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

[toad007]

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.

Yes, but cellphone batts seem to last 3 - 4 years, and I am not special with them ?

 

[PhantomFandom]

Hi everyone,
I do normally fly my Mavic and land with 20% remaining battery (battery level warning set up at 30%) most of the times which is 1 steady light. I flight the 3 batteries once a month.
My questions are:
- Is it too low leaving the batteries at 20%?
Could this affect the battery life span or cells?
- If I charge it back to the recommended storage level, would that consume one cycle?
Charging it back to 50%-60%, would be a pain and perhaps consuming a cycle. I do not want to be constantly checking out the batteries and that’s why I do not drain them completely and leave them at an appropriate percentage, or that’s is what I thought until I read this thread... ?
Thanks in advance and safe flights!!

No, that's fine as long as you check on them if you won't be using them for a few months.

- If I charge it back to the recommended storage level, would that consume one cycle?

No. A charging cycle is the equivalent of charging from 0% to 100%. Charging from say 20% to 50% would only use up a partial charging cycle.

So what you're doing is fine.

 

[PhantomFandom]

Yes, but cellphone batts seem to last 3 - 4 years, and I am not special with them ?

What you may not be noticing is that your cell phone battery decreases in "battery health" over time. If you get 18 hours on a full charge when brand new, you may only get 13 hours after two years of charging it every night to capacity.

 

[kensteele]

if you have 4 to 5 hours or even half-day to spend with your drone and only had 2 or 3 batteries, what would you do to keep them charged in the field to maximize your flight time for the day (because buying more batteries)? how would you do it?

 

[Davebassman88]

No, that's fine as long as you check on them if you won't be using them for a few months.

No. A charging cycle is the equivalent of charging from 0% to 100%. Charging from say 20% to 50% would only use up a partial charging cycle.

So what you're doing is fine.

Thanks a LOT for your reply. Really appreciate it!