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Batteries & Chargers Discuss Li-P, Li-Ion, NiMh, Nicad battery technology and the chargers that juice 'em up!

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Old 10-04-2017, 02:48 PM   #1
Douglas Racer
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Default Lipos On Real Airplanes

I've been reading up on carrying lipos on the airlines and the rules seems to be none in checked luggage (obviously) and a max of 160Whr or 2 grams of lithium in carry on. Here's a link from FedEx for the calculations.

http://images.fedex.com/us/services/...ery_JobAid.pdf

Their example shows Mah per cell. Am I correct in saying a 3000mah 3S 11.1v battery would be 1000mah per cell? If so we can carry some pretty large batteries on an airline.

EG 22.2v 6S 5000mah A fairly large battery.

Whr=22.2x5000/1000=111Whr
Lithium=5000/1000/6x0.3x6=1.5grams

I know there are restrictions of max two batteries between 100Whr and 160Whr

Are my calculations correct? Any comments? Thanks.

PS Yes, maybe I should have said full size rather than real airplanes in the thread title.
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Old 10-04-2017, 04:49 PM   #2
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No, a battery connected in series adds the individual cell voltages together but not the mah rating.

A 3000mah 3s 11.1v battery would have 3 -- 3000mah batteries connected in series.

3 -- 1000 mah cells connected in parallel, would have a 3000 mah ability but only 3.7v.
-------------------------------

FedEx's paper is strange, the left side says;
How to calculate Watt Hours,

Then they say MAX lithium per cell & MAX lithium per battery ?

The calculation is for Watt Hours

FedEx's information, would show that a 5400mah capacity per cell is the largest allowed, and a maximum of a 5s battery.

3.7 X 5.4 =19.98Wh
18.5 X 5.4 = 99.9Wh
---------------------------
The right side is about max lithium
The numbers there would show a max cell capacity of 3.3 Ah or 3300mah
1g / 0.3 = 3.333 amp hour, basicly a 3300mah cell
And since there is a max of 2 grams per battery

A 2s 3300 7.4v battery would be the largest allowed.

Typical regulations, one side can't agree with the other.


I hope research on the new "glass film battery" proves out what they think it will, 3x the capacity and fireproof.

Dave R, KI7MTA Proud PGR rider.
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You become a master at repair.
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Old 10-07-2017, 03:50 AM   #3
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Originally Posted by Douglas Racer View Post
Their example shows Mah per cell. Am I correct in saying a 3000mah 3S 11.1v battery would be 1000mah per cell? If so we can carry some pretty large batteries on an airline.
No sir that is not how it works.

Series circuit rules like a 3S Lipo
  • Current remains the same
  • Voltage and power adds.

So your 3S batteries are 3 cells in series of whatever Amp Hour capacity specified.
  • Parallel circuit rules.
  • Voltage remains the same
  • Current and and power adds

So if you want more capacity than a single LiPo is rated means you would add more batteries in parallel. Example let's say you use 3S 2000mah, but you need 3S @ 4400mah, you would use 2 batteries in parallel.
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Old 10-07-2017, 08:34 PM   #4
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Ok Thanks

I didn't know the Mah rating was per cell. I see that the lithium is more restrictive anyway. You can carry batteries up to 160 Whr but you are restricted to two. Most of my batteries other than my Trex are 3 cell. I figure then I could carry up to a 2200mah 3S then on the lithium restriction.
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Old 10-07-2017, 09:56 PM   #5
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Originally Posted by Douglas Racer View Post
Ok Thanks

I didn't know the Mah rating was per cell. I see that the lithium is more restrictive anyway. You can carry batteries up to 160 Whr but you are restricted to two. Most of my batteries other than my Trex are 3 cell. I figure then I could carry up to a 2200mah 3S then on the lithium restriction.
Watt Hours = Nominal Voltage x Amp Hours

So a 3S 2200mah is 11.1 volts x 2.2 Amp Hours = 24.42 wh or lets just call it 25 wh.

I fly a lot and the real issue, especially today is TSA freaking out seeing batteries in your carry on baggage. Expect to get the third degree and extra time they will take with you might not be pleasant. TSA, well the public for that matter are not familiar with RC Hobby LiPo batteries we use.
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Old 10-07-2017, 10:37 PM   #6
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Originally Posted by dereckbc View Post
Watt Hours = Nominal Voltage x Amp Hours

So a 3S 2200mah is 11.1 volts x 2.2 Amp Hours = 24.42 wh or lets just call it 25 wh.

I fly a lot and the real issue, especially today is TSA freaking out seeing batteries in your carry on baggage. Expect to get the third degree and extra time they will take with you might not be pleasant. TSA, well the public for that matter are not familiar with RC Hobby LiPo batteries we use.
I agree. I fly a lot too and they tend to be mindless robots but, when they do use their minds it's usually to freak out about things like this. Though they usually are more hawkish about dangerous things like bottles of water.
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Old 10-08-2017, 01:17 AM   #7
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We spent 2 weeks down in Texas with our daughter a few years ago, I bought a EPP plane that lent itself to being cut apart and then glued back together with a carbon fiber spar.

I boxed plane, 3 1000mah Lipo's, charger, glue, CA, and a few parts, and shipped it down there to arrive after I got there. I think I used UPS.

I made a cardboard box around my JR 9303 Tx and put it in my checked suitcase.

No questions were asked at that time about anything, however things may be a lot tighter now.

Did the same on return. Shipping was less than an extra bag. I was going to fit it in a suitcase.

Dave R, KI7MTA Proud PGR rider.
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Old 10-11-2017, 08:24 AM   #8
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No, a 3000mah 3S 11.1v battery is not would be 1000mah per cell, it means three 3000mAh lipo cells in series, each cell capacity is 3000mAh;
you can read this Lipo Battery Comprehensive Guide will help you know more about Lipo batteries.
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