) I ran across the "storage voltage" table for lipo awhile ago but don't recall the numbers exactly, it's not a very big drop, something like 0.15v or so. Discharging them to safe storage voltage improves their life expectancy and should practically eliminate the risk of storage swelling.

BTW, you can see how many times a battery has been recharged by checking the aircraft status in the Go4 app. Useful to tell if you have a battery getting a lot more (or a lot less) use than the rest.

This is good to know. Thanks for the additional info.

 

[OldBlueHeron]

You can also set in how many days you would like them to discharge. All of this information is available in the manual. Required reading.

 

[Virtual1]

You can also set in how many days you would like them to discharge. All of this information is available in the manual. Required reading.

Hmm I may have missed that, but I have a searchable copy here I can check. (I've got version 1.2 of the manual in PDF format) I see on page 27 ("DJI Intelligent Flight Battery Functions" section) it does nail down the numbers, 10 days and down to 65-70% it looks like. I don't see anything though about adjusting those 10 days. Is it somewhere else in the manual? If they overlooked it in my version, could you clue me in to how to do this? I like to know as much about my gear as possible and that sounds like it could be useful. (we actually do flies every other Wednesday indoors here so that's 14 days... I'd like to dial my timer up to say 20 days so it quits trying to needlessly discharge my batteries twice a month) TIA

 

[nutsnbolts]

Hmm I may have missed that, but I have a searchable copy here I can check. (I've got version 1.2 of the manual in PDF format) I see on page 27 ("DJI Intelligent Flight Battery Functions" section) it does nail down the numbers, 10 days and down to 65-70% it looks like. I don't see anything though about adjusting those 10 days. Is it somewhere else in the manual? If they overlooked it in my version, could you clue me in to how to do this? I like to know as much about my gear as possible and that sounds like it could be useful. (we actually do flies every other Wednesday indoors here so that's 14 days... I'd like to dial my timer up to say 20 days so it quits trying to needlessly discharge my batteries twice a month) TIA

If I understand this as well you can press the button and it resets the days.

 

[Virtual1]

If I understand this as well you can press the button and it resets the days.

Yep I heard about that already. (not sure where they found that info at though?) And that's what I'm doing now, once a week opening up the case and jogging the buttons. But my memory's pretty poor and I miss it about as much as I remember it. I prefer things to work as desired rather than rely on the meatbag to cover for their deficiencies ("Leave computers to do things computers are good at, and let people take care of the things computers aren't good at.")

 

[nutsnbolts]

Yep I heard about that already. (not sure where they found that info at though?) And that's what I'm doing now, once a week opening up the case and jogging the buttons. But my memory's pretty poor and I miss it about as much as I remember it. I prefer things to work as desired rather than rely on the meatbag to cover for their deficiencies ("Leave computers to do things computers are good at, and let people take care of the things computers aren't good at.")

Yeah the whole "intelligent" batteries went over my head. . Not until I started seeing the batteries discharging and asking the questions did I realize the whole science behind it.

 

[msinger]

You can also set in how many days you would like them to discharge.

This is not possible with Spark batteries since that setting does not show in DJI GO.

 

[OldBlueHeron]

I apologize, I got that mixed up with the Mavic.

 

[nutsnbolts]

I apologize, I got that mixed up with the Mavic.

Ok good I though I was going crazy with my spark. I'll check out my mavic with this setting.

 

[Flyin2low]

Just top them off the day of flying to make sure.

 

[Kanehi]

It's advisable to charge the battery the night or day before flying to get maximum charge use.

 

[lasorey]

I always store the batteries at 60% more or less, and top them off just before leaving home.

 

[#BirdDog]

I always store the batteries at 60% more or less, and top them off just before leaving home.

Not a bad theory, but how do you do this? Only run your batteries down to 60% when flying? Or only partially charge them? Why take the time to partially charge them knowing they will burn down on their own if stored for more than 10 days. I like the idea of storing them like that just not sure how to pull it off. Right now I’m running five batteries, run them till auto land and fully charge them all at the end of the day. Honestly since I recently got my spark I haven’t had a ten day stretch where I went without flying. But I do the same thing with my Phantom batteries.

 

[lasorey]

Not a bad theory, but how do you do this? Only run your batteries down to 60% when flying? Or only partially charge them? Why take the time to partially charge them knowing they will burn down on their own if stored for more than 10 days. I like the idea of storing them like that just not sure how to pull it off. Right now I’m running five batteries, run them till auto land and fully charge them all at the end of the day. Honestly since I recently got my spark I haven’t had a ten day stretch where I went without flying. But I do the same thing with my Phantom batteries.

I only have 2 batteries atm and a smatree powerbank. When i know its the last flight i only charge till half. When you have more batteries it might be more difficult indeed. I dont know yet how im gonna do that. Sometimes i have a full battery sow i power up sparky and let it drain the battery, that will be a time consuming task with more batteries.