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Tello batteries Storage Mode

raulvolador

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Hi

I read a lot about 'Storage Mode' in LiPo batteries. For example, here

LiPo battery tutorial: The concise beginner guide - Droney Bee

Keeping it stored fully charged for long periods of time will degrade the cell from these increased chemical reactions, causing it to puff and/or have reduced efficiency at the bare minimum when you use it again

What is the ideal voltage then? Well, the very ideal voltage range for storage is 3.7V per cell. This is about 50% of the charge. Anything from 40% charge to 60 % charge should work well, however.
Many professionnal battery charges have an Storage Mode that works this way. Unfortunately our beloved tello does not have this mode.

As I tested a full charge into my Tello takes about 50 minutes from empty (20%) to 100% I present you:

My metod for Tello batteries Storage mode

  1. I use to fly my Tello until it reach 20% battery capacity warning.
  2. Inmediatly after a flight I wait a little until battery cools.
  3. Then I connect Tello to my 2.1 Amp 5 volts wall charger and set an stopwatch to 20 minutes
  4. I disconnect Tello from charger when the timer rings.
  5. That way I get an average 50% battery charging, ready for battery storage.
  6. The day I'm going to fly I connect Tello to charger and wait the time left for a full charge, usually it takes about 30 minutes.

EDITED DECEMBER 2018:

I was wrong. My twenty minutes method is dangerous for your batteries. Don't try it. You have to do nothing after flight. keep your batteries until you need charge them again.

More info forward this thread: Tello batteries Storage Mode

charger lipo storage mode.jpg
 
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Marshcat

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Been flying lipos for years. They should rest around 3.8v per cell. Thing is many drones cut about that voltage. So as to leave the battery safe for storage. My Parrot drones do that 0% is around 3.8. Thing is there is more capacity left. The pack can be safely used to 3.5v and 3.0v without destroying it though not recommended.
have you checked where 0% is voltage wise?
 

raulvolador

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Been flying lipos for years. They should rest around 3.8v per cell. Thing is many drones cut about that voltage. So as to leave the battery safe for storage. My Parrot drones do that 0% is around 3.8. Thing is there is more capacity left. The pack can be safely used to 3.5v and 3.0v without destroying it though not recommended.
have you checked where 0% is voltage wise?
Do you think that when battery shows 0% in Tello app it means battery is in Storage level ?

I didn't perform any voltage measure over Tello LiPos. I don't have any tinny connector suitable for that battery model.

Anyone did it ?
 
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Marshcat

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If you look at the battery it indicates as best as my bad eyes could see max charge 4.35v(hi power lipo), nominal voltage 3.8. Mine was low enough to self land and read 3.78v. OK for storage.

On my old DJI drone I can control the cut. I have it set for 2.75v I normally land around 3.5. The 2.75 cut is to allow for am emergency RTH. I will toast the pack to save the drone of course. Since most folks don't have knowledge of safe lipo handling the manufacturers are cutting the packs at storage to save us from ourselves. There's a good bit of flying time still in the pack.
 
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raulvolador

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Okay. Thanks a lot for your tips.

As soon as I can I´ll check what you say using a multimeter.

If you are right and at the end of the flight battery remains at storage voltage level (3.8 volts) I'll change my mind and I´ll not perform that 20 minute charge anymore.

Cheers
 
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raulvolador

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I performed some test.

After a succesfull Tello flight I landed at 20% battery warning.

Back at home I tested battery voltage. Voltmeter reading is about 3.71 volts

Searching this data table I realized battery capacity for that voltage is 15%. Voltage is below optimal storage level arround 3.8 volts.

After this I used my stopwatch method charging battery into Tello for 20 minutes. I used a 2,1 Amp wall charger. At the end voltimeter shows 3.85 volts (arround 55% capacity)

I still think that my 20 minutes charging storage method is good.


EDITED DECEMBER 2018: My previous voltimeter readings were wrong. Remaining voltage is about 3.80 volts, OK for storage.

Raul.

Lipoly Voltage vs. State of Charge 2S - 6S Packs.JPG
ez-peak plus charger + lipo 2 s battery/charging time to store
 
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Marshcat

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3.71/15% is just fine if you are using the pack often. Storage voltage is generally for long term non use. 3.97 is a bit high. If you fly Tello often the the 20% battery indication is just fine. Try cutting a 25 if it suits you better. A pack under 3.7 needs a charge and should never be left that way.

I ride an Ebike and routinely pull the packs to 3.5 to get the range i need but storage charge them immediately at that point. Lipos will also last much longer if only charged to 95%. Something to consider on hi $$ packs. Not a $20 Tello battery.
Still you are getting valuable knowledge on lipos and handling them.
 
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Dishnu

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does anyone know of a Battery checker for our Tello Batteries?
looking for a way to learn more about battery maintenance
 

raulvolador

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Dishnu

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vzr

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Hi

I read a lot about 'Storage Mode' in LiPo batteries. For example, here

LiPo battery tutorial: The concise beginner guide - Droney Bee



Many professionnal battery charges have an Storage Mode that works this way. Unfortunately our beloved tello does not have this mode.

As I tested a full charge into my Tello takes about 50 minutes from empty (20%) to 100% I present you:

My metod for Tello batteries Storage mode

  1. I use to fly my Tello until it reach 20% battery capacity warning.
  2. Inmediatly after a flight I wait a little until battery cools.
  3. Then I connect Tello to my 2.1 Amp 5 volts wall charger and set an stopwatch to 20 minutes
  4. I disconnect Tello from charger when the timer rings.
  5. That way I get an average 50% battery charging, ready for battery storage.
  6. The day I'm going to fly I connect Tello to charger and wait the time left for a full charge, usually it takes about 30 minutes.
I hope it helps.

Cheers.

View attachment 1534

Edited September 17: I have reviewed my data and changed the storage charging time from 30 minutes to 20 minutes. Sorry for the inconvenience.
Just FYI, Tello battery is Li-Ion (not Li-Po as advertised). Not big difference, but its easier for maintenance and You configured your charger incorrectly.
 

raulvolador

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You ar right, they are Li-Ion hight voltage (LiHv) bateries. Their nominal voltage is 3.80 v. and maximun voltage 4.35 v. while Regular LiPo has a 3.70 v. nominal voltage and a 4.20 v. maximun voltage.

Thanks.
 
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raulvolador

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Hi all,

I have to apologize to you. I was very wrong about Tello batteries Storage mode. In fact, my Twenty Minutes Method is a ********. It can damage your Tello batteries permanently. Please DO NOT TRY IT. :(

I realized my mistake after buying this rCharlance Tello Battery Charger

Amazon.com: DJI Tello Battery Charger,Rcharlance 3 in 1 Tello Battery Multi Rapid Charger with Digital Screen Intelligent Parallel Charging Hub Flight Battery Manager Fast Charging for DJI Tello Drone: Toys & Games

I performed my rCharlance charger this mod

Tello rCharlance charger external cable mod

This allows me accurately measure battery voltage. I was able to plug Tello Bateries into my old, reliable battery charger Thunder AC6 and perform several test.

Unfortunately Thunder AC6 charger is an old brand LiPo chager, unable to full charge Tello Bateries. EDIT DECEMBER 2019: I succesfully upgraded charger firmware to recognize LiOn bateries: RC Groups - View Single Post - IMAX B6 charger (original and clone) - open source firmware

That's becouse Tello mounts 3.8 volts LiOn-LiHv batteries. Tello batteries can be charged up to 4.35 volts, while standard LiPo are only charged up to 4.20 volts.

Luckily my old charger does have a LiPo Storage Mode that can be used with LiOn-LiHv batteries-

I was shocked when I realized Tello bateries was close near Storage voltage after a full flight and landing at 20% capacity indicator !

rcharlance thunder ac6.jpg

Summarized:

Yo have to do NOTHING after a succesfully flight, just keep bateries into your flight bag until the day you need to fully charge them again.

Ryze programmers, trying to save our batteries are showing fake capacity readings. When the app shows 20% capacity, voltage is 3.80 volts and true remaining capacity is 40%. When the app shows 66% capacity, voltage is 4.08 volts and true remaining capacity is 80% and so on...

I hope it helps.
 
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raulvolador

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3.71/15% is just fine if you are using the pack often. Storage voltage is generally for long term non use. 3.97 is a bit high. If you fly Tello often the the 20% battery indication is just fine. Try cutting a 25 if it suits you better. A pack under 3.7 needs a charge and should never be left that way.

I ride an Ebike and routinely pull the packs to 3.5 to get the range i need but storage charge them immediately at that point. Lipos will also last much longer if only charged to 95%. Something to consider on hi $$ packs. Not a $20 Tello battery.
Still you are getting valuable knowledge on lipos and handling them.
I agree with you. I should have read your post with more attention
 

dalefhome

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I performed some test.

After a succesfull Tello flight I landed at 20% battery warning.

Back at home I tested battery voltage. Voltmeter reading is about 3.71 volts

Searching this data table I realized battery capacity for that voltage is 15%. Voltage is below optimal storage level arround 3.8 volts.

After this I used my stopwatch method charging battery into Tello for 20 minutes. I used a 2,1 Amp wall charger. At the end voltimeter shows 3.85 volts (arround 55% capacity)

I still think that my 20 minutes charging storage method is good.


EDITED DECEMBER 2018: My previous voltimeter readings were wrong. Remaining voltage is about 3.80 volts, OK for storage.

Raul.

View attachment 1543
ez-peak plus charger + lipo 2 s battery/charging time to store
Hi
The Tello battery is a lihv 4.35v not lipo 4.2v What do you recommend ending a tello flit at.
Indicated. 10%?
My tello lands at 9% to 10% and powers off.
 

raulvolador

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Hi
The Tello battery is a lihv 4.35v not lipo 4.2v What do you recommend ending a tello flit at.
Indicated. 10%?
My tello lands at 9% to 10% and powers off.
This is a very controversial matter, but this is my opinion:

If you land in time, lefting your batteries at 15%-20% of their capacity they will be ok for a long time storage.
If you fly until your batteries are fully depleted, you should charge them a bit until they reach 3.85 volts optimal storage point. You can use a smart charger, like me, or your regular charger carefully timing.
Take into account the most important advice is not let your batteries fully charged for long periods as they will degradate a lot.

Best regards

Raul.
 
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dalefhome

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This is a very controversial matter, but this is my opinion:

If you land in time, lefting your batteries at 15%-20% of their capacity they will be ok for a long time storage.
If you fly until your batteries are fully depleted, you should charge them a bit until they reach 3.85 volts optimal storage point. You can use a smart charger, like me, or your regular charger carefully timing.
Take into account the most important advice is not let your batteries fully charged for long periods as they will degradate a lot.

Best regards

Raul.
Thank you for responding. I believe my tello battery’s are at about 3.8V when the tello lands with 10% remaining. I will Verify next time I fly. After the tello self lands I will quickly remove the battery and measure the voltage.
Thanks again for responding.
Dale
 

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