Lithium batteries are everywhere - why do we need to store ours at ~50%? (and set auto-discharge at X days?)

[atxmavic]

I'm just asking the question ... My Riyobi/Hitachi tools do not require/recommend a particular storage level, nor do they auto-discharge... Nor does the UPS for my PC, nor my 'pocket charger/booster battery' for my smartphones, nor my iPad/Tablets, DSLRs/flashes... the list goes on especially nor does any of the Teslas... I'm just asking the question/s - what makes us special?

 

[elroy]

Just watched an iPhone 8 plus go up in flames in the cabin of a plane. Capacity much smaller than a MA battery. Less energy has a better outcome. I guess it has more with travelling to do. I never discharge my Makita LX batteries. But I Dont travel with them.

 

[PhantomFandom]

I'm just asking the question ... My Riyobi/Hitachi tools do not require/recommend a particular storage level, nor do they auto-discharge... Nor does the UPS for my PC, nor my 'pocket charger/booster battery' for my smartphones, nor my iPad/Tablets, DSLRs/flashes... the list goes on especially nor does any of the Teslas... I'm just asking the question/s - what makes us special?

I'll preface my comments with "I am NOT a battery expert", but I'll comment from my understanding of Li Ion batteries in general. LiPo are just one type of Li Ion battery.

• The recommendations for taking care of your drone batteries are equally valid for your phone, tablet, electric drill, and yes even that Tesla. The difference is that we are accustomed to replacing our phones every two years, and we expect our power tool batteries to gradually lose power over time and eventually just die. You don't want that with a drone because it needs to stay in the air, and the batteries are expensive to replace.
• The recommendations for storing a battery at in intermediate value applies to all of these devices. Don't keep it fully charged and don't let it go completely dead.
• A Tesla (or any other electric/hybrid vehicle) has very sophisticated battery management systems which keep the battery in a conditioned state to maximize its useful life. No one wants to replace their EV battery every two years!
• There are studies (and as a nerd I've read a few) about the effects of charge cycles on batteries. Keeping a battery at 100% charge is one of the worst things you can do to it. The battery life will be appreciably shortened. So what do most people do with their cell phones? They use them all day, then get home and put them on the charger all night.
  So the battery reaches full charge and then is kept at full charge for the rest of the night with a trickle charge. TERRIBLE for battery life. If you were to instead only charge your cell phone to 70% instead of 100% your battery would last probably three to four times longer! Charging it to 80% would extend your battery life by two to three times.

So why are drone batteries different? They really aren't different. It's about expectations and needs. You don't want your drone to fall out of the sky after 3 minutes and you don't want to replace the batteries every year or so. Treat them properly and they will last longer.

 

[old man mavic]

I'll preface my comments with "I am NOT a battery expert", but I'll comment from my understanding of Li Ion batteries in general. LiPo are just one type of Li Ion battery.

• The recommendations for taking care of your drone batteries are equally valid for your phone, tablet, electric drill, and yes even that Tesla. The difference is that we are accustomed to replacing our phones every two years, and we expect our power tool batteries to gradually lose power over time and eventually just die. You don't want that with a drone because it needs to stay in the air, and the batteries are expensive to replace.
• The recommendations for storing a battery at in intermediate value applies to all of these devices. Don't keep it fully charged and don't let it go completely dead.
• A Tesla (or any other electric/hybrid vehicle) has very sophisticated battery management systems which keep the battery in a conditioned state to maximize its useful life. No one wants to replace their EV battery every two years!
• There are studies (and as a nerd I've read a few) about the effects of charge cycles on batteries. Keeping a battery at 100% charge is one of the worst things you can do to it. The battery life will be appreciably shortened. So what do most people do with their cell phones? They use them all day, then get home and put them on the charger all night.
  So the battery reaches full charge and then is kept at full charge for the rest of the night with a trickle charge. TERRIBLE for battery life. If you were to instead only charge your cell phone to 70% instead of 100% your battery would last probably three to four times longer! Charging it to 80% would extend your battery life by two to three times.

So why are drone batteries different? They really aren't different. It's about expectations and needs. You don't want your drone to fall out of the sky after 3 minutes and you don't want to replace the batteries every year or so. Treat them properly and they will last longer.

@PhantomFandom a wonderful answer to the Ops question,not really anything to add the batts that we use are along with the props one of the most important,parts on our UAVs there for looking after them as you said ,will not only make them last longer but also improve the chances of a successful flight

 

[Mr. Salty]

I have a number of lithium-ion powered lawn tools made by Ego, including a lawn mower, snow blower and weed trimmer. Ego's batteries also have an auto-discharge function that kicks in if they haven't been used in a certain length of time, even if they're on the charger.

And by default, Tesla batteries do not charge to 100% in order to maintain them at optimum health for as long as possible.

 

[tcope]

Many of the devices you mention are discharged often. So those are not the same. My laptop has a setting to charge to 60 percent while plugged in in order to preserve the battery. As far as other devices, leaving at 100 percent over time will tend to harm the battery but, as mentioned above, most of those devices are used often and in other cases, the manufacture does not really care.

 

[Kilrah]

I'm just asking the question ... My Riyobi/Hitachi tools do not require/recommend a particular storage level, nor do they auto-discharge... Nor does the UPS for my PC, nor my 'pocket charger/booster battery' for my smartphones, nor my iPad/Tablets, DSLRs/flashes... the list goes on especially nor does any of the Teslas... I'm just asking the question/s - what makes us special?

Nothing, the others just don't care about advising you about best practices for getting the longest life from your batteries, and are happy to sell you replacement batteries/devices instead when they die quicker.
You also don't typically leave a phone/iPad/Tesla at 100% in storage for months, you use it.
Also aircraft batteries are put under a load that few other devices do, so the effects of poor handling become noticeable much quicker, potentially quick enough that people would complain and ask for free replacements so manufacturers have interest in enforcing optimal storage conditions.

On a UPS it's obvious that the batteries need to be kept charged otherwise the whole device is pointless, but then they typically use lead-acid batteries which unlike lithium ones DO want to always be charged and are thus better suited for that application.

 

[Unsub]

I'm just asking the question ... My Riyobi/Hitachi tools do not require/recommend a particular storage level, nor do they auto-discharge... Nor does the UPS for my PC, nor my 'pocket charger/booster battery' for my smartphones, nor my iPad/Tablets, DSLRs/flashes... the list goes on especially nor does any of the Teslas... I'm just asking the question/s - what makes us special?

It is better to be safe than sorry, I also do rc crawlers and while I never personally flow all the battery rules all the time and have gotten lucky, I have also see bbn others who have had thier batteries burst, destroying not only thier rc but also thier garages, houses, or thier actual cars if stored inside.

 

[siriuset]

Hello all. New member here. How does one discharge the batteries without flying and running them down? I anticipate being called away on a trip, wanting to bring my MA, and not having the time to fly the drone just to discharge the batteries.

 

[Deleted member 94047]

Hi siriuset, welcome! You can let the MA hover for a while in the backyard or equivalent till the batteries go down to about 60%, that is what I do I discover I have a full battery and won't be able to fly. Now, some times, it is understandable that you won't even have the opportunity or time to do that. Luckily DJI batteries are intelligent in that they will be able to auto discharge right about 7 days after if they have been sitting unused. It is ok to rely on this smart feature once in a while as long as you don't make a habit of it. Bottom line, discharge batteries to about 60% manually if you can, if you can't do that, the auto discharge function will take care of it for you. Also, don't forget it is equally bad to let the batteries sit around on a low voltage for a long time. Try to store them charged at 30% - 60% of their capacity.

 

[siriuset]

Hi siriuset, welcome! You can let the MA hover for a while in the backyard or equivalent till the batteries go down to about 60%, that is what I do I discover I have a full battery and won't be able to fly. Now, some times, it is understandable that you won't even have the opportunity or time to do that. Luckily DJI batteries are intelligent in that they will be able to auto discharge right about 7 days after if they have been sitting unused. It is ok to rely on this smart feature once in a while as long as you don't make a habit of it. Bottom line, discharge batteries to about 60% manually if you can, if you can't do that, the auto discharge function will take care of it for you. Also, don't forget it is equally bad to let the batteries sit around on a low voltage for a long time. Try to store them charged at 30% - 60% of their capacity.

Sounds good. Thanks Doppler.

 

[John the Beast]

A Lipo bag is required at almost all airlines.

 

[msinger]

How does one discharge the batteries without flying and running them down?

The easiest way around this is by not charging the batteries unless you're sure you're going to fly. If you charge the batteries a handful of times a year and cannot fly, it's okay to let them auto discharge down to the storage level. The batteries will start to discharge after 10 days and will take an additional 1-3 days to discharge down to the storage level. Unless you're charging the batteries and not using them every week, it'll likely be more trouble than it's worth to manually discharge the batteries.

In addition to draining the battery by letting the Mavic Air run, you could also:

• Discharge the battery using a discharger like the Mavic Angel
  
  
• Connect the battery to the Battery Power Bank Adapter and connect the adapter to another electronic device (like your phone) to charge it (which will discharge the Mavic Air battery)

 

[msinger]

A Lipo bag is required at almost all airlines.

I don't know of any airlines that require LiPo batteries to be stored in LiPo bags. You should only need to cover the battery terminals. In addition to using a LiPo bag, you could also tape the terminals, cover the terminals with a battery cover, or put the batteries in a case/bag that has separate compartments for each battery.

 

[Pontoon-pilot]

This is a great topic.
Li-polymer and Li-ion a bit different. Li-po HV is what we have.
Lipos are great for rapid discharge and is used in most RC toys. Li-ion is for the phone, tablet, power tools and vehicles.
Most aftermarket lipo chargers have a simple function to "charge to storage", which is about 3.8 volt/cell.
Why doesn't our Mavic charger has that option?
Realistically when I am done flying the batteries are near dead, (1 out of the 4 bars). So I would like to change it to 2 bars assuming it is about 50%.
With the DJI supplied charger the only way to do that is to keep watching and checking... not the best option with 2-3 batteries.

PS: most better electric vehicles use li-ion packs with sophisticated thermal management; cooled and heated via a heat exchanger.

 

[jeplane]

A Lipo bag is required at almost all airlines.

No sir, this is incorrect.
However, spare batteries must be protected from damage and short circuit.
Source: https://www.faa.gov/about/office_or...fo/media/Airline_passengers_and_batteries.pdf

 

[MichiganMavic]

NO Bags are needed for the batteries.
Urban Legend
Old Wives Tale
Folklore...
Please read other threads on this.
*Back to topic

 

[fileophile]

I think I’ve wrecked a few Mavic batteries by believing that their “smart-charger” was actually smart enough to leave them in the charger for weeks. Why can’t the charger handle ideal storage charging/discharging. Put a button on it for “storage charge”?

 

[Kombucha]

I own an early Nissan Leaf and I have had a very long life with the original battery. This version of the Leaf has a setting I use called Long Life, which only charges to 80%. In addition, if we go away on vacation, we leave it at approx 50%. Others who full charge all the time see battery degradation.

So, treat it right and it will last. Or treat it rough and be able to afford a replacement.

 

[Dizzy1971]

I have a number of lithium-ion powered lawn tools made by Ego, including a lawn mower, snow blower and weed trimmer. Ego's batteries also have an auto-discharge function that kicks in if they haven't been used in a certain length of time, even if they're on the charger.

And by default, Tesla batteries do not charge to 100% in order to maintain them at optimum health for as long as possible.

I too have the E go products for my yard and those batteries really are excellent.