NCR18650B: A Lithium Ion battery with a ton of promise! People say it has twice the energy per gram as LiPos... but is that true? Lets test it!
But it doesn't stop there! I want to know how to actually use this on an RC Aircraft, how to charge it, what it's maximum amp draw is, how many watt hours of power does it have, and in the end, can you actually use these on RC aircraft?
I think I've found the answers to these questions!
Battery: Panasonic NCR18650B
Grams per Watt Hours is 57% that of a typical LiPo
Pack Capacity: 3.3Ah (3,325mah)
Pack Voltage in 4S: 14.4v
Pack Power: 43 watt hours (personally tested with a watt meter)
Pack C-Rating: 2 (6amp max discharge rate)
Pack Cycles: Hundreds! I've not personally tested this, but this is the same chemistry as an iPhone, which can last years of daily use.
Buy the battery pack here: http://store.mygeekshow.com/product-p/3.3a-4s-2c-battery.htm
-Trent
Comments
Hi Peter, 18650's are completely unsuitable for your copter because of their low C rating.
To use 18650 really requires a very specific highly optimized design to run at maximum efficiency to get current draw low enough.
Hobbyking has a new Multistar battery whiich is rated at 10C with a 20 C short term over capability that is infinitely more practical for normal use and results in about a 25% weigh saving per total energy over a conventional LiPo:
http://www.hobbyking.com/hobbyking/store/__1388__1145__Multi_Rotors...
The other possibility if you have lots of money are the very highly optimized MaxAmp batteries.
They also enjoy a 20 to 25% weight advantage in a variety of C ratings but they are not cheap.
Best Regards,
Gary
Hi Peter,
unfortunately these batteries are not really suitable as drop-in replacement for existing copters. In your case, I guess you will heavily overload these cells, as 25mins are more than the allowed absolute max of 2C. Keep in mind: the LiIon batteries are brilliant for use cases with 1C or less, which is equivalent to 60mins or more.
The most promising recipe: reduce the weight. As a reference: my current FPV copter with 15" props weighs about 900g without battery, but with all FPV stuff. Using a 5s3p Panasonic battery, I can fly for about 1 hour with this copter (cruising at moderate speed, maybe 5-8 m/s).
Additionally, you should take care about your maximum currents (4C). For a given drive setup you therefore usually end up running some cells in parallel (3p in my case). As a nice side effect, it increases the capacity, but also the weight and therefore the average current.
Hi guys!
Just stumbled on this forum as I did some homework on improving my flight times on my quadcopter - wow! Some smart minds in here! :)
Which is why I've gotta ask. . . after reading the 9 pages so far, it sounds like there are possibly 2 batteries suggested that out-do typical LiPos? I'm excluding the GEB8043125 because I'm really just looking for advice on "readily available" batteries - this one sounds tricky to acquire?
-NCR18650B/G/PD
-LG ICR18650D1
Honestly, is 1 any better than the other really? I would absolutely LOVE to get 25+ minutes of flight time on my machine! I'm no battery pro like you guys though. Would either of these batteries be okay for my system?:
- NTM Prop Drive Series 28-26A 1200kv / 286W @ 15v
- Turnigy Multistar 30 Amp Multi-rotor Brushless ESC 2-4S
- Gaui 330 sized frame (I custom built my own but it's pretty light)
- 900MHZ 800mW Tx/Rx & 1/3-inch CCD Camera FPV package from Hobby King
So weight-size wise, would I be able to use either of the 2 listed batteries in a 4-pack series to get some longer flights from my quad? Think it'll give me enough juice to lift with the motors, esc's I've got?
Sorry for the dumb sounding question guys, I've just never better that smart in all the battery calculation stuff :)
Thanks for the help and advice! :)
I contacted the company , the cell's are 13 usd each which is not bad ...
BUT the cell cycle life is 50! after 50 discharges the cell is DEAD.
This kind of stuff is made for military / big budget commercial.
The new NCR18650G Panasonic cells are better ~ 260 wh/kg but Tesla got them all ...
Of Course you are right, given the extremely wide range of the battery technologies themselves the 2 to 1 comparison is really a moving target.
It just happens that the individual cells/packs that I picked actually did work out to very nearly a 2 to 1 difference in weight.
Basically Trents 3300mah Panasonic 4 S pack at 48 grams per cell = 192 grams versus HobbyKing 3300mah mah pack at 425 grams add wires, plugs and shrink wrap to Trents battery and it should be really close to 2 to 1 actual weight difference.
If that 2 to 1 battery weight difference can be (more or less) counted on it actually makes it really easy to calculate hover / flight times in Xcopter calc because their 123 battery specs don't come close to these lithiums.
Just calculate it with a standard LiPo and then double the flight times for the lithium of twice the mah rating.
Does deal only with weight, not volume.
(I do understand the limitations of this method).
I have 2 different quadcopter designs based on this battery that I think coud actually be used for real applications.
One a medium sized one with 15" props that could support a goPro and brushless gimbal as well as FPV and telemetry with a useful flight time around 30 minutes and max hover time approaching 60 minutes. 4S-2P lithiums.
And a small light one with 10" props that could support Fat Sharks new HD FPV with about the same flight times. (2S - 2P lithiums for this one).
Just theory of course, but I'm actually building the small one currently, so we will see.
Best Regards,
Gary
@Quadzimodo: That's my battery spotwelder, yes :)
I guess, in short, there is no 2 to 1 ratio between LiPos and Li-Ions. There is just a big difference in the context of our discussions here because we are comparing Prismatic Super High Power LiPos with Cylindrical Super High Energy Li-Ions. Plus, of course, we are stretching the truth when we say 2 to 1 (I am certainly guilty of this).
In the examples I give above, the NCR18650Bs are only 62% more energy dense than the Nano-Tech. 62% is a big difference, but it is a long way from 2 to 1.
Gary - Sorry mate, wasn't sure the distinction was clear.
I am not quite sure why the chart does not reflect the 2 to 1 ratio between prismatic Lipos and cylindrical Li-Ions we see currently.
Turnigy 3S1P 8400mAh (40C/80C)
11.1Vx8.4Ah=93.24Wh (@641g)
(93.24Wh/641g)*1000g=145.46Wh per kg
The Turnigy Nano-Tech example above falls short of the energy density range given for LiPos in the chart (by about 20Wh/kg or 12%). This could be because the Nano-Tech is optimised for power density rather than energy density, while the chart ignore power density. A LiPo example with a more conservative C rating would perhaps be a better comparison to the NCR18650B and reference for the chart (have not checked to confirm, just seems reasonable).
Panasonic NCR18650B 3S4P 13600mAh (2lt continuous/3lt max)
10.8Vx13.6Ah=146.88Wh (570g + 50g for tabs, leads, plugs)
(146.88Wh/620g)*1000g=236Wh per kg
The Panasonic is well above the range given on the chart for Li-Ions (by about 35Wh/kg or 17%). This might be because the chart is outdated. It might also have something to do with the fact that the chart was lifted from a brochure marketing a competing cell - the UR18650ZT. Interestingly, the UR18650ZT is a cylindrical Li-Ion which has a stated volumetric density of 576Wh/l and an energy density of 203Wh/kg (positioning it at the very cutting edge of the range given for Li-Ions in the chart).
Hi Quadzi,
I know Lithium Iron Phosphate is a different technology and in practical terms their weight/size to energy density is quite comparable to the actual LiPolys that we are using to day. Although discharge rate is a bit lower but number of charge cycles is better and much less tendency to flame out.
What is interesting about this chart is that it does not show the 2 to one difference between prismatic LiPolys and cylindrical Lithium Ion batteries that actually seems to exist currently.
The Panasonic 3300mah Lithium Ion cylindrical cells now available weigh ~48 grams, on a cell for cell basis this is almost exactly half the weight of the better optimized equivalent prismatic LiPolys "Turnigy Nano for instance".
Based on size comparisons, it doesn't seem up to date on volumetric density as well, also seems like the Panasonic and LGB lith-ions are performing well beyond this chart.
My comparisons were made based on actual published specifications, weights and sizes, so there is probably some discrepancy based on various packaging techniques, but not sufficient to entirely explain discrepancy.
Best Regards,
Gary
I suspect that the chart might be a bit out of date and not reflective of the current state of the art in the Panasonic or LGB lithium ion battery chemistry's.
Tilman - This chart gives a good guide to comparing technologies. LiFePo4 is not included in this unfortunately, but I think this would be positioned a bit lower than LiPo.
Tilman/Gary - LiFePo4 is a different technology to both LiPo and Li-Ion. A123 Systems is probably the most well known battery manufacturer of LiFePo4. They unfortunately went belly up and their assets were purchased by Johnson Controls. As I understand it, the real advantage promised by LiFePo4 was power density (rather than energy density) as well as longer service life in heavy cyclic applications (like cordless drills and hybrid buses).
ALL - Here is a good thorough test by NASA on the NCR18650. It states capacity is 2.9Ah which suggests this test is on the PF variant, however the fact that the test was conducted in 2009 puts this into question. With that said, it seems reasonable to assume that NASA might get it's hands on these things before they are put into proper production and sold on the open market.
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