### The Brown one is 3000Mah, the white one is 4000Mah

Let me ask you, what is the difference between the two?

Do not go for the obvious like size and color, both batteries are the same width and height but the white one is less than half the length.and about half the weight as well.

They are also both the same voltage, but the brown is 14v 3000Mah

the white one is 14v 4000Mah.

In case you didn't know these are lithium Ion batteries.

They charge to the same voltages and discharge to the same voltages, they can be used with the same chargers as lithium polymer batteries but as you can see are much smaller and more durable.

This is because they are similar to AA batteries, they have a metal casing.

This means any crashes are less likely to kill your battery.

So I will be building these packs to sell on for you guys.

You can build them yourself if you like just have a google for some sources to buy the cells from.

I am planning to sell 4500Mah 4s  size wise they are a tad smaller than a 2200Mah 3s Lipo and a bit lighter.

I am aiming to sell them for about £8-£12, a equivalent lipo

(cheapest on hobbyking was £21.50)

And 4s 1000Mah

This is about half the size of the white pack above.

The reason i wont be selling the white pack 4000Mh 4s is due to supply issues but i may in the future.

but in the future i want to expand

3s 45000Mah

3s 4000Mah

and custom batteries will also be on the agenda.

If you are interested in these packs, have a look on blog history, another member of DIYdrones has posted about them previously,

and if you would like to buy a pack now, i will start selling the 4500Mah packs in about 3 weeks after further testing and built technique experimenting.

Just PM me.

• So when you are testing batteries and finding their max discharge rate you can use Amps divided by Capacity(in Ah not mAh) to solve for the C rating.

• Gary is pretty close for explaining the C rating.  Basically "C" x "Ah" = amps.  Starting with a 2C 5000mAh cell you can pull 10amp (2C x 5Ah). So when you put 2 cells of 2C 5000mAh packs together in parallel the C rating doesn't increase, the capacity does to 10000mah (10Ah).  So the C rating is still 2 but you can pull 20amps since you doubled the capacity. Putting cells in series has no effect on the C rating, capacity in mAh or Ah (Wh is a different story), or the total amps that can be pulled.  It only effects voltage.

• Hi Jared, 1c on a 1000mah battery is indeed 1 amp

1c on a 2000mah battery is 2 amps

and 1c on a 5000mah battery is 5 amps

putting batteries in serial connection does not increase the C rating.

Putting batteries in parallel does increase the C rating.

for instance two 1C 5000mah batteries in parallel = 2C total discharge rating = 10 amp acceptable discharge rate.

Reality is most lithium batteries have a 2C discharge rating and the only way to increase the discharge rating is to put them in parallel.

so the above example would really be: two 2C 5000mah batteries in parallel = 4C total discharge rating = 20 amp acceptable discharge rate.

I am pretty sure I have this right, but if somebody else knows better, please jump in and correct me.

Best Regards,

Gary

• Forgot to finish my thought.  I agree that these batteries for multi-copter may not be the desire power source with multi-copters demanding much more C ratings for lift.  For aircraft such as a Raptor 140, these are more than enough for take off and sustained flight.

Trent shows his 4S Li-Ion configured battery pack has twice the watt hours of juice than does his 3s Lipo 2200 mAh pack.  He was comparing nearly the weight between the two but the net gain in watt hours on the NCR batteries.

@Jared Reabow, Help me to understand how you're accomplishing a C rating of 35.

Based on what I see you are running a 4S configuration.  How exactly are you able to achieve a 35C rating?

Best I can see is probably no more than a 2C rating and optimal 1C.

• noope the 1000 mah are about half the size of an aa

the 5000 is fatter and longer than an aa.

ill do more tests on c raings because i do not want to disappoint people.

• Jared: Sounds like a dream come true! The ideal size is "no wider than 51mm and no higher than 35mm". The length could be around 150mm.

I need 4S at about 40A cont with peaks of 90A,

I'm not sure I understand everything though, are the cells the same size no matter the capacity?

"

nope its not 2c hehe

they are in 2p configuration"

• @Dan Murray

Check out Trent's video at http://www.mygeekshow.com/watchmygeekshow/episodes/Episode_144_NCR1...

He explains the C rating of these batteries.  They only really produce a max peak of approx 8 amps or

This episode illustrates the batteries capabilities.

http://www.mygeekshow.com/watchmygeekshow/episodes/Episode_146_NCR1...

Also review Panasonic's site http://industrial.panasonic.com/www-cgi/jvcr13pz.cgi?E+BA+3+ACI4002...

• if someone could explain how c relates to amps i would appreciate it.

as far as i know 1c on a 1000mah pack means 1 amp

• i didnt say 2p hehehe

i said 10p