RC India

Dear Friends,
I would like to share my build experience of 3S battery pack using Panasonic NCR18650B battery. Wanted to build this for my QAV 250 quad.  Will post the results and flight time after couple of days as I am really busy with my office work.

Materials required:
•   3 Numbers - NCR18650B battery
•   Wire for + and - ve leads
•   3S JST XH wire for balance charging
•   Double side Adhesive tape and black wiring tape
•   Zip ties

Step 1:
Just placed the batteries in series on top of the adhesive tape and wrapped it so that it had a firm grip and on top of that zip ties so that it cant move.  Then took a sharp edged knife and scratched the top of the batteries so that it will be easy for soldering.
Step 2:
Soldering the batteries in series as show in the picture. Next  soldering the positive and negative lead wire for charging.  After that connecting the 3S JST XH wires for balance charging. To make it firm I just wrapped with tape and thats it. All set and done. Battery pack is ready and as shown tried to charge it using lipo balance charger and you can see its getting balance charged and the total voltage is showing as 11.5v. Need to charge this full to attain the maximum capacity.

What C rating did u get out of it?

@ Rathi,

I have not yet tested the C ratings. what company claims is 1 to 1.5c.

I think Panasonic NCR18650B is a lithium ion cell.Multi chargers do have option li-on cell. I also tried to make a 3s battery pack by using a lion battery but it didn't gave enough rpm to the motor(as discharge rate is very low), after i added one more cell n made a 4s pack the result was same rpm increased  little high but yet not enough to airborne. Finally i converted it into 2s pack n working good in my tx, could also be used  in rx by BEC PPM connector. Always use safe bag or any secure strong box while experiments with batteries as if something goes wrong  it may not sound good. Let me know how it works,,,,

..

Very interesting DIY but I am not sure if it will be able to provide enough current for your QAV250. After all I use 45-75C LiPos while this one is only rated for 1 or 2C. I think this would be OK for endurance quads or fixed-wing aircraft where the average current draw is much lower. Just out of curiosity, what is the main advantage of using these batteries over LiPos?

they are lighter and smaller than lipos for their capacity, they dont pack a punch but it can be packed they way u want it.

@ Nithesh, Yes agreed need to use the battery safe bags while charging. Will test and let you know if it has the power to lift the quad or not. Hopefully from the few videos which I have watched they have used it without any issues.

If it flies okay
if not use 1 more 3s pack in parallel.
I.e. 3s2p

The Panasonic 18650 B is the
battery powering the current
generation of Tesla Model S
and as such receives good
attention.
Wow.

@Tanmay,
That is exactly my plan.  If it doesn't work then will add parallel batteries to it.  3s2p

But slightly worried about the weight factor.  Will the 250 quad able to lift 6 batteries weighing around 320gms?  Can someone Pls confirm.

I just want to ask that you use brand new 18650 or cell salavged from old laptop batter  and if new then price

But then doesn't that defeat the point of using LiIon packs over LiPo - weight savings? It should be able to lift 320g depending on your power system but it won't fly too well. The low C ratings are limiting the power you can get and the battery is heavy as it is. The biggest pack I use on my ZMR250 is a 4S 1800 75C and it has plenty of punch though it weighs around 200g. I still think a LiPo is a better choice for this application. The LiIon packs may be good for a Tx, FPV ground station, endurance plane etc.

Thats the point .  those packs are good only for low kv low amp motors. Or planes.  a 250 isnt the right platform.
But this doesnt meam that you stop experimenting . Go on and you might discover new things.

And finally the MAGIC happened today. Yes guys it worked to my surprise the QAV250 started to fly with the NCR18650B batteries with just the 3S setup. I just didn't bother about anything and went on to built the qav250 as early as possible to check if the 3S battery pack worked. And YES, I am extremely happy to share that it did work. Not sure guys if you ask me about the C rating I would be able to tell anything at the moment.

If it had punch or not I am not sure but all that happened was it started to fly.  I am extremely satisfied that it did work . (:|~
 

http://www.youtube.com/watch?v=bShxv3Y6aEo (http://www.youtube.com/watch?v=bShxv3Y6aEo)

Some closeup shots of Quad with the battery pack !!!

my suggestion would be dont try it again. if you had a OSD on you could have seen that the voltage sag would have been really large. And your pulling way too much a 2c battery can handle. just by the look of it i think the voltage during the sag would be less than 10v. if you are using a fpv system its really bad. and the battery is going to puff and later anything can happen(watch youtube ;-) ).

And just as a precaution, u might wanna have heatshrink ur female bullet connectors completely so u see no brass coming out to make it nice and insulated , the ESC gets spoiled if any of the two esc to motor connections touch each other by chance and that mid flight can be really bad.

Today I did a flight time test using these battery and results were not extraordinary but was definitely not that bad. Batteries were fully charged at 12.6V with each battery at 4.2V. Until the voltage dropped to 10.6V the flight was extremely good but then after that it lacked the power. I got around 7 to 8 minutes overall which is not bad. I have not tested with LIPO and have ordered one 1250mah lipo from RCbazzar. Hopefully should get it in a couple of days time and will check the flight time compared to these batteries.

I think these batteries would be best at 4S setup rather than the 3S and would definitely get more flight time and the punch that is required. Overall the batteries were not really getting hot both while charging and also after the flight. It remained at normal temperate but slightly warm after flight.

 But now it is very evident that these batteries perform well even in higher KV motors and not that it is only suitable for lower KV motor. But one thing for sure whoever uses it in planes will get extremely very good flight time. Any other suggestions to improve are most welcome.

@ Rathi,  Yes agreed I should have completely shrink wrapped the female bullet connectors. Not sure why my brains didn't work at that time and how I missed it. All that was running in my mind was to test these batteries and could be the reason I missed it.  ;D

 

Very interesting results. How much does the battery weigh totally? What is the total capacity? If possible could you post a BlackBox log so we can see how the pack voltage is varying in flight?

Could you also post some details of your quad setup and AUW? Also, I would recommend getting rid of those bullet connectors. I prefer directly soldering the motor wires to the pads on the ESCs. Neater and reduces weight. I wouldn't recommend RCBazaar LiPos, especially for something like a racing quad. IMO they can't handle high discharge and mini quads usually draw a lot of amps (though it depends on your setup) . I had one cell of a Wolfpack 2200 25C (calculated max discharge = 55A) die on my Reptile 500 (which can't draw more than 52A even on full throttle, which I never reached). I converted it to a 2S and now I use it to power my FPV goggles

PS: You have a lot more guts than I do. I would never dare to fly my ZMR250 indoors ;)

Nice results, looks like your getting really good flight time considering the low c rating of these cells and that they should only be able to output 6-7A at the current configuration.

What is the weight of this pack?
Also do consider that a similar 3s lipo costs approximately the same and gives you more c and probably identical flight times.

This is a good pack for planes though if it is under 100gms some small planes may be able to drastically improve flight times. :)

@SK1701 and RCNeil,

Total weight of the battery with tape and wire weighs around 170gms. I could have definitely reduced some weight here but have put lot of tape and winding. AUW is 530gms. Please check out the pics. Capacity of the battery is 3400 mah but the point is we are not able to use the capacity of the battery because of voltage limitations.

I have no idea of blackBox log. Can you tell me how to do and measure it ? I can then give you the results.

Not a big deal I will remove the bullets may be sometime later. Friend I just ordered and LIpos yesterday and now someone says its not good ...oh dear...If I would have known this a little earlier would have cancelled the order. Anyways will keep it as a spare if not good.

Quad Setup:
Emax MT1806 2280kv motors
12A Simonk ESC
CC3D
5030 propellers

congrats sarvan sir   
b

awesome work sarvan , :thumbsup: :thumbsup:

I have some questions regard these batteries.

cost of each battery ?

time to charge the entire pack of 3 or 4 cell to the peak...?

how many number if charge-discharge cycles can this battery provide.?

regards.

mada

http://www.ebay.in/itm/2x-100-ORIGINAL-Panasonic-NCR18650B-3400mAh-3-7v-Rechargeable-Battery-FlatTop-/252303853331?hash=item3abe7b4713

@madaquif, this is sarvan_me's store itself, these are phone batteries and need a special li-ion not a li-po battery charger and it depends on what amp setting u put it on... it can give many charge cycles but i dont know about the aprox numer.

https://na.industrial.panasonic.com/sites/default/pidsa/files/ncr18650b.pdf


hopefully this helps  ;D

1 c is the usual that u get

@madaquif  and Rathi,

Just to answer some of your questions. These are industrial batteries mainly used in flashlights and high drain equipments like welding instruments and also in ebikes & Cars.

If you do a battery pack out of this you can charge it using a lipo balance charger itself. Maximum recharge cycle is 700 -800 times.
Max C rating is 2c. 

Yes I basically did this battery pack to prove to one of the buyers that we were selling only original batteries in our store and hence I landed here. :-) 

From what I analyzed there are other high drain batteries better than this like Samsung IMR 18650 - 25R which can give much better C ratings. Will try to source in those batteries sooner or later.