Battery life while in storage

[Nigpd]

I was watching a YouTube vid the other day, made by a pair of reputable American drone experts.

In it, they said that if a drone battery remains unused for 6 weeks, even though stored and kept at 50% charge throughout this period, it will be "toast"

Is this true?

 

[Chipdji]

I know guys that have kept their batteries at 50% and higher and stored them for much longer than three months and never had a problem. They may have just been lucky.

 

[Ron_Dog]

The "ideal" voltage for storing lipo's is 3.8 Volts per cell. I know DJI has a chip to put the cells into "storage mode",but I just fly my Inspire (hover it) until I hit 3.8 V per cell on the battery display, then land it! Works for me!

 

[Casey53]

I was watching a YouTube vid the other day, made by a pair of reputable American drone experts.

In it, they said that if a drone battery remains unused for 6 weeks, even though stored and kept at 50% charge throughout this period, it will be "toast"

Is this true?

Could be.

I charge them back up when I see the white LEDs drop to around 2 showing. Takes a while as I sometimes hit the battery check button which supposedly stops the 10 day discharge cycle I have set.

I've read where some who buy the Inspire 2 complain that out of the box the battery fails to charge while the spares bought still charge. May be the Inspire 2 sat too long in a warehouse before being sold and why they are DOA on being sold. Sales may be slowing overall though given the issues being seen like motors coming off and need for 3rd party riggings, prop matters, instability, camera tilt issues, random purple frames in video, stuck landing gear, firmware and software issues, etc. Local Best Buy has cut back on allotted DJI sales space too with fewer models overall.

Aside, my major brand cellular store doesn't stock the high-end (larger memory) iPhones and iPads due to the battery issues if they sit too long unsold. They told me to buy one at a local Apple store and then bring it to them for activation which I did. Odd part was although Apple store gave me my carrier's SIM card, it didn't work at the carrier store and they had to use theirs.

 

[BlueCollarSky]

As some one who has been using lipo batteries since their introduction into the RC world about 15 years ago I would say this is a load of bs. I have large lipos that have sat in storage for months on end and they certainly are not toast. Are you going to see a loss in performance in the battery over time whether it is in storage or getting regular charging cycles, yes but that loss is generally small. All that being said, all lipos are not created equally and a dud cell can show up even in expensive batteries that are supposed to have higher quality controls. But if you have had a battery for awhile and it has been performing putting it into storage for 6 weeks is not going to harm it. If it did all of us would be buying new batteries every spring.

 

[Steve@AerialImagesPro]

that's not only false but not logical. think about it, How long do you think batteries sit unused between the time they're made, then shipped to reseller, then eventually sold and shipped.

You'd never be able to sell anything with Lipo batteries. Remember just about EVERYTHING that is rechargeable these days has a Lipo battery, including your cell phone, tablet etc...

To me a statement like that by these guys on YT discredits everything they say.

 

[STKNRUD]

Ditto on it being BS. I’ve had 1-cell and 10-cell lipos in storage for a couple years. Lipos are cycle limited but not storage time.

 

[ajohnsonlaird]

While I agree it is normally BS, back a year or more, there was a bug in the DJI Inspire 1 TB48 then current firmware such that if you left the battery at storage charge over the winter months then it would enter the "automatic" discharge mode -- but it didn't know when to stop, so it would take the voltage down to zero (or close to), thus trashing the batteries. I have four TB48's that were toasted because of this bug. So it could be that that was the start of this "alternative fact."

DJI's alleged Customer Support refused to take ownership of the problem asserting 1) the batteries were puffed up and 2) they were now out of warranty. They were not persuaded by the fact that the batteries were not out of warranty when I put them into storage, and the reason they were puffed up was because the DJI "smart" firmware was dumb enough to over-discharge the batteries thus causing them to puff up. Sigh.

That said, in my experience with other aircraft, "normal" LiPo's, taken to storage voltage, will happily stay there for quite some time -- I have some that have been at storage voltage for more than a year or two -- I don't know the exact limits because none of mine (other than the TB48's) have ever been toasted by holding them at storage voltage for long periods (e.g. a year or more).

However, before I bring a LiPo that's been in storage for a long time back into service, I will charge it, then discharge it down to storage voltage a couple of times (I use the Hyperion SuperDuo that has this capability). I do this more to make sure that the LiPo will function (albeit under light load during the discharge cycle). I do have a honking great dummy load discharger that I can use if I really want to simulate flight loads and discharge at 50 - 80 Amps. My initial report on this topic (now three years old) is here. I still have all the original Lipos that I used for the tests and I've held them at storage charge for three years, so I plan to re-test them to see if their performance (capacity and discharge curves) have degraded by being at storage voltage for that long.

Hope this helps...
Andy

 

[STKNRUD]

Best study on lithium methods and practices. Worth reading and saving for reference when this question and others come up again.

How to Prolong Lithium-based Batteries - Battery University

 

[Eric Braun]

I have many batteries that aren't used much. I look at them from time to time and all are keeping their storage charge. When I pull some out to use, like some 6S 3300mAh for my new ViperJet, they perform fine. The largest "regular" batteries I have are 4 6S 10000mAh MR batteries. I haven't flown them in years, but when I needed to get my Turbo-Ace Matrix flying again, one of them worked fine. I assume the others are fine too. Just don't let them get really cold!

 

[STKNRUD]

I have many batteries that aren't used much. I look at them from time to time and all are keeping their storage charge. When I pull some out to use, like some 6S 3300mAh for my new ViperJet, they perform fine. The largest "regular" batteries I have are 4 6S 10000mAh MR batteries. I haven't flown them in years, but when I needed to get my Turbo-Ace Matrix flying again, one of them worked fine. I assume the others are fine too. Just don't let them get really cold!

I think you should read the article I referenced above. Cold is not the problem. Heat is.

 

[Eric Braun]

I think you should read the article I referenced above. Cold is not the problem. Heat is.

Right. Living in N. California I'm not thinking about that. Cold is a problem if fully charged. Capacity reduces with temp and a fully charged battery will go into an overcharged state if it gets too cold. But if at storage charge cold should be fine. Back in the day I left a bunch of fully charged batteries out in the car on a frozen night in Oregon. All of them died. Learned my lesson.

 

[STKNRUD]

Since you live in California, I could think of a lot of 'nasty' replies but I am going to try and avoid it. Just kidding. I escaped CA four years ago.

 

[Eric Braun]

Since you live in California, I could think of a lot of 'nasty' replies but I am going to try and avoid it. Just kidding. I escaped CA four years ago.

It's a beautiful place and I live in some of the most beautiful. So I won't be baited...

 

[The Editor]

Ditto on it being BS. I’ve had 1-cell and 10-cell lipos in storage for a couple years. Lipos are cycle limited but not storage time.

Not false or BS but fact.
I have been over this in detail many times on the forum.

• Lipos loose capacity over time whether they are used or not.
• How well they are stored governs their capacity loss over a time period
• Well stored packs will only deminish circa 1 - 2% over a 12 month period
• Poorly stored cells can lose up to 10% or more over the same period.

Yes, manufacturing date has a influence on the capacity remaining in a pack.
Lipo cells start loosing their ability to take a full charge/capacity from the moment they leave the production line, whether they are used or not. In fact, the very article you link to highlights differing capacity loss over a year at 40% charge at differing temperatures of storage with the worse being a 25% loss of capacity over a 12 month period.

These are facts and just a well documented physical nuance of Lithium Polymer cell chemistry/technology.

 

[Casey53]

Don't forget that the DJI Intelligent Batteries have circuitry to drain (Kill?) them. They are not your generic hobby shop RC Li-Po battery that is sans the draining circuitry so most Li-Po battery storage information is invalid due to the DJI intelligent electronics (ahem!) part being within them.

When mine get down to two LEDs, they go back on the charger. Rather do that than to let them drop into the too low of voltage range to make them unseen by the charger and becoming trash can food.

 

[Lesmess]

Don't forget that the DJI Intelligent Batteries have circuitry to drain (Kill?) them. They are not your generic hobby shop RC Li-Po battery that is sans the draining circuitry so most Li-Po battery storage information is invalid due to the DJI intelligent electronics (ahem!) part being within them.

When mine get down to two LEDs, they go back on the charger. Rather do that than to let them drop into the too low of voltage range to make them unseen by the charger and becoming trash can food.

 

[licensed pilot]

I was watching a YouTube vid the other day, made by a pair of reputable American drone experts.

In it, they said that if a drone battery remains unused for 6 weeks, even though stored and kept at 50% charge throughout this period, it will be "toast"

Is this true?

Not my experience. I should add I store my batteries indoor at room temp, NEVER let them sit outside in hot or cold temps, and they rarely go over a month before flight. I also use an Angel device to deep cycle every 25 or so uses.

 

[The Editor]

I was watching a YouTube vid the other day, made by a pair of reputable American drone experts.

In it, they said that if a drone battery remains unused for 6 weeks, even though stored and kept at 50% charge throughout this period, it will be "toast"

Is this true?

I would question these two clowns reputability with a comment like that and go as far as to say they have absolutely no idea what they are talking about.
They certainly do not understand lithium polymer chemistry and should not be disseminating erroneous and misleading information.

 

[Nigpd]

Are these two talking drivel again?